Methods and devices for transmission and receipt of information
FIELD: radio engineering.
SUBSTANCE: in accordance to method, transmission and/or receipt of information are performed by means of waves, in accordance to which superposition of information signal over carrying wave is performed, frequency of which wave changes continuously and smoothly on given time interval for generation of at least one scanning of bearing, while signal being transmitted after receipt is filtered in frequency area for separation of multi-beam components or cleared from interference and then estimated relatively to signaling parameter, carrying information.
EFFECT: increased data transmission quality, increased resistance to interference.
4 cl, 41 dwg
The invention relates to methods and devices for transmitting and/or receiving information.
For the transmission of information through the waves are, as a rule, constant carrier frequency, and the quality and speed of transmission is often limited by interference in the transmission channel. Real transmission channels may have very different properties, can represent different transmission characteristics, which can include linear and nonlinear distortion, fixed and variable time effects, and additive noise (noise), the influence of extraneous signals, etc. When using systems with multiple carrier signals, and for transmitting on channels with memory special problems creates multiple mutual interference. The properties of the transmission channel are the result of different effects and mechanisms that can interact in various ways.
A complex problem is a (often non-stationary in time) multipath signals. It is shown, for example, when passing through an inhomogeneous medium in a structured space transmission, etc. in which the transmitted signal is reflected from various boundary surfaces and/or around their edges or scatters them. In such cases, the signal enters the receiver not only in the direct path of the spread is anemia, but at the same time or with a shift in time and with varying degrees of attenuation and in various other ways (multiple entry). In addition to the effect of different lengths of pathways, some paths may make various changes in the corresponding signal components in view of their geometrical characteristics and/or individual physical properties (different degrees of attenuation, nondeterministic and/or deterministic internal phase shifts). These individual signal components called multipath components (echo signals). Each of the multipath components brings their own content to the receiver, where the multipath components are added. The sum of multipath components at the receiver can lead to poorly predictable temporal and spatial distortions, variations in the amplitude and phase shifts (lost and the sinking of the signal), and in unfavorable cases it can cause a complete compensation signal. This effect is particularly damaging in the unstable conditions of the transfer, as well as when using a mobile transceiver systems. Loss of signal is often selective in frequency and in time, and the transfer function of the channel is often impossible to determine in a deterministic manner.
In communications technology, there are various the ways with the help of which try to minimize and/or compensate for the above-mentioned interference at reception. From a great variety of such measures can be divided in three main categories: antenna systems, the conversion signal on the receiving side by using offsets, as well as special methods of signal modulation.
In so far as conditions allow transmission or system configuration, the problem of multipath propagation can be reduced by targeted radiation and/or selective angle of the receiving antenna. When the directional radiation are trying to form, if possible, only one certain, usually the direct path signal, which then focuses the radiation energy. At the election on the corner of the reception trying to registrovat unwanted multipath components of the received signal, or by specific inclusion of multiple receiving elements to provide for the imposition of these components for their mutual compensation (in other words, the energy of the respective signal components is destroyed), so the possibility remains only one multipath component of the useful signal. This signal component respectively amplified. Through reception of a signal simultaneously in several points of the space, you can implement the antenna gain. Pre is the property and limit the beam forming at the reception can be demonstrated on the example of the acoustic data under water. At a small distance can be achieved obvious improvement in the reception quality. This receiver is equipped with a grating receiving items using delay elements allow you to implement the restriction and the orientation of the reception angle and thereby to a certain extent, to implement a focusing system for receiving a particular multipath component [see, for example, Hinton, O.R. et al.: Performance of a stochastic gradient adaptive beamformer for sub-sea acoustic communication. Signal processing VII: Theories and applications M.Holt, C.Cowan, P.Grant, W.Sandham (eds.), European Association for Signal Processing, 1994: pp. 1540-1543]. Based on the angular correlations of the system works, however, only if a sufficient ratio of the depth to the range, i.e. typically at small distances and involves fairly stable properties of the transmission channel. For many applications (mobile etc) aimed (depending on angle) receiving and transmitting system can hardly be practically implemented due to their size and weight, and are not appropriate from the point of view of their application of the basic principle. Here the focus is often even restrictions in use. On the contrary, seek to ensure that vsenepremennoj transmitter and/or receiver. Compact antenna should be more or less limited to a single point in space.
The next opportunity for combat somehome when the transmission is in the preparation of the received signal for processing in the receiver. In principle, the development focuses on the development of increasingly complex procedures for processing a signal using expensive proofreaders, fasolada circuits and other complex correction algorithms, which are due to the technique of digital signal processors are implemented more effectively. The problem of multipath propagation are trying to solve in particular by the adaptive correction of the propagation time of the signals. For the correction of the echo signals are used, for example, transversal filters, in which the properties of the transmit channel is estimated using the correlation analysis of the known signal elements. In addition, usually on the basis of the transmission of the test sequence is formed complex-conjugated signal as Inverno transfer function of the channel is used for convolution with the subsequent signal sequence, the modulated information to suppress interference. In adaptive systems, the offset is adjusted to compensate for the propagation time (correction proactively - KU). All of these methods operate in the time domain. As a consequence, the adaptive correction for data channels with time-varying variance rate is practically impossible. [Meineke; Gundlach: Taschenbuch der Hochfrequenztechnik, Springer-Verlag, Berlin, Heidelberg, New York..., 7. Aufl., 1992: H 21].
Already been done n the torture to solve the problem through various combinations KU, proofreaders with adaptive decision feedback (KAROSA) and/or fasolada circuits (DSF) of higher order. Despite significant challenges in constructive performance and signal processing, the results are still unsatisfactory. Adaptive tuning offsets are not able or do not have sufficient speed and/or sufficient accuracy, causing loss in signal-to-noise ratio when performing correction is inevitable.
Another known method for improving the transfer results in noisy environments, and also due to multipath and multiuser access, etc. in terms of intersymbol interference is to use multiple modulation. In this respect, particularly significant are the ways of the spread spectrum signal in which a modulated signal is "stretched" in a wide band of frequencies. The term "expansion of the spectrum" refers not to the transmitted information, and to the structure of the carrier. Due to the wide bandwidth of the transmitted signal transmission channels in a broadband system can be used even with relatively low signal-to-interference. The essential properties of the system are the way to distribute the signal energy over a wide range, the transfer method for the enhanced spectrum signal, as well as about Atego conversion distributed spectrum signal to its original bandwidth of the information signal. Depending on the application use three basic methods of modulation: direct modulation sequence (MFS), also called "pseudotumor (PSH) method, the modulation method and frequency-hopping (HRS) and the method of frequency modulation (FM).
Well-known advantages of the expansion of the spectrum are the selective addressing, multi-user access via a code multiplexing, masking data, increased noise immunity, low power spectral density signal for protection from eavesdropping or interception suitable for use in the methods of measuring ranges with high resolution, etc. the disadvantages include increased system requirements, including the complexity of the timing of receiving and transmitting devices. Signal distortion due to multipath propagation can be significantly reduced, but still embody a number of problems.
In the proposed context, of particular interest are methods of frequency modulation or FM. They find important applications in technology radar or acoustic location and communications engineering. Feature is the use of pulsed radio frequency (RF) signals whose carrier frequencies vary continuously or obolyut in particular rose frequencies within a certain pulse width.
FM signals provide favorable energy distribution in the frequency band, which makes them resistant to interference, provides a more effective recognition and improvement of the signal-to-noise ratio. However, the advantage of this method is that you can significantly reduce the transmission power.
The transmitted signal can be formed in various ways, for example by means of a generator driven changing linearly on the input voltage. The way FM is used mainly linearly frequency-modulated pulses. One of the ways intended for linearization of systems with lobularia frequency, as well as the value of the chirp signals, in particular for radar and described, for example, in the patent DE 19527325 A1. Interesting is the fact that the radar in such signals are to be paid a special "marker" for the improvement of signal analysis.
When sending messages (through sound, optical or radio signals) are applied, however, mainly noncoding frequency-modulated signals, which can easily be produced through the filters - generation of FM signals or a dispersive delay lines. As the dispersion filter is used, as a rule, components for surface acoustic wave (saw). However, the configuration of the frequency-modulated signal is Alov sets constructive means.
When the digital message transmission by means of frequency-modulated signals we are talking mainly about the distinction between two opposite States on"/"off", where "on" is sent in the form of FM pulse.
In the U.S. patent And 5748670 described method, which additionally allows to distinguish the state of the chirp signal with positive and negative slope of the law of frequency modulation. To increase the density of information it is possible to vary the amplitude and/or phase of the world Cup. This does not change, however, nothing in principle, because in itself the world Cup suggests limited opportunities to change the structure of the carrier, which is a big drawback, for example, in multi-user systems for the implementation of multi-user access to the channel.
It is known that each of these ways of expanding the range has its own specific advantages and disadvantages. However, there is the possibility of combining them in different ways. By means of hybrid methods is ensured by the creation of new systems with improved (compared to the individual methods) properties, and the system cost is not necessarily doubled. The most famous hybrid systems are: WBC/WBC with RAP or WBC/PSH, abrupt change in time frequency (CIVC), the abrupt change in the time-SIV)/SICH; SIV/RAP, chirp/SICH, the chirp/PSH/JM (phase shift keying). In this system, the chirp/PSH/JM have a greater variety of waveforms, due to the PN modulation, but due to the chirp - minor deterioration when the displacements of the center frequency due to Doppler or other deviations in the frequency between the transmitter and receiver.
For completeness it should also be noted that in the technique of mobile communication are experimenting with ways in which prior information signals modulated in the usual manner, is sent with a preamble consisting of a sequence of frequency-modulated signals to facilitate synchronization of the transmitter and receiver using a "header". Conversely, there are also ways in which narrowband header with a constant carrier frequency is combined with the chirp sequences (temporal ordering of the chirp sequences and other forms of signals).
The above modulation methods are mainly in the pulse signals, and fall into the category of non-coherent transmission methods, which are particularly resistant to interference, but allow transmission of data only with relatively low speeds. In order to meet the growing needs in data transmission rates and multiplayer modes should be taken is about the attention of all the possibilities to improve the degree of channel utilization and throughput. It is known that by applying visokogradnya structures of the signal significantly increases the speed of data transfer, which, however, due to low noise immunity of such signals leads to a further increase of costs needed for signal processing or requires special additional measures.
Professionals also know that in the technique of mobile communication experiments with fazokodirovannymi signals of longer duration, which extend along the spectrum with additional modulation chirp signals. The latter are generated by a generator, voltage-controlled and do not require expansion and then contraction of the signals in time, as in the case of the filters on surfactant with subsequent transfer and processing. The transmitted chirp signals are transmitted without additional header to each other in predetermined time intervals. Since, according to this data transmission method, all carriers have the same frequency gradient of scan lines parallel to each other, and time intervals are selected so that although the scan time may overlap, however, the current bandwidth must always be clearly separated from each other. Thus, at least in the field of radio frequencies there is the possibility of using more complex f is the RM signal modulation to encode information. By sweep (sweep) frequency is attenuated or even eliminated the effect of fading. When using this method, however, difficulties arise in the process of signal processing.
For the separation of scanning lines received chirp signal is converted temporarily into a narrowband signal of constant frequency and filtered. On the basis of the filtered signal is estimated transfer function itself filtered signal is transformed back into the form of a frequency-modulated signal (for its correction in the form of a frequency-modulated signal and then demodulated and passed down as a narrowband signal analysis parameters.
One source of problems is that the correction signal is generated on the basis of narrow, however, it is difficult structured, especially in conditions of multipath propagation of the transmitted signal. In the case of multipath propagation the signal always contains a range of different frequencies. This, however, is not taken into account. The result is in any case the fact that when the exponentiation and then taking root to extract modulation, carrier information, there is a mixture of frequencies, from which it is impossible to obtain high-quality transfer function. The more multipath components and the more different the time, even more significantly expressed this problem. In that case, if the individual multipath components additionally have their own variables and time distortion (different Doppler shift and the like), there is a perfect chaos. The function of the corrector is formed then the highly noisy signal. This source of error generally responds poorly to treatment correctors operating in the time domain; the problem of interference only transferred to another plane, but not solved.
All known yet how multipath signal is considered as a disadvantage, against which try to fight all the known methods, instead of using echo signals as an additional set of signals provided by the nature of signal propagation. For this purpose it is necessary, however, first perform the separation of the individual multipath components. All used up to the present time, the chirp carrier signals of frequency gradients are too small, and the patterns are generally too rigid, in order to take advantage of this opportunity. Attempts have been made parallel operation of multiple proofreaders to use two or more multipath components with the aim of obtaining a system of winning and dost is in keeping superior results of processing the received signal. The applicant, however, is not aware that such attempts have been implemented in practice. In any case, because of high costs of large-scale use of this approach is questionable because of the unfavorable relationship of cost of the system to its usefulness.
In principle, in communications technology, seek to obtain, whenever possible, an undistorted copy of the transmitted signal (useful signal). Changes in terms of signal transmission, are perceived as interference and, consequently, attempts to weaken them, to compensate or, ideally, completely eliminated. However, you lose the information transmitted signal received in the distribution process on the transmission channel.
On the other hand, to determine the location and dimensions radiate among other signals, so that, on the basis of changes of the signal to obtain information about the spatial-structural and physical properties of the transmission channel, its profile and/or the objects it contains, for determining the position and motion parameters purposes. For this purpose, as a rule, FTA signals or signals with special markers, and these markers serve as auxiliary means for processing the signal, however, is not information like data.
In the patent application PCT/DE99/02628, published after the priority date of the current patent application (WO 00/11817), which is incorporated into the present patent application by reference, describes a method of transmitting signals, which first apply complex patterns of signals that simultaneously use multiple frequency-modulated carrier signals (channels with a gradient of frequency). In each case one of the channels is used as a support for demodulation or decoding of the remaining channels (data channels). For some applications, this approach is fraught with defects, or is not required when their data is assigned at least two channels, one of which serves only to transmit the reference signal and does not make any contribution in the actual transmission of information.
The present invention is a method and corresponding system for transmission and reception of information, simplified in comparison with the data transmission method with multiple channels with a gradient of frequency and provides high quality data, stability in relation to the above interference and having the ability to customize in accordance with different conditions of communication.
A method and system for transmitting and receiving information corresponding to the invention should in the first place about what especialy due to the improved signal processing and determination of parameters of the signal, higher data rate, and to ensure the transmission of multiple data signals in a predetermined frequency range simultaneously or offset in time to the best use of available frequency bands. In the same context also creates the opportunity for simultaneous use of two or more frequency ranges.
The method and system of transmission and reception of data must also ensure flexible formation and processing of signals that allow you to customize the structure of the signals in accordance with various special requirements, will ensure the processing of signals received from different points of view, especially the processing of multipath components separately, simultaneously or together for more winnings in the transmission of information and/or to extract from the received signal information about the distribution environment, which signal is acquired in the process of its distribution.
These tasks are solved in the method with the characteristics described in paragraph 1 of the claims, as well as devices with the characteristics described in paragraphs 32, 38 or 39 of the claims. Preferred options for implementation and enforcement of the invention claimed in the dependent claims.
The basic idea of the invention consists in forming the front of emago signal in the form of a carrier wave, the frequency of which is continuously changed according to a given law within a specified time interval and is the carrier frequency of the information signal, modulating it. When such a transmission carrier signal does not include any transmission of the reference signal. The transfer is made without reference components. Evaluation of the signal in relation to the information-bearing signal parameters is based solely on the information contained in the transmitted signal. For processing does not use any additional received signals, including any reference signals.
From a technical point of view, in this context, there are two different aspects of the invention are equally included in the present invention. On the one hand, the continuous change of frequency can be seen as a form of spread spectrum information signal that, in General, is not problematic, if such information signal already has its own bearing wobble. On the other hand, it is also possible that the information signal contains only the data for modulation of the carrier wave, for example, in the form of a modulation of the base strip, which is then directly modulates the carrier frequency-modulated signal.
For the presented invention which is significant, by continuously changing the frequency of a carrier signal uses certain properties in the data transfer process, which give the advantages in their use. An essential part of the method and device of the present invention, refers primarily to the special characteristics, as well as to the handling, preparation and transformation of the frequency-modulated carrier signals, and then, in what form, and as such the frequency-modulated carrier signals modulated in more subtle ways information modulation is rather secondary importance, if the corresponding information modulation does not lead to serious changes in the characteristics of the frequency-modulated carrier signal. In accordance with this subsequent presentation focused on that aspect, according to which the frequency-modulated signals are considered as the main elements of the carrier signal, however, other options are also not excluded from consideration.
In the present description, the oscillation frequency of which is continuously changed in a given time interval will be referred to as "scan" or "scan carrier". These concepts are used here as synonyms for the concepts introduced in the published patent application PCT/DE99/02628 (WO 0011817), such as gradient is essi signal" or like terms found in the technical literature, such as "Sobolinaya frequency or frequency-modulated carrier". For simplicity, the term "scan" is used here as an adopted concept for signal characterized by a continuous change of frequency.
The proposed method, which relies on the use of a carrier oscillation with a continuous change of frequency will be called here as "F2-technology" (from the English term "floating frequency technology" "technology floating frequency"or "S2-technology" (from the English term "sweep spread technology", "spread spectrum technology"). For use in connection is used as shorthand, such as " F2-communication" or "S2-communication" or "S2C".
In contrast signals with a constant carrier frequency here, by changing the frequency of a carrier signal, introduces an additional variable, i.e. an additional dimension, which, in addition to useful energy distribution of the signal in a wide band of frequencies, above all, leads to the fact that multipath components may appear in the process of signal transmission, can not easily overlap each other. The time delay is simply a shift in the frequency-time domain, in which corresponding components are consecutive, for example, when the chirp parallel to the Rog other, moreover, their relative removal is a function of the difference of time spreading and frequency gradient corresponding scan the carrier. The propagation time due to the nature of signal propagation and can hardly affected, while the frequency gradient is controlled by the parameter. When it becomes clear that the configuration of the carrier sweeps can be used in the proposed method as a tool with which it becomes possible to control the distance between the multipath components ("packing density") in the frequency-time domain, i.e. reducing the impact or elimination of interference effect.
In accordance with the invention, after receiving the signal is converted or transformed into another frequency shape in which the conversion takes place preferably in a frequency band or range, in which the carrier frequency is not experiencing any changes. One of the alternatives is the ability to filter multipath components using synchronously tunable filter, which, however, in practice, difficult to implement, followed by multiplication, convolution, etc. with a special processing function.
Using the preferred conversion is achieved that the multipath components are shifted in frequency times the second area, in accordance with their relative deletions relative to each other are in different frequency bands. Through such amazingly simple conversion is achieved very significant qualitative effect in signal processing, namely that the problem of separation of multipath components, each separated in time, are converted from the time domain to the frequency domain. A huge advantage is that existing methods of signal processing in the frequency domain provides the best overall results and implemented much easier.
For separation/purification from a variety of disturbances components may be sufficient to use simple filters, such as band-pass filters (PPF). In addition, these filters can be configured on components of interest; or, on the other hand, the respective components can be transmitted in a given frequency range, for example, by synchronizing the respective auxiliary frequency with the corresponding multipath component. In many applications, the use of such band-pass filtering may be sufficient to resolve major problems. In principle, in accordance with the proposed method, however, there is the possibility of processing spectral components of the received frequency-converted signal when what emeniem more complex filter systems alone, parallel block, if necessary, by combining them with each other in order to restore, or retrieve, or selecting parameters that carry information. This can be applied to methods known from publicly available sources on signal processing, which are not described here in detail. It is however necessary to emphasize that after the separation of the received signal in a range of fixed frequencies occur significantly more favorable initial conditions for the use of the above ways. In the process of separation of multipath components on the individual spectral lines of any form of interference and intermodulation diminished or altogether excluded.
In all previous methods, the problem of interference or the interference signal attenuation is considered as the main one. A large part of the difficulty in correction of the received multipath signal occurs, but also because of their individual and to the same variable during frequency and phase distortions, for example, due to different Doppler shifts. Intermodulation products of different Doppler components increase the complexity of the transfer function of the channel and the extremely short time coherence. Simple correctors are too short to establish a reasonably accurate function corrects and, longer offsets are too inert to keep track of all changes occurring in the channel, figuratively speaking, they "fall apart". In F2-cnoco6e such intermodulation avoided in the best way. Correction can be made for individual multipath components separately, which greatly facilitates the task, the preferred way reduces costs and provides the best results. Some preferred treatment options, as well as specific further development of the method described in connection with the relevant claims.
The proposed method provides the possibility of extracting from a received signal different information and use of the information contained in the transmitted or received signals and/or different modulation types. The user can determine how and to what extent it is possible to benefit from these opportunities.
One preferred application is the transfer of information between the receiver and the transmitter. Simultaneously and independently received signals can be processed in respect of changes acquired in transmission lines that provide the receiver with useful information about the characteristics and properties of the environment. For example, on the basis of the analysis of the frequency spectrum of a CR is reached and converted by the frequency of the signal, we can evaluate the quality of individual pathways, what can be taken into account in the data transfer process (for example, for correcting the position of the receiver and transmitter, focusing antennas and so on). In addition, by appropriate processing procedures specialist may receive a variety of additional data from the received signals. Used for the modulation on the transmission side information signal can be used, among other things, as a marker for improved handling procedures. In this sense, can get certain forms of modulation that satisfy both the above aspects. A variety of modulation methods, preferably applicable in the proposed method, referred to below in the description of the various forms of execution.
Support oscillation can be formed as an acoustic wave for solid, fluid or gaseous media distribution or as electromagnetic waves (for example, high-frequency signals, optical waves). The frequency change can be made in a given time interval, for the very simple suitable for many applications, case, linearly or according to a predetermined pattern predominantly monotonic continuous function or, for example, in accordance with the Gaussian function. Since the width of the available bandwidth, usually limited, the sign of the frequency gradient n the existence of oscillations should be changed at the end of the respective time interval (the turning point), or it must again be set to the value for example, the initial frequency. However, the support for oscillation falls into a number of elements that are called scan, or to emphasize the fact that we are talking primarily about the structural elements of the carrier wave - scan the carrier.
The invention relates both to the method and to a method of transmitting signals on the basis described above.
For signal transmission, the information transmitted is superimposed on the reamer carrier or a carrier wave with a gradient of frequency, i.e. the relevant parameters of the signal modulated in accordance with user-selected encoding method. The modulated carrier signal is designated as F2 signal or S2 signal.
In accordance with one preferred form of the invention, the support for oscillation is a sequence of scans bearing the same shape, which may be spaced from each other in time. The timing offset can be useful, for example, for natural attenuation of delayed multipath components or other feedback channel (defined as the echo of the acoustic signal). The ability to set variables distance between scans can be used, for example, to divide the information into separate information packages. Uh what about provides further basis for the application of multi-user systems.
In accordance with the invention, the scanner carrier may have various changes and tune in accordance with various tasks and conditions of transfer. For example, the scanner carrier with positive and negative slope can alternate intervals of time, and sweep the carrier can be rotated so that eventually formed a closed process, oscillating within a given frequency band. Can also provide multiplexing within one or more frequency bands so that the position of the frequency (start frequency) varied from scan to scan.
In accordance with one embodiments of the invention envisages the provision of higher data rates due to the separation of the sweep at two or more time cycles of modulation, which can have a variable duration. In one embodiment, execution not used the absolute values of the signal parameters, and their relative changes from one quantum modulation of the information parameter to another; with greater stability during data transfer in the conditions of dynamic noise.
For optimal use of the given bandwidth possible transmission of several signals in parallel (multiple module is aligned scans carrier). If necessary it is possible to use also a variant implementation of the invention, where instead of the multi-player mode or in combination with one sweep of the same F2 signal are shifted in such a way that they overlap in time. In addition, it is possible to transfer two or more scans with the distinguished, for example opposite in sign gradients (cross-scan) for double or multiple speed data transmission. Thus, this option contains a number of features to increase the speed of information transmission in a given frequency band.
In one of the preferred embodiments of the invention provides that a carrier oscillation is divided into two or more intervals having different frequency characteristics. At least one of the intervals is in the form of a sweep. This scan can be transmitted in a sequence of partially overlapping in time or concurrently with other portions of the signal, for example, shifted in frequency, but equally structured sweep carrier and/or in combination with a fragment of a carrier signal of constant frequency and/or in conjunction with one or multiple scans carrier who have a different, mostly FR the opposite, the tilt and/or have a different shape scan. Although this is clearly evident from the context, it is necessary separately to note that the scope of the claimed method is also an option when the transmitted sequence formed from two displaced relative to each other fragments of the carrier as described above for the individual bearing elements, as a closed sequence, are placed in different groups or as individual packets in a single frequency band, or alternately in the time-frequency space.
When implementing the proposed method many opportunities implementation is the result of razdelimosti separate portions of the signal having a different configuration or sufficiently spaced from each other in the frequency-time domain, including the received multipath components. This tool can be used in a variety of ways. For example, using an appropriate modulation information transmission can be performed with higher speed and/or reliability can be improved parameter definition media. In addition to sharing information signal more or less evenly in the relevant fragments of the carrier may be preferred encoding one with whom mwala in two or more fragments of the carrier, which is the same information. When this becomes possible, for example, to avoid omissions dangerous loss of information, to support correction algorithms data to make markers for signal processing and/or to create a separate fragments as a reference signal for use in processing. In the latter case, if necessary, to completely abandon the information modulation of the corresponding fragment of the signal.
Such a variety of temporal and frequency parameters of signals allows them to use the preferred way for recognition, separation and analysis of signals in a multiple access channel, i.e. in multi-player mode in the specified frequency band.
Sweep or fragments carrier F2 signal preferably configured for a particular Protocol that is installed on the transmitter side and the receiver side. This Protocol may, for example, be different for different pairs of users, thanks mostly in multi-user mode access to the same channel reduces the danger of interfering effect of signals on each other. On the other hand, when using the same configuration of the carrier sweeps in parallel using multiple F2 signals such transfer Protocol can be, for the example, to establish or set of time intervals (time slots) and the appropriate ordering of signals in time. May also be operative adjustment to current conditions of transmission, on special application requirements or wishes of the user. Mutable data transfer protocols can be, for example, with the goal of achieving the best reception quality, efficient use of bandwidth, reducing the waiting time for switching to another frequency band or to reduce the risk of interception or eavesdropping signal, etc.
In one form of the method possible combination with other practices ways, especially with the known method the direct modulation of a carrier signal pseudo-random sequence. For a number of applications, the ability to use multiple modulation together with the direct modulation of a carrier signal pseudo-random sequence or PN-way can provide advantages, for example, to further improve noise immunity during data transfer, the increase in the variety of forms of modulation, bandwidth of the transmitting channel, improving the possibilities of multi-user access, disguise or hide the signals or the messages.
The receiver corresponding to the invention is designed to receive transmitted by the transmitter signals, and for processing and evaluation of their parameters. Processing in accordance with the agreed Protocol or in accordance with the frequency and/or temporal pattern segments of the signal makes possible the selection of the information signal from the received spectrum and in particular targeted the merging portions of the signal distributed in the frequency-time domain. In particular for multiple modulated, for example, modulated according to PN-way, signals mentioned template can be formed from separate parts, which are usually located sequentially in the given order. During the separation and demodulation of various noise components are attenuated or eliminated that from the point of view of information transfer, in General, is evaluated as gains modulation.
The claimed method provides that the F2 signal after receiving the transformed or converted to another frequency form, for example in a continuous frequency band. This is done, for example, by mixing or multiplying the generated reception auxiliary frequency (heterodyne frequency), which has the same law of variation of the frequency as a carrier oscillation transmitted is of igala, however, in parallel shifted towards her so that the frequency of the carrier oscillation of the converted signal has a constant value. Alternatively, the conversion can be done by heterodyne frequency with opposite stroke frequency changes compared to those of the transmitted signal, which can be shifted in parallel or lie in the same frequency band. These options can be combined to handle more complex structures signals, for example for the distribution of transformed signals or components in different spectral ranges. Also the method includes the option of converting the signal at constant frequency in several stages, for example, for iteratively processing results or compensation variable during changes of certain signal components.
The frequency conversion carried out for demodulation sweep carrier, has, along with the dismemberment of multipath components on the narrow-band spectral line, another useful effect. It is that energy components contained in the received signal and distributed in the frequency band, is concentrated in one frequency "cell". At the same time narrow-band noise contained in the received signal, dissipate their energy is distributed in a broad band. Depending on the selected method of expanding the range at this stage there is an increase in the signal-to-noise ratio and thus obtain a system of winnings and winnings from the use of multiple modulation.
When generating the auxiliary frequency, if necessary, are also taken into account the Doppler frequency shifts of the acquired signal in the transmission channel.
After converting the received signal into another frequency form can be further processed in the frequency domain: if necessary, filtering to separate frequencies or cleaned from noise and interference components, and assessment.
The base case involves the selection of one of the spectral lines of the spectrum of the converted signal, in particular, due to multipath propagation, the most suitable for selection and evaluation. Such suitability can be determined on the basis of various criteria, for example based on the circuit configuration. Important selection criteria are, first of all, the power of the corresponding spectral line and/or its distance to the neighboring spectral lines. In many cases, the selected spectral line can be directly evaluated. In one of the embodiments, for example, after separation can be made more films with the walkie-talkie in the time domain, especially by the adaptive filters of the type corrector and/or adaptive correction phase, in particular through fasolada circuit, for example to improve the possibilities for recovery of the transmitted signal and/or conduct a more successful estimation of signal parameters. One of the advantages of the proposed method is that after conversion of the signal at constant frequency ensures compatibility with all known methods of processing, depending on the needs can be shared with virtually any number of individual operations or stages more complex signal processing, filtering methods with direct and feedback, etc. with which almost all the parameters of the signal in time, frequency, and/or any other field of view of the signal can be processed and evaluated.
The analysis is carried out, for example, demodulation fazokodirovannymi F2 signals through the degradation of a received signal on the auxiliary components generated on the receiver side (auxiliary oscillations, the quadrature components, fasolada chain, FFT or bistable circuit), and, for example, is determined by the phase difference between the two, mainly neighboring temporal cycles of modulation.
In one embodiment, the method preduster is provided the ability to select not one, and two or more frequency (multibeam) components of the spectrum of the converted signal, and their subsequent processing mainly in separate channels of signal processing or sequentially in a single processing channel. The results of the processing, for example, different multipath components can be compared or processed collectively. So, for example, such a simple tool, such as the building of the mean value of this parameter signal weighted in accordance with the corresponding power component gives a significant narrowing of the range of scattering of the final result, which reduces errors, and allows the use of more complex modulation methods (e.g., phase modulation with an increased number of discrete States). Thus by applying F2-way effect of multipath propagation can be used with benefit, which is defined as "win, due to multipath propagation".
One of the ways of development of the method contains a variant in which the spectrum of the received transformed signal are two or more spectral lines, and so shifted with respect to each other and are converted by the frequency that the carrier oscillations become coherent, combined, in particular naladiv who are one another or are added, and eventually analyzed. The advantage of this method of processing is primarily in the energy concentration of the signal corresponding fragments in such a way that, ultimately, significantly more powerful signal processing. In addition, there is a more important effect, consisting in the fact that in the same order are summed and noise components, which, however, does not result in a mandatory order to strengthen the result of noise.
Since each multipath component, especially when multipath propagation, carries with it its own component of the noise, with the addition of random noise values of the components of several multipath components of a corresponding alignment of the energy components of the noise spectrum. Of course, you must take into account the real environment using the echo signals as a parallel sequence repeatedly received useful signal, i.e., that the multipath components can be of different quality and, usually taken with different power levels. However, on the basis described here the basic principle that can be extended depending on the application, as well as refined, is achieved on top of a significant improvement in signal-to-noise ratio, is also the win by combining many multipath components.
As a useful property in the described mapping method it is necessary to note the possibility of estimating the spatial-structural and physical properties of the transmit channel obtained and used for calculation of the correction values of the components to achieve their coherence, which in a sense are already well prepared for this purpose. Further processing and evaluation to highlight information such represent one of the feasibility of the proposed method.
One of the options that satisfy the requirements of a wide range of applications, especially for data transmission, is an implementation of the receiving part in a so-called "blind receiver". For this special processing procedure of the signal, which is designated as "signal processing blind" (Engl.: blind signal processing}. In this context, "blind" means no special measures intended for precise time synchronization of transmitter and receiver, in which, however, the receiver without additional measures to establish synchronization automatically recognizes the intended signal and evaluates it.
One of the specific features of the F2-cnoco6a, in addition to automated demodulation sweep carrier is optional, SOS is oasa is that multipath components of the received signal can be fully automatically make coherent, and energy of all multipath components to concentrate in one continuous narrow-band signal, which is then available for evaluation. This basic principle can be performed by various means.
One of the preferred embodiments, which is especially effective can be used with linear frequency modulation sweeps carrier essentially consists of three processing stages, which are then individually or in the complex can build up to any degree of complexity. The basic idea is characterized by the following features: a) display of the received signal at two different auxiliary frequency (sweep) to obtain two separate frequency spectra with internal (relative to range) mirror location of the spectral lines of constant frequency, if necessary, carry out correction of the phase of one or both of the spectra; b) the elimination of the expansion of the delays through the use of functional relationships between shifts propagation time and frequency shifts, if necessary, correction of different frequency and phase distortion for fine synchronization elements in both spectra, and (C) multiplying both SPE the TRS with each other for concentration energy of individual elements of the signal in the same frequency cell of a new center frequency and details of the individual elements in a continuous wave with a new center frequency. After that, the Central frequency is filtered and processed. Further details are explained hereinafter with reference to the drawings.
The above method allows you to maximize the signal-to-noise ratio through the use of multipath propagation. The great advantage is that the transmitted frequency-modulated signal can be reduced at the receiving side to a continuous wave. These are all important prerequisites for increasing data transmission speed, transmission reliability and the like, and can also be used otherwise, for example, in mobile communication to reduce the requirement to transmit power (longer battery life, reducing the harmful effects on the user, and the like). The ability to "blind" processing greatly simplifies the practical implementation of the method. In addition to these major benefits, processing blindly means also certain limitations in terms of waveform, frequency and time parameters. In addition, for example, when phase modulation is necessary to consider that in the multiplication of both spectra, the number of resolvable digital phase States becomes twice smaller. The choice of the method of encoding the information signal, however, should not create problems. In addition, there is always the possibility to synchronize the receiver and transmitter when connection is established by processing blindly, for example, on the fly, and then switch to another mode.
Another embodiment of the method includes steps for configuring, for example, for a formulation of the problem the combinatorial type, for example, in underwater technology, location, and orientation, which are often as important as communication. The proposed method provides a principled decision, which in the present form can be used in various fields of technology signals (including the high-frequency region, laser technology etc). In particular, it is envisaged that the information demodulated by the receiver in accordance with one of the methods mentioned above, creates a copy of the transmitted signal and/or a copy of his conversion and such artificially generated signal, free from all sorts of distortion, interference and other changes that occur in the transmission channel is processed together with the received signal or conversion for qualitative and quantitative assessment of changes in the transmission channel and, consequently, to obtain information about the transmission medium, for example, to determine position and motion parameters, determination of structural-spatial and physical characteristics of the transmission channel, its profile and the contained objects, etc.; i.e. to obtain any kind of information acquired when galom in the process of its distribution channel. This information signal is transferred to the transmitter carrier frequency may, of necessity, either stand out, or be used in assessing, for example, as the token.
For different applications the advantage is that the transmitter and receiver can be adapted for this kind of analysis. In accordance with this transmitting device is performed in such a way that the transmitter receives transferred to them by the signals or their components, reflected by the boundary surfaces or from various objects, and processes them together with the original signal for selecting information on the transmission medium.
In addition, in accordance with the proposed method can include information about the properties and other characteristics of the transmission channel when generating the transmitted signal and/or when it is processed, for example, to improve or Refine the results of the processing and/or analysis, or to extend the capabilities of the method.
The subject invention is also a device for transmitting and receiving information, implement a method of transmitting and receiving information, and a system consisting of a combination of such devices transmit and receive.
The transmitting device comprises at least one generator for generating carrier oscillations with continuous change of frequency and accordingly measures at the one modulator to implement this kind of modulation.
The receiving device is capable of receiving signals from the sweep of the bearing. It contains a reference signal generator for forming at least one auxiliary signal from an artificial auxiliary frequency, at least one mixer for mixing the received signal with the corresponding auxiliary signal, and, optionally, one or more filters and at least one unit of analysis.
The invention has in particular the following advantages. First of all, there is the use of broadband signals by means of frequency-modulated signals, which makes possible the transmission of additional information in addition to the existing narrowband channels using a constant carrier frequency, without causing significant interference to data transmission systems based on the use of permanent carrier frequencies. Through the use of continuously changing frequency F2 signal equalization is achieved noise exposure (averaged over a wide band of frequencies) and the prerequisites for improving the signal-to-noise ratio for signal processing at the receiver side. Modulation of a carrier wave or sweep carrier can occur on the basis of digital or analog encoding, depending on the type of application. At about the existence from the well-known methods of pulse frequency modulation applied here sweep carrier contain in each case binding fragment signal, that makes it possible to use visokogradnya methods of modulation and thereby increase the speed of information transfer.
Are achieved advantages that were disclosed in the international application PCT/DE99/02628 (WO 0011817) for the described signal transmission. Since F2-way provides the highest quality separation of multipath components, it also provides the possibility of their separate use, problems of interference arising from multipath propagation, can be successfully resolved, and can be achieved highest stability values of phase and amplitude. Also included are various possibilities of use the effect of multipath propagation. Particularly significant is the fact that the energy arriving at the receiver delayed multipath components can be concentrated. Achieved in this case, the gain due to multipath propagation can be considered as similar to the antenna gain, which is achieved by simultaneously collect the signal energy from the spaced points, with the difference that it uses multiple receiving a temporal sequence of multipath components (echo). Both approaches can, however, quite successfully be combined. The main feature of the proposed invented the I consists primarily in providing a tool for preferably compact solutions.
High quality signal recognition opens up the possibility of simultaneous execution of more subtle modulation of individual parameters or a group of parameters of the signal data. The user F2-technologies can decide for itself whether it will be transmitted in the form of analog signals or in the form of other suitable modulation curve. Options for modulation of amplitude, phase and/or frequency individually or in certain combinations can be combined so that will be generated discrete States that can be used for digital data transmission. The increase in the number of distinct digital States can be used to increase the speed of data transmission. In addition, additional digital state can be realized due to the possibility of combining various modulation parameters. The digital form of modulation may be used, the preferred way for individual scans, which is favourable for multi-user access mode.
Using presented here F2-way can be achieved uniformly throughout the coverage area of the reception quality, and in particular for the application of mobile receivers and transmitters, can be very useful that through this method eliminates the effects of instability (Zam is Rania and omissions, due to multipath interference.
For some applications it may be useful that F2 signals being sufficiently broadband, weakly affected by external interference. For example, it seems unlikely that all the band a whole can be blocked by interference. Also useful is the fact that the energy (or power spectral density) F2 signals are distributed in a wide frequency range. For the reason that each frequency cell signal spectrum contains a small amount of energy and is active for a very short time, is achieved, on the one hand, the fact that these signals are difficult to intercept (in particular, if the structure of the scanner carrier is unknown or specifications scanner change in the transfer process), and, on the other hand, they interact only weakly with other signals, for example, transmitted at a constant carrier frequency or which is also the F2 signals that have a different, for example, opposite in sign to the gradient of the frequency change (cross-scan and so on). Fundamentally possible to use so-called "channel changing (swiperboy) frequency (F2-channels or S2-channels) in addition to the existing channels with a constant carrier frequency, using a correspondingly wide often the s band. The possibility of combining with other methods of spread spectrum provides a useful embodiments of the method by which the above advantages, as well as the range of application can be further developed.
Additional details and advantages of the invention are explained below with reference to the drawings showing the following:
figa, 1b is an illustration of the changes in the time sweep carrier with linearly increasing () and decreasing (b) the law change frequencies;
figa, 2b - representing oscillations of two sections F2 signal;
figa, 3b are examples of the overlay carrier oscillations:
scan the carrier and the carrier with a constant frequency (a), two sweeps carrier with linearly increasing and decreasing the law of change of frequency (b), which can belong to one or two different information signals;
figa, 4b, 4C is a schematic diagram to illustrate the distribution of the spectral energy density superimposed signal components, as well as its redistribution in accordance with the procedure of signal conversion: changing the frequency of the signal spread spectrum (F2 signal), narrowband interference plus noise (a), an inverse relationship due to the transformation of the signal (b), the converted signal plus noise component after filtering ();
5 - and the lustration division sweep carrier at the time ticks modulation;
6 is an illustration of embodiments of multiple modulation in the formation F2 transmitted signal; for example, 4-position with a shift patadyong information signal, which modulates the chirp support oscillation and filtered.
Fig.7 is an example of a frequency band of several F2 signals;
Fig is an example of temporal ordering of scans bearing F2 signal in one frequency band;
figure 9 - illustration of the allocation of fragments sweep carrier F2 signal in several frequency bands;
figure 10 - illustration of the formation of the auxiliary frequency on the receiving side;
11 is an illustration of the display carrier oscillation on the secondary frequency on the receiving side;
Fig - illustration of the fine structure of the received signal;
figa, 13b is an illustration of spectral components converted by the frequency of a received signal;
figa, 14b is a block diagram of the transmitting device and the receiving device (b) in accordance with the invention;
Fig is a block diagram of a receiving device in accordance with one embodiments of the invention;
Fig 16 is a block diagram of the transmitting device for the formation of F2-signals overlapping in time bearing vibration;
Fig is a block diagram of a receiving device with separate channels for processing;
Fig - the Lok diagram of a receiving device for combined estimation of multipath components;
Fig is a block diagram of a receiving device for combined estimation of multipath components with individual correction phase;
Fig is a block diagram of a receiving device with a proofreader;
Fig is a block diagram of a receiving device for combined estimation of multipath components with individual offsets;
Fig is a block diagram of a receiving device with the processing of the received signal is "blind";
Fig is an illustration of the display of the received signal with one of the echo signal at two different auxiliary frequency for the formation of two mirror-image frequency spectra;
Fig - detailed illustration of a display on the upper auxiliary frequency;
Fig - detailed illustration of a display on the lower auxiliary frequency;
figa, 26b is an illustration of the mirror location of the frequency components in the transformed spectra, as well as correction of temporal shifts through a special filter functions;
figa, 27b is an illustration of the location of the frequency components after their displacement along the time axis;
Fig - illustration of the formation of a continuous oscillation and concentration of the signal energy in the frequency band with the corresponding Central frequency (before filtering the scattered components);
figa, 29b is a block diagram of the transmitting device and the receiving device is VA (b) for PN-modulated signals;
Fig is a block diagram of a receiving device with Doppler compensation;
Fig is a block diagram of a receiving device with a built-in block of spectral analysis, in particular for real-time analysis of multipath structure.
The transmission signals in accordance with the proposed invention is described in relation to the signal generation at the transmitter carrier wave and its modulation), as well as processing and demodulation at the receiving side. Known physical and technical measures and means to form or receive signals to digital information encoding for transmission and reception are not described in detail.
The modulation on the transmission side
On figa and 1b are examples of expansions of the bearing with different frequency gradients separately, which in this simple case are linear functions. On figa and 2b, taking into account figa schematically presented several periods of oscillations with a constant value of the frequency gradient, where, however, the value of the initial phase differs by 180 degrees. Set the initial phase is an example of a phase encoding F2 signals. Other encoding capabilities are based on known methods of amplitude and frequency modulation, or a combination of various modulation methods.
Figa and 3b represent the simultaneous transmission scans bearing together with the bearing vibrations, configured in another way, while figure 4, on the basis of a schematic representation of the spectral energy distribution shows that, for example, the F2 signal and a narrowband signal (here the interfering signal with respect to changing the frequency of the signal) affect each other only to a small extent. While the narrowband component is explicitly expressed in the composition of the transmitted and received signals, the energy of the F2 signal, however, is distributed in a broad band (figa), but the relationship between them changes as a result of the conversion of the signal after processing the received signal through an auxiliary variable frequency signal generated on the receiving side (fig.4b). The resulting energy of the original narrow-band signal-to-noise is distributed over the frequency range, while the energy of the F2 signal is concentrated in one frequency cell, however, he becomes much more pronounced clearly above the noise level. This makes it far easier filtering and processing (analysis). Figs is the fact that in the filtered signal still contains a noise component, which can lead to error in the estimate of the transmitted information.
In addition, it should be noted that the imposition of one scanner to another with the opposite gradient (not represented here), p and the transformation of the first constant frequency, the signal energy of the second sweep is distributed over an even wider range of frequencies.
Scan the carrier may be a carrier of one or more bits or (if analog information processing) may contain one or more units of information. For multiple bits or pieces of information scan the carrier is divided into several time cycles of modulation, for example, that illustrated in figure 5. Unit scanner with a linear frequency gradient on two bars of equal duration T1 and T2 are presented in each case, the durations of the cycles tT1and tT2. By subdivision developments bearing on two or more cycles of the modulation can be provided to increase the speed of data transfer.
The unit of time ticks modulation is particularly useful for the transmission of digital information, the split bit streams, recognition. For example, when two transmission zeros, one after the other, they can be spread as individual bits using time cycles of modulation. When using a large number of cycles (for example, 10 to scan) provided a particularly high bit rate.
The introduction of cycles of modulation represents an important distinctive feature compared with the above use of frequency modulation DL the data in other ways. In accordance with the proposed method, the sweep frequency is not just "included" and "off", and potato modulated.
Depending on the application, the time cycles of the modulation with respect to the frequency carrier wave may be changed continuously or stepwise. Under the assumption that for demodulation F2 signal need only a certain number of periods of oscillations of carrier wave. Because the scans is the number of oscillations per unit time is continuously changing, a significant increase in the speed of data transfer can be achieved through the fact that the duration of a quantum modulation is reduced to minimum required values, i.e. consistent with the current value of the frequency variable frequency carrier wave.
A further possibility to increase the data transfer rate is, in addition, the use of more complex modulation methods for encoding information. 6 illustrates the possibility of using multiple modulation in the formation of the F2 signal on the example of one of the known methods 4-position phase-encoded with an offset information signal further modulated by changing the frequency of the carrier; this is only a transmitted signal. Extra sideband filtered. In this representation, the information signal has the property is built is the carrier frequency, which then modulates or is modulated by changing the frequency of the signal; the result in both cases is the same. In the proposed method, however, as was already mentioned above, it is preferable to use a variable frequency signal as a carrier wave for the entire signal. In this regard must, however, be pointed out again that the formation of F2-signals does not imply mandatory that the information signal has its own carrier frequency. It is quite possible option is the direct modulation of the variable on the carrier frequency of the information signal. For this reason, five, 6C to 6E can be omitted from consideration.
Fig.7 shows an example of multiple (simultaneous) use of the frequency band F2 signals having a different configuration. Both the bold lines represent the scan belonging to the same signal that is transmitted at time intervals tw. Sweep belonging to other signals have intervals offset ts(time slots).
In accordance with the invention, scanner F2 signals can be configured for a particular Protocol, agreed to use as the receiver and transmitter. In General, the Protocol is defined that represents the scan (frequency-time function) and how it was soap is determined by the frequency bands. Protocols may be different for each pair of users, in particular, to reduce the risk of impact signals to each other, located in the same frequency band. If many are used in parallel F2 signals have the same configuration, the data transfer Protocol may be, for example, to ensure that through the introduction or specify time Windows or offsets (time slots) achieved their favorable location (see example 7).
May also be prescribed scenario where the Protocol changes its content during transmission of data according to the agreed plan or in accordance with the transmitted encoded signal (send command "transition from Protocol 1 to Protocol 10" and so on).
The next opportunity to prevent accidental overlays several F2 signals consists in the introduction of unequal intervals between scans. Fig is an example of a pseudo-random location of scans in the same frequency band (random mixing time). Dashed lines indicate the expected location of the corresponding expansions in the case of uniform distribution in time. Introduction pseudo-random intervals has the advantage that even without setting specific time Windows (time slots), i.e. in case of accidental mixing signal the time in multiplayer mode access practically no complete overlap of the two or more signals belonging to different users. The imposition of individual scans compensated by appropriate correction algorithms.
Fig.9 shows an example of a transmission Protocol in which fragments of the scanner carrier one information signal is distributed to two different, mainly adjacent bands Δfaand Δfb. Is the alternate switching of the two different channels or bands without changing the frequency characteristic of the gradient.
Demodulation on the receiving side
In accordance with the invention, the demodulation sweep carrier on the receive side is on the same principle, which is described in PCT/DE99/02628 (WO 0011817). The following is only a conversion of the information signal in a band of constant frequency, for example by mixing or multiplying with the auxiliary frequency (sweep heterodyne frequency). Additional well-known activities are intended to improve the signal-to-noise and bandpass filtering.
Figure 10 in the upper part schematically represents the result of the reception of signals in one frequency band that is often used for simultaneous multi-user access to the channel. Thus F2 is a signal intended for the receiver definitely, is indicated by a bold line, and a time window, where at this time is the analyzed signal, indicated by vertical dashed lines. Line in tones of grey belong to someone else F2-signals. On the receiver side is formed of the auxiliary oscillation (auxiliary variable frequency heterodyne signal or signal), which in the same time window tsweephas the same frequency gradient Δfhetthat and the corresponding analyzed scan carrier, differing, however, the value of the initial frequency, for example, as shown in the lower part of figure 10.
Then mixing or multiplication accept changing the frequency of the signal with the auxiliary heterodyne signal. The result is illustrated by figure 11, with the upper part similar to the original configuration, as in figure 10. By displaying the analyzed scan auxiliary heterodyne signal through a mixer or multiplier bearing signals are all located in this time window scan converted fixed frequencies, which now differ only in height constant frequency (lower part of figure 11). From this range, for example, by using a bandpass filter filters the necessary components, in this case converted in frequency by changing the frequency of the signal is al. When this is filtered and appears when the conversion signal side band (not shown here). Converted in this way and "cleaned" by changing the frequency of the signal can then be processed as a normal signal with a constant carrier frequency by attracting well-known in the practice of signal processing methods allocation information parameters, such as phase angle, amplitude, or, as in the case of frequency modulation, remaining after the signal conversion, the law of variation of the frequency or nature of the phase change. A significant advantage of F2-technology is the ability to get full compatibility with other known methods of signal processing simply by running one intermediate stage frequency conversion.
In addition, F2 is the method also includes the analysis of Doppler shifts, for example, on the basis of the variances in the values of the converted carrier frequency from the expected value, for example, to assess the rate of change of the distance between the transmitter and receiver, or for taking in the other calculations obtained by Doppler shifts in the formation of the auxiliary variable frequency signal to improve the quality and stability of communication. This embodiment has advantages in particular DL is the link between fast-moving objects. Also here it is necessary to indicate the possibility of obtaining data on the transmission medium from the analysis of the received signals.
Another advantage of the invention lies in the fact that in the described conversion of the received signal by the auxiliary signal, in the case of multipath propagation possible selection and analysis of many multipath components of one or more suitable, for example, the most powerful multipath component, for example, using respectively notch filters or the corresponding FFT analysis. On Fig and 13 (similar to figure 10 and 11) provide a detailed view, on the basis of which explains the features of the way, giving a new quality of data especially in heterogeneous and structured environments.
In General provides for the allocation of the spectrum of the converted signal separate, the most suitable for the processing of spectral lines (feedback channel), for example, the most powerful, is contained in the spectrum due to multipath propagation and evaluation, preferably by filtering devices or on the basis of simple or complex FFT analysis.
In the case of multipath propagation continuous frequency change caused by the effect that some megol the key components arrive at the receiver as shifted in time parallel variable frequency signals. In addition to differences in propagation time, the degree of a parallel shift in the time-frequency plane is also determined by the frequency gradient expansions. Frequency gradients determine the effect that shifts in time, i.e. differences in the time distribution of the different responses of the channel, exclude the interference of multipath components and due to the different values of their frequencies can be separated by using the signal-technical means and their mutual influence is weakened. The steeper the pitch, i.e. higher frequency gradient within a given portion of the signal, the wider the spectrum decoding of multipath components.
This makes it possible to adjust the method to different communication conditions, and, for example, when transmitting data over the air inside buildings, the city or outside the city apply situational-dependent different frequency gradients, i.e. apply sweep bearing with different slopes.
Fig represents a sequence of multipath response (marked as R1-R5), which come with different time delays (denoted as tcrdto delay the distribution channel in the form of parallel scans. Consequently, expanding the time window for the reception of different copies of the same change is eghosa frequency signal by an amount t sd(delay time distribution). Figa schematically shows that in the frequency conversion corresponding differences in propagation time seem different spectral lines in the spectrum. Here enters into force, the effect is already explained on the basis of figure 4 that by converting the signal energy, in its original form distributed in the frequency range ΔF, is concentrated in one frequency cell (fig.13b), it achieves a significant improvement in signal-to-noise ratio and, together with this, softens the effect of random noise components.
Despite a noticeable improvement, converted multipath components, depending on their background in the transfer process, however, may have a different capacity, as it was shown in example fig.13b. The first is technically just implemented the selection criterion is the determination of the frequency having the greatest amplitude, with its subsequent filtering, for example, through a controlled, relatively narrow-band filters. The corresponding configuration of the filter may be, for example, in analog form, as described in PCT/DE99/02628 (WO 0011817). Similarly, the placement of desirable components in the specified band of the filter is possible by changing the initial values of the auxiliary frequency. With p the power of one of these measures can be achieved in each case, the best signal-to-noise ratio. On the other hand, for example, applying a phase encoding can be useful option selection from the spectrum of the constant intermediate frequency (if one preferred, if possible, separately located multipath component, because it is the phase of the neighboring components of the spectrum have an even smaller impact.
In this regard, it should be noted, in particular, through the use of a sufficiently large frequency gradients to sweep the carrier signal can be separated from each other including those multipath components, the difference in propagation time which leads to a difference in phase πbut their mutual compensation due to interference can be excluded with high reliability.
The identification of specific frequencies contained in the converted signal in accordance with fig.13b, can further improve the signal-to-noise ratio. All separate frequencies are the same useful information along with various noise components corresponding to different geometric ratios for the transmission channels. Thus, there emerges a useful redundancy. In each case, two or more components (feedback channel) are selected and separately analyzed. Then the results of the analysis are compared or obrabatyvalis is together, for example, through education averaged values of the corresponding parameter of the signal, if necessary, weighing these results are in accordance with the power components. This means that the natural redundancy, due to multipath propagation, i.e. the appearance of multiple copies of the signal (feedback channel) from the same information signal, which is the main problem during data transfer, can be used beneficially to improve the quality of the results of processing the received signal. Despite the improvement in signal/noise and partial alignment of the noise component at a known frequency band, under the influence of the noise can still be a random scattering phase, especially when using short cycles of time. In the technique of signal processing for such a case, usually, use longer cycles of modulation to provide averaging in time. In F2-technology, however, may additionally be used in a natural way due to a parallel set of multipath components (echo), and the parameter of the signal carrying the information is evaluated in the process of simultaneous parallel processing of many such components, processing results which are then used appropriately shared./p>
Various possibilities of achieving synchronization for simultaneous processing of components of the special techniques and then combining the energy of these components on the same frequency to obtain respectively amplified signal and its subsequent evaluation described above.
On Fig-28 present a method of signal processing "blindly". Presents an example corresponding to the invention, a processing method in which a received signal which is schematically represented in the form of two multipath components, each separated in time τfirst, is multiplied by the first auxiliary heterodyne frequency lying in the band of higher frequencies, and secondly, is multiplied by another heterodyne frequency, which has the same frequency characteristics as the first, but compared to it lies in the lower band of frequencies. Fig shows that the two auxiliary frequencies are generated simultaneously, however, they need not be synchronized with the received signal. The duration of the sweep Tswit is, however, in all cases the same. The arrow marked Δω with relevant indices, represent the instantaneous ratio between the frequencies, which are formed due to the random time offset between the multipath components of the received signal and the auxiliary change is engaged by the frequency signals.
Fig and 25 are respective parts in detail. Fig provides a detailed view of the display on the upper auxiliary frequency and Fig provides a detailed view of the display on the bottom of the auxiliary frequency. In this regard, if necessary, can be phase transformation of one or both of the spectra. Figa and 26b schematically represents both the spectrum obtained after multiplication with the corresponding auxiliary frequencies. In these spectra the individual spectral components are mirrored in relation to the center frequency of the corresponding spectrum (here are in both cases as Δω). If the center frequency of the auxiliary signal with changing frequency (heterodyne frequency) is not symmetric with respect to the received signal, the center frequency of both spectra can also vary. Important are only the mirror-symmetric ratio in these spectra. In the right part of the graphs is a schematic representation of a filtering function, by which the adjusted time shifts of spectral components. At this stage of processing may, optionally, additionally be used to adjust the individual frequency and phase distortion to provide fine synchronization elements in both SPECT the Ah. On figa and 27b schematically represented by analogy with Figo and 26b, the position of the frequency components after the shift along the time axis. If presented on figa and 27b spectra of multiply, synchronized before these elements will be combined in the form of a continuous wave having a frequency of 2Δωand the signal energy will concentrate in the corresponding frequency window. Fig schematically shows the result of this operation. The new value of the Central frequency (shown in bold line) can now be filtered and evaluated.
The transmitting and receiving device
Fig is relevant to the invention the transmitting device 10, having in its composition generator 11 for generating a gradient carrier wave, a modulator 12 for modulating the carrier wave, and the mixer 13. The generator 11 is designed to generate a gradient carrier oscillations or scan the carrier in accordance with the above principles, and can optionally use known in the art managed shapers signals. The modulator 12 is designed to encode the transmitted information. Modulation is performed in accordance with one of the methods known in the art of encoding information. The mixer 13 is a module for mixing the carrier and information component (mixer, paramn the resident and the like). This mixer has an output 14 is connected, if necessary, through a filter 15, or directly through the transmitter with the physical transmission channel. The filter 15 is preferably in the form of a bandpass filter (PF) and can be switched between the output 14 and the transmitting antenna or the transmitting transducer (not shown). The filter 15 is designed to address emerging lateral frequencies. If they do not create interference, the device can be connected directly to the output.
In this transmission system, the information transmitted (the character) is converted to the modulator 12 and then in the mixer 13 is transferred to the support gradient oscillation generated by the generator 11 connected to the mixer. The switch 16 and the band-pass filter, denoted by a dashed line indicate that the filter 15 may be additionally included in the circuit in series with the mixer.
Fig.14b is one of the forms of carrying out of the invention the receiving device 20 having the generator 21 for generating an auxiliary frequency, preferably a gradient or fluctuating signal with changing frequency, the device 22 display to overlay the received signal from the receiving antenna or the receiving transducer (not shown), such gradient oscillations or signals with changing the hours of the Sabbath. Auteuil, the device 23 for separating signal components and the demodulator 24. Circuits 21-24 form a device for receiving signals with changing carrier frequencies.
The generator 21 can optionally use known in the art signal processing managed shapers signals. The device 22 of the display contains a mixer, multiplier, etc. Device 23 for separating signal components comprises at least one module for separating signal components such as bandpass filter, the managed device filtering or FFT filter. The demodulator 24 is suitable for analysis/demodulation signal and outputs a transmitted information symbol. When using a complex FFT module as an analysis device a device for the separation of the signal and the demodulation device may be implemented as a combined schema.
Fig fragmentary represents the execution of a receiving device, which performs target processing one multipath component.
The following embodiments of the receiving and transmitting devices have advantages, especially in multi-user mode access. Fig and 17 are examples in which there are many parallel channels for forming and signal processing, and are appropriate to eastwoodiae modulators and generators are included mainly in parallel and are combined with each other via a Central control module (not shown), which controls the shape, the height position and the interim order of the expansions of the carrier frequency and/or modulation (preferably in accordance with the transfer Protocol). Accordingly, the receiving device may also comprise a control module, which in turn controls the signal processing. If necessary, many of the schemes listed on figa, 14b and 15 are included in parallel and are combined by a common control module and are complemented by other elements in the schema.
On Fig presents a block diagram of a receiving device for combined estimation of multipath components, and unit τ designated group of items correction of distortions or shifts, such as time shifts. As a further development of the options presented on Fig, Fig presents a block diagram of a fragment of a receiving device, designed for combined estimation of many multipath components with individual correction phase.
Fig is a block diagram of a channel processing of the receiving device is supplemented by a nonlinear filter for the correction of a single multipath component. Considering Fig, Fig represents an embodiment that provides a combined processing of multipath components and having in its composition elements and therefore the s for individual precise correction.
Fig is the example of the Central part of the receiving device for carrying out the above-mentioned signal processing "blindly". Fig-31 are other ways to perform their invention of devices, intended for implementation in conjunction with the above PSH-way and taking into account the Doppler shift.
The application of the invention is not limited to certain media content, encoding, modes of transmission and a transmission medium. For example, there is a possibility of application of the method for acoustic data transmission, for example by means of acoustic waves through the air (control of electronic devices, acoustic mouse, keyboard, etc) or other gaseous, liquid or solid medium, such as water, through solid objects, or waveguides. As other applications, you can specify the telecommunication, data transmission through laser beams, electrical or optical cable, remote control (TV, keyboard) or control under water, as well as joint or separate use to transfer information and/or to determine environmental parameters.
The features of the invention described in the description, drawings and claims can be used in Atsa separately and in any combination for realizing the invention in its numerous forms of execution.
1. Method of transmitting and receiving information through the waves, comprising the steps of: matching the frequency response sweeps bearing against the provisions of frequency, slope and/or shape change of the carrier frequency from the scanner to scan a variable manner in accordance with the terms of the transmission channel or mode of access to the transmission channel, the overlay information signal onto a carrier wave, the frequency of which is continuously and smoothly changes to a given time interval to construct a sequence consisting of at least two carrier sweeps, each sweep carrier carries one or more units of information, or bits, transmission of the generated signal does not contain in its composition the reference component, filtering the received signal or cleaning of the received signal from noise in the frequency domain to separate multipath components and evaluation of the received signal parameters that carry information.
2. The method according to claim 1, characterized in that the information signal is a wave, modulated analogue or digital by changing the values of the individual signal parameters or combinations of parameters in the form of phase modulation and/or amplitude of the modulation, and/or frequency modulation, independent of the frequency characteristics of the carrier wave.
3. The method according to claim 1, characterized in that the sweep of the bearing are separated by time and distance between scans bearing are the same or changing.
4. The method according to claim 3, characterized in that the transmission of the position of the frequency sweeps of bearing change by switching to other bands.
5. The method according to any one of claims 1 to 4, characterized in that the sweep of the bearing are divided respectively into N time quanta modulation with a specific modulation of the information signal, where N is a positive integer greater than 1.
6. The method according to claim 5, characterized in that the duration of cycles of modulation change depending on the frequency of the carrier wave continuously or discretely.
7. The method according to claim 3, wherein the information code in the form of relative changes of parameters of the signal between two different, especially between adjacent time intervals or cycles.
8. The method according to claim 3, characterized in that a specified band of frequencies passed many of the modulated sweep carrier, which may overlap in time, and these bearing sweep belong to the same or different information signals.
9. The method according to claim 8, characterized in that chosen to replace the th wave is divided into two or more parcels with different frequency characteristics, which overlap in time or are transmitted simultaneously, and at least one of these sections is formed in the form of a sweep carrier, transmit mentioned, at least one of the parts in combination with plot with a constant carrier frequency and/or with one or more sweeps of the bearing with the other, mostly opposite, frequency gradient and/or other form of scanner, and many of the plots encode one character or carry the same information, and/or at least one of these areas can be used as a reference signal, preferably in this part carry out uniform modulation or generally exclude any kind of modulation in terms of information transfer.
10. The method according to claim 8, characterized in that in a given frequency band simultaneously transmit two or more modulated sweeps bearing with different temporal and/or frequency response, as well as in conjunction with one or more carrier waves of constant frequency, which belong to different information signals.
11. The method according to claim 8, characterized in that the initial configuration of the scan load-bearing or load-bearing waves or their ordering in one or more frequency bands set in the form of a Protocol, which may become relevant Ave is in the process of information transmission between the receiver and the transmitter defined in a consistent manner, or based on the transmitted information.
12. The method according to claim 8, characterized in that the information signal, and/or a carrier wave, and/or transmitted signal entirely Peremohy for transmission with a predetermined or agreed in the transfer Protocol psevdochumoy (PN) sequence.
13. The method according to claim 8, characterized in that the wave form in the form of sound waves or electromagnetic waves.
14. The method according to claim 8, characterized in that the components belonging to a given information signal extracted from the received signal in accordance with a time and/or frequency pattern, specified or agreed in the transfer Protocol.
15. The method according to item 12, characterized in that after taking on one of the processing steps perform the multiplication of the signal with the PN sequence.
16. The method according to item 13, wherein after reception signal is converted into a different frequency form.
17. The method according to item 16, wherein after receiving the conversion signal to another frequency form carried out by mixing or multiplying the received signal with the generated heterodyne signal having the same law of variation of the frequency as the carrier wave of the transmitted signal, but preferably shifted in parallel so that the frequency of the carrier wave of the converted signal is constant or frequency is leaving the corresponding spectrum are constant frequency.
18. The method according to item 16, wherein after receiving the conversion signal to another frequency form carried out by mixing or multiplying the received signal with the generated heterodyne signal with the sign of the gradient of the frequency, the opposite sign of the gradient of the frequency of the carrier wave of the transmitted signal, so the frequency of the carrier wave of the converted signal is constant or frequency components of the corresponding spectrum are constant frequency.
19. The method according to 17 or 18, characterized in that to determine the Doppler frequency shift of the received signal and keep in mind when forming the heterodyne signal.
20. The method according to 17 or 18, characterized in that separate from the spectrum of frequencies contained in the converted signal, in particular due to multipath propagation, correspondingly the most appropriate, especially the most powerful of acceptable frequency components, and, if necessary, subjected to additional filtering in the time domain, in particular by means of an adaptive filter, for example, equalizer, and/or adaptive devices for the correction phase, especially fasolada chain.
21. The method according to 17 or 18, characterized in that the separate frequencies processed through the filters and/or on the Nove simple or complex analysis by fast Fourier transform (FFT), and/or the signal parameters that are relevant for the information encoding is determined on the basis of decomposition on the sine and cosine of the reference oscillation, and/or by way of samples.
22. The method according to 17 or 18, characterized in that separate from the spectrum of frequencies contained in the converted signal, there are two or more frequency components, analyze them separately and results are compared or converted, in particular through the formation averaged over the relevant parameters of the signal values, if necessary, with weighting in accordance with the capacities of the relevant components.
23. The method according to 17 or 18, characterized in that separate from the spectrum of frequencies contained in the converted signal, there are two or more frequency components, shifting one relative to another and convert frequency to carrier waves were coherent, and then process them together, in particular by imposing on one another and build, and evaluate, and received or considered, the correction parameters contain information about the spatial-structural and physical properties of the transmission channel, which may be subject to separate analysis.
24. The method according to item 16, wherein after receiving the carry signal processing with automatic is a mere recognition signal, and
A1) the received signal on two separate, for example, parallel stages Peremohy with the generated reception heterodyne signal in accordance with any of PP and 18 lying in a higher frequency band, and Peremohy with other heterodyne signal, which is compared with the first heterodyne signal is either identical or opposite in sign to the frequency gradient, but lies in a lower frequency band, so that there are two spectra of the converted signal, in which frequency components are mirrored relative to the Central frequency of each of the spectra, or
A2) by multiplication with only one formed in accordance with any of PP-18 heterodyne signal, lying either in a higher or lower frequency band, formed from a first spectrum of the converted signal, from which then, by multiplication with a constant higher or lower heterodyne frequency, form the second range with internal mirror spaced frequency components, and
B) in both spectra corresponding spectral components synchronize with the frequency-dependent functions of time, in particular filters with non-linear phase characteristics, with supplementary performance, if necessary, adjusting the AI phase to achieve coherence, and
C) Peremohy both spectrum with each other so that the individual components transform in a continuous wave of a certain frequency, combining the main part of the signal energy and have the ability to filter in the frequency domain and analysis.
25. The method according to 17 or 18, characterized in that by means of demodulation at the receiving side restores the transmitted signal or the converted transmitted signal and the resulting signal is processed together with the received signal and/or the intermediate processed received signal to obtain information about the environment, in particular for determining the position and motion parameters, to obtain information about the spatial-structural and physical properties of the transmission channel, including information about its profile and its inhomogeneities, on the basis of changes in the signal during its propagation in the transmission channel.
26. The method according to item 13, wherein the transmitter receives diffracted from channel or contained inhomogeneities copies or multipath components of the transmitted signal and processes them together with the original transmitted signal for highlighting information about the environment.
27. The method according to p, characterized in that information about sootvetstvuyushchaya and other characteristics of the transmission channel into account when forming the signal and/or signal processing.
28. The transmitting device (10) for transmitting waves carrying information, in accordance with the method according to any one of claims 1 to 27, containing at least one generator (11) for the formation of the carrier waves, at least one continuous and smooth change in frequency, which is a scan of the carrier, the modulator (12) to form or encoding the information signal, the mixing device (13) for modulation of the carrier wave information signal and connected therewith, the transmitting transducer, and, if necessary, the filtering device (15)connected between the mixing device and transmitting Converter, made in the form of a bandpass filter.
29. The transmitting device according to p, characterized in that it comprises a control module to control the shape, height, time sequence of scans bearing and/or modulation of the information signal.
30. The transmitting device according to any one of p-29, characterized in that it contains a group of generators, modulators and/or mixing devices, connected in parallel, connected to each other via a Central module to control the shape, height and time sequence of expansions of the bearing, and further comprises a delay line in the circuit for a specified group of generators, modulators and/or mixes the existing devices, and blend, made in the form of an adder in the circuit after the specified delay line.
31. The transmitting device according to item 30, characterized in that it contains an additional device modulation sweep carrier signal pseudo-random sequence, one in the chain sweep carrier signal.
32. The receiving device (20) for receiving a signal wave, carrying information transmitted by the method according to any one of claims 1 to 27, containing United host the Converter and the generator for the formation of the auxiliary oscillations, which has the same law of variation of the frequency as a carrier oscillation of the transmitted signal, but shifted in parallel with respect thereto so that the frequency of the carrier oscillation of the converted signal has a constant value when the generator consistently included conversion device made in the form of a multiplier for multiplying the generated auxiliary oscillations with the received signal, after which the device for separating signal components in the frequency domain followed by a demodulator and/or a device for analysis of the parameters.
33. The receiving device according to p, characterized in that it contains two or more connected in parallel channels, each of Kotor is x consists of the conversion device, followed by a device for separating signal components, followed by a demodulator and/or analysis device settings, United by a Central control module that controls the signal processing in accordance with the transfer Protocol.
34. The receiving device according to p, characterized in that it contains working in the time domain adaptive filter unit connected between the device for separating signal components and a demodulator and/or the unit of analysis parameters, and/or adaptive device for correcting phase included after the device for separating signal components.
35. The receiving device according to p, characterized in that it further comprises a device for analysis of frequency spectra, designed to make settings that are included in the chain directly after conversion device.
36. The receiving device according to p, characterized in that after the device for separating signal components includes one or more devices additional filtering in the time domain, in particular through the adaptive filters of the offset and/or adaptive correction phase, followed by a mixer and filtering device.
37. The receiving device according to p, characterized in that the circuit device is istwa to separate signal components includes an additional device, comprising at least one generator PN sequence and is connected to it in series, at least one multiplier.
38. The receiving device according to p, characterized in that it contains additional processing module for determining based on the received signal components of the environmental parameters by comparing the received signal with the generated internal reference signal.
39. System for transmitting information comprising at least one transmitting device (10)made in accordance with any of p-31, and at least one receiving device (20)in accordance with any of p-38.
FIELD: radio engineering.
SUBSTANCE: in accordance to method, transmission and/or receipt of information are performed by means of waves, in accordance to which superposition of information signal over carrying wave is performed, frequency of which wave changes continuously and smoothly on given time interval for generation of at least one scanning of bearing, while signal being transmitted after receipt is filtered in frequency area for separation of multi-beam components or cleared from interference and then estimated relatively to signaling parameter, carrying information.
EFFECT: increased data transmission quality, increased resistance to interference.
4 cl, 41 dwg
SUBSTANCE: invention may be used for generation of frequency-modulated signals in networks and communication systems. Frequency modulator comprises source of reference voltage, integrator with reset, comparison unit, time digitiser, memorising unit, counter, generator of Walsh functions, multiplier, generator of rectangular pulses, element NOT and switch.
EFFECT: increased efficiency of frequency band application.
4 dwg, 1 tbl
FIELD: physics; radio.
SUBSTANCE: present invention relates to wireless communication and can be used for transmitting discrete messages through phase modulation of carrier frequency using pseudorandom sequences. On the transmitting side the device contains a source of discrete messages, six multipliers, a pseudorandom sequence generator, an adder, a power amplifier, carrier frequency oscillator, non-systematic division unit and an Adamar-Walsh sequence generator. On the receiving side, the device contains an amplifier, first band-pass filter unit, second band-pass filter unit, a multiplier and a demodulator.
EFFECT: more efficient use of the spectrum and increased noise immunity with simplification of the receiving part at the same time.
FIELD: physics; radio.
SUBSTANCE: present invention relates to wireless communication and can be used for transmitting discrete messages through phase modulation of carrier frequencies using pseudorandom sequences. On the transmitting side the device contains a source of discrete messages, a unit for non-systematic division, four multipliers, pseudorandom sequence generator, carrier frequency generator, an adder and a power amplifier. On the receiving side, the device contains an amplifier, multiplier, three band-pass filters, a collector, demodulator, pseudorandom sequence generator and a search and synchronisation unit.
EFFECT: increased noise immunity.
FIELD: physics; radio.
SUBSTANCE: present invention relates to wireless communication and can be used for transmitting discrete messages using signals with direct spectrum broadening. On the transmitting side, the device contains a source of discrete messages, a unit for non-systematic division, first pseudorandom sequence generator, Adamer-Walsh function generator, carrier frequency generator, clock frequency generator, six multipliers, 90° phase shifter, an adder and a power amplifier. On the receiving side the device contains an amplifier, synchronisation unit, three band-pass filter units, 90° phase shifter, pseudorandom sequence generator, five multipliers, carrier frequency generator and a demodulator.
EFFECT: increased message transmission rate and structural security of the device for transmitting and receiving discrete messages using signals with direct spectrum broadening, with invariance properties to frequency-phase perturbations, arising in a communication channel.
FIELD: physics; radio.
SUBSTANCE: present invention relates to radio engineering and can be used in information transmission systems. The method is characterised by that, there is periodic generation of quadrature and in-phase components of the composite signal, from which, depending on the bit sequence of the information sequence, modulation code sequences for sin and cosine channels are generated. Received sequences are converted into a bipolar code and quadrature components of the sub-carrier frequency are phase modulated. Phase modulated oscillations at sub-carrier frequency transmitted to the quadrature modulator of carrier frequency, the output signals of which are added.
EFFECT: increased noise immunity of transmitting binary information using composite signals.
5 cl, 1 dwg, 1 tbl
FIELD: physics; communication.
SUBSTANCE: present invention relates to a method and device for transmitting data between a switch and a terminal and can be used for transmitting data between a switch and a terminal in bidirectional frequency keying (FK) mode. The device has a frequency keying module for creating a first packet of frequency keyed data and transmission of this packet, and also for syntax analysis of service data of the second packet of frequency keyed data, a module for receiving/transmitting and modulating/demodulating the first packet of frequency keyed data in frequency keyed mode after receiving the first packet of frequency keyed data from the frequency keying module and for outputting the modulated first packet of frequency keyed data as well as for demodulating the second packet of frequency keyed data after receiving the second packet of frequency keyed data for transmission of the demolated second packet of frequency keyed data to the frequency keying module.
EFFECT: faster transmission of information between a switch and a terminal.
12 cl, 8 dwg, 3 tbl
FIELD: physics; communications.
SUBSTANCE: invention relates to high-speed devices for demodulating signals with double phase modulation and can be used in communication systems for various purposes (satellite, cable, radio relay etc) with the aim of increasing efficiency of the demodulator in conditions of large mismatch of frequency of the input and reference signals. The demodulator for a communication system with double phase modulation comprises a first, second, third and fourth multipliers, first, second, third and fourth lowpass filters, first and second limiters, subtracting unit, first and second adders, loop filter, switch, saw-tooth voltage generator, frequency controlled generator, quarter phase changer, first and second squaring devices, first and second comparators, beat signal level detector, high-pass filter and logic analyser.
EFFECT: simpler and more stable operation of the device, wider range of rates of received data in the low frequency region, prevention of false capturing and improved dynamic properties the loop of tracking the demodulator.
4 dwg, 1 tbl
FIELD: physics; communications.
SUBSTANCE: invention relates to transmission and reception devices which correct data errors in a communication channel. In the transmission device, the unit for adding redundancy bits adds the redundancy bit to each bit of data received using a single bid divider; and a multiplier executes multiplication. The transmission device transmits a frequency modulated (FM) signal modulated by a frequency modulation unit. In the reception device, a character recognition unit recognises the character at the Nyquist point for the signal which is demodulated by the unit for demodulating the FM-signal; a bit conversion unit converts bits in accordance with the character recognition result; and a frame reconstruction unit removes the redundancy bit, added by the unit for adding redundancy bits of the transmission device, from the bit string deinterleaved by a deinterleaver.
EFFECT: correction of errors using simple configuration, even during communication in an unfavourable medium.
15 cl, 8 dwg
FIELD: physics; radio.
SUBSTANCE: invention relates to radio communication. When a sound presence/absence detector detects a silent interval, a modulated carrier signal is output in the region used for transmitting speech data which are contained in transmission data, having a frame structure and which correspond to the silent interval. In other words, a frequency-shift keying (FSK) modulator initiates output by the transmission circuit of unmodulated carrier signal from the radio communication device to the region used for transmitting speech data corresponding to the silent interval. Meanwhile, a wave signal modulated by FSK with four levels is output in regions different from the silent interval. In the region of channel identification information contained in transmission data with frame structure, there are distinguishing data for absence of modulation to made possible determination of the silent interval, and the distinguishing data enable the communication terminal device at the receiving end to avoid any unstable operations.
EFFECT: communication channel bandwidth reduction and reduced effect on adjacent channels.
6 cl, 7 dwg