The use of orthogonal signals to provide for joint use of multiple transmitters channel multiplex transmission code division

 

The invention relates to communication systems, spread spectrum, providing the opportunity for multiple transmitters to share a single channel multiplex transmission code division (MPCR) or channel multiple access code division (mdcr) by using these channels orthogonal transmitted signals. Generates a set of orthogonal code channels Wi(t), and each transmitter in a predefined manner are allocated orthogonal codes for channel and polynomials pseudotumor code. Transmitters form for each information signal channel using orthogonal code Wi(t) and produce expansion of the spectrum of each of the information signal using pseudotumor code spread spectrum. Each transmitter uses the same pseudosolenia codes expand the range and timing offset. Neither one code channel is not assigned to more than one transmitter, when these transmitters share a channel with MPCR. Signals spread spectrum are summarized in each transmitter in the form of a single composite signal prior to transmission. Offset pre-adjusted time to time is now aligned in the receiving device. 5 C. and 25 C.p. f-crystals, 7 ill., table 1.

The present invention relates to communication systems, spread spectrum and, in particular, to systems that provide multiple transmitters opportunities to share the channel multiplex transmission code division (MPCR) or channel multiple access code division (mdcr), as a shared resource in such systems.

In TDM systems with code division (MPCR) signals intended for one or more recipients, are transmitted from one station using a single frequency band or channel MPCR by the allocation of codes to generate a code channels. Such systems include, for example, paging communication systems, system broadcast messages or information and system positioning or location in which the information is transmitted to different target recipients. In some systems MPCR, for example, in communication systems, spread spectrum multiple access code division (mdcr), code channels formed by allocating orthogonal codes, for example, Walsh codes, or codes advanced multiple access technologies have been developed for transmitting information among a large number of users of the system. However, the technology of the modulation signals with the expansion of the range used in systems mdcr, provides significant advantages compared with other modulation schemes, especially when there is a need to provide communication services to a large number of users of the communication system. Such technology is described in U.S. patent 4901307 dated February 13, 1990 on "communications System spread spectrum multiple access using satellite or terrestrial repeaters", and in application for U.S. patent 08/368570 "Method and apparatus for using full spectrum transmitted power in communication systems spread spectrum tracking phase, time and energy of a signal of each user. Both these documents are assigned to the assignees of the present invention and attached to it by reference.

In these patents describes the communication systems, multiple access, in which each of many mainly mobile or remote system user uses at least one transmitter for communication with other system users or users of other communication systems connected to this system, such as the public switched telephone network Abbasova station.

The base station overlapping cells, and the satellites have a service area on the Earth's surface. In such a system, the increase in throughput can be achieved by dividing into sectors or split overlapping geographical areas. Cells can be divided into sectors by the use of directional antennas at the base stations. Similarly, the reception area, which is served by satellites, may be geographically separated through the use of focused beams. This can be used a special satellite antenna system forming such rays. This technology division served regions on the sector serves to separate access to subscribers by applying the relative orientation of the antennas or multiplexing with spatial separation of access. In addition, by providing the necessary communication bandwidth to each of these separate areas or sectors or beams can be assigned to channels mdcr due to seal split by frequency. In satellite systems, each channel mdcr called "Cablecom", as such channels may be more than one beam.

In standard systems in connection with the extension of the I modulation or spread spectrum user of the information signal within a predetermined band of the spectrum of this signal to perform modulation with carry on carrier for forming an output signal, transmitted over the communication channel. This method PSH-spread spectrum signal, is well known in communications technology, allows you to receive the transmitted signal with a bandwidth greater than the normal signal data. In base stations or communication lines "gateway-the end user", PN-code spread spectrum or binary sequences are used to distinguish between signals transmitted by different base stations, signals in different beams, and also distinguish between signals caused by multipath propagation. Such a code sequence is usually shared among all communication signals within a particular cell or sbloca.

In the standard system, spread spectrum communications mode mdcr codes are used to distinguish the various users within the cell or to recognize the signals of users are transmitted in the satellite subduce in a straight line (i.e., from the base station or the gateway to the user transceiver). This means that each user transceiver has its own orthogonally channel allocated to it in a straight line through the use of unique ortogonales code code for direct communication line is in the order of 64 elementary parcels for land systems and 128 elementary parcels for satellite systems.

Mainly satellite system mdcr produce a breakdown of your system resources to multiple gateways. The simplest distribution scheme is based on the sharing of resources across all channels mdcr or sublocal. The system allocates soluci separate satellites separate gateways for specified time intervals. However, if you have much more gateways than available sbloca, the distribution mdcr channels becomes potentially ineffective in the use of system resources. In such situations it is preferable to use separate sbloca between the gateways. This leads to an increase in the resolution of system resources available for allocation.

Therefore, if a large number of gateways is desired to separate one mdcr-channel or sublots between the gateways as a shared system resource. However, as is well known, the separation mdcr or MPCR channel between multiple transmitters leads to the creation of mutual interference between the transmitted signals at the receivers. Professionals working in the field of technology coding and communication, it is clear that this is true for both terrestrial (e.g., cellular) communication systems, often using basic communication.

Thus, there is a need for a method for allowing multiple transmitters (e.g., gateways, base stations) to share the same channel NCR without any mutual interference.

This invention relates to a system and method to allow multiple transmitters to share the same MPCR or mdcr channel through the use of orthogonal signals. Applicants are based on the fact that unlike traditional approaches, many transmitters subscribers can share the same MPCR channel through the use of orthogonal signals, when in accordance with this invention, certain aspects of the operation of the transmitter is limited. In addition, in accordance with traditional approaches, there is no possibility and phase control carrier signals from multiple transmitters for alignment shifts the phases of signals received by one or each of multiple mobile sinks. Applicants found that when using a methodology appropriate to the invention, certain operating parameters of the transmitted signal, type the relative phase of the carrier should not UPRAVLENIE functional characteristics of a transmitter in accordance with this invention, becomes practically possible to share MPCR-channel multiple transmitters.

In accordance with the preferred embodiment, presented in the invention, each transmitter shares the same mdcr channel by allocating him a part from a predefined set of Walsh codes, which can be used for the formation of channels of information signals of the user. All transmitters that share the resource system, broaden the spectrum user signals in the channels by using the same pseudotumor (PN) code expanding the range and offset. Transmitters can share the same frequency band (MPCR or mdcr-channel) without creating interference with the following limits for transmitters: each transmitter uses the same PN-code spread spectrum or two quadrature PN-code sequence and timing offset; timing offset pre-adjusted to provide temporary equalization in the receiver; frequency signals are pre-adjusted to provide frequency equalization in the receiver; and no one orthogonal channel code not destinations is sushestvennee of the present invention is the provision of a plurality of transmitters of opportunity to share the same mdcr channel without mutual interference.

This invention also allows multiple transmitters to share the same MPCR channel without mutual interference.

The advantage of this invention is to increase the signal-to-noise ratio for certain signals and communication systems.

Another advantage of this invention is the improved ability to track time and phase characteristics of the signals.

Another advantage of this invention is the improved ability to track the frequency of the signal.

And finally, another advantage of this invention is the improved ability to capture signal when it is detected.

Another objective of this invention is to allow the use of multiple pilot signals for tracking frequency. Since each transmitter, share mdcr channel, in accordance with this invention, provided the pilot signal, the set of pilot signals become available in the receiver for use in monitoring frequency. One of the advantages of using multiple pilot signals to determine the frequency lies in the fact that this provides faster signal capture on h low signal-to-noise ratio. In addition, the advantage of this method is the possibility of improving the quality of demodulation in the channel with strong fading; when the level of one pilot signal is decreased, its capacity can be expanded to include pilot signals from other transmitters, and still capture the carrier frequency. Another advantage of this method is the possibility to use the pilot signal with less power.

Further characteristics and advantages of the present invention, as well as the construction and principles of operation of various embodiments of the present invention will become more apparent from the detailed description given hereinafter with reference to the drawings.

This invention is illustrated below with reference to the drawings in which the same reference position indicate identical or functionally similar elements. While the first digit of the reference position indicates the drawing in which this reference position is found for the first time.

Fig.1 - typical communication system with multiple access; Fig.2A is a block diagram of the modulator signal in the traditional version; Fig. 2b is a block diagram of an alternative modulator signal in the traditional version; fidicina performance; Fig. 4 is a block diagram of the preferred alternative implementation of the present invention; Fig. 5 is a block diagram of a sequence of operations corresponding to a preferred variant implementation of the present invention; Fig. 6 is a block diagram of a circuit-locked loop using multiple pilot signals to estimate the carrier frequency of the received signal with Cfmn; Fig. 7 is a block diagram of a sequence of operations illustrating the operation of the circuit-locked loop according to Fig.6.

1. Introduction the Present invention is a system and method for providing multiple access through the sharing of the same MPCR-channel or single shared broadband signal resource. Discussed preferred embodiment of the invention. First, however, discusses a number of aspects of the invention, necessary for its understanding.

Although the description of the concrete steps, configurations and devices, it is clear that this is done solely for illustrative purposes. It is clear that other steps, configurations and devices can be used without changing the nature and scope of this invention.

As noted earlier, Alov, using the mode mdcr with the extension of the spectrum; each band is called in this case mdcr channel. Various mdcr-channels are used for transmission of communication signals to various receivers end users. Mdcr-channels can also be remapped to other systems for reuse in accordance with the various provisions of the Federal communications Commission or be separated by an intermediate frequency bands used by other communication services. Geographical areas served by different mdcr-channels may overlap partially or completely, depending on the version of the communication system. Users can switch from one mdcr channel to another depending on the quality of the received signal, the zone of visibility of the satellite repeater or its location, signal strength, interference, etc.,

In data transmission systems with mdcr many users, passing information from single locations can share the same frequency band (mdcr-channel) through the appropriate assigning each of them an orthogonal code channels, such as Walsh codes. In the standard system with mdcr available spectrum is divided into Ney on several code channels by using these codes to the signal, want to send. Each code channel is a separate data channel, capable of ensuring the transmission of voice, data, etc., In the preferred embodiment of the invention, each code channel, acting as part mdcr channel, is generated by modulation of the information signal, one of the Walsh codes selected from a set of Walsh codes. A typical set of known codes are published in the system specification IS-95 Standard compatibility mobile stations for cellular systems with wideband spread spectrum operating in full-duplex mode. The received communication signals are mutually orthogonal.

2. The formation of Walsh codes One type of orthogonal code channels is a Walsh code, which is used in the preferred embodiment of the invention. The formation of the Walsh codes and the peculiarities of their use are considered in U.S. patent 5103459 "System and method for generating signals in a cellular telephone system with mdcr". U.S. patent 5103459 ceded to the assignee of the present invention. Hereinafter, for convenience, a brief description of this invention.

It is well known that can be formed of sets of sets of orthogonal binary sequences for most lengths, ranging from four and up to two hundred. One of the classes of orthogonal binary sequences that can be used as orthogonal analiziruemykh codes and which can relatively easily be formed, called Walsh functions. The Walsh functions can be obtained from the matrices of the Walsh function, also known as the Hadamard matrices. The Hadamard matrix of order n can be recursively defined as:

wheremeans the additive inverse of N and for real field H1=1 (i.e.,=-1).

Accordingly, the first two matrices Hadamard 2 and 4-th order can be represented as:


Then the Walsh code is just one of the rows of the matrix functions Walsh (Hadamard matrix) and the matrix of Walsh functions of order n is a square matrix containing n functions or sequences, each of which has a length equal to n elements (bits).

The Walsh code Wnof order n (as well as all other orthogonal functions) has the property that the interval of code symbols, the larger n, the mutual correlation between all razovanie time with each other. Note that each sequence is different from every other sequence exactly half the bits. It should also be noted that only one sequence contains all units of (valid) and that all other sequences contain half of the units and half units minus.

The above properties of Walsh codes make them very useful when used in communication systems with mdcr. As will be described below, when two signals of the user respectively modulated using two different Walsh sequences from some set, then the two resulting signal does not create between themselves mutual interference.

3. Wireless information system
As noted above, this invention can be used in various wireless information systems and communication systems. Such systems include information broadcast system, usually used for paging or location. Other systems include wireless communication systems, such as satellite and terrestrial cellular telephone systems. Preferably the invention can be used in communication systems with mdcr with reservedno communication system, which can be used in this invention, is shown in Fig.1. In the fragment of the communication system 110 shown in Fig.1, uses two base stations 112 and 114, one satellite repeater 116, as well as two associated gateway or hub 120 and 122. These elements of the communication system shown as establishes a connection with two subscriber devices 124 and 126. In a typical case, the base station and the relay satellites/gateways are components of various communication systems, terrestrial and satellite, but this condition is not necessary.

Each of the subscriber devices 124 and 126 is composed of the wireless device, although not limited to them, and this device can be a cellular telephone, a data transceiver, or a paging receiver or data receiver for positioning; in addition, this device can be portable or if necessary, can be installed on any vehicle. In this case, the subscriber device depicted as mobile phones. However, it is clear that the principles of the present invention are also applicable to stationary installations where the provision of services to remote wireless keyboard is the case for the maintenance of a certain area of the satellite repeater 116 may be formed from multiple beams at different frequencies, also defined as mdcr-channels or subduce. It is clear that the service area of the beam or multiple satellites, repeaters and directional antennas of different base stations may overlap completely or partially the service area based on the destination of the communication system and the type of telecommunication services provided and depending on whether you want to provide spatial diversity.

Currently there is a large variety of communication systems based on several satellites, functioning, for example, in low-earth orbits to serve a large number of subscriber devices. It is clear that the principles of the present invention is also applicable to other configurations of satellite systems and gateways, using orbits of different height and other constellations. At the same time, the invention is equally applicable to terrestrial systems with different configurations of base stations.

In Fig. 1 shows a possible path signals for communication between subscriber devices 124 and 126 and the base stations 112 and 114 or via satellite 116 with gateways 120 and 122. Line the base station is a subscriber device" shown by lines 130, 132, 134 and 136. Line SW 142, respectively. Lines of communication satellite-relay-subscriber device between the satellite repeater 116 and subscriber devices 124 and 126 are shown with lines 144 and 146, respectively.

As noted above, the gateways 120 and 122 and the base station 112 and 114 can be used as part of a one - or two-way communication systems, or simply to send a message or data to user devices 124 and 126. In another case, the gateways 120 and 122 or base stations 112 and 114 may be required to share the same MPCR or mdcr channels. This is of particular importance when the base station 112 and 114 are located close to each other, or when the gateways 120 and 122 currently have an unequal number of allocation requests, or there are messages for the General user groups.

4. Expansion of the spectrum of the signal and the overlay code sequence
Before information signals will be transmitted to the subscribers of the system, they in the first place, if necessary, converted into digital form and encoded, and, if necessary, are interspersed to create a basic digital communication signal. These operations are well known in practice methods. The signals addressed to oprelostam, widening the spectrum of the signal allocated to a straight line that user. Thus, a unique orthogonal code for applying the information signal, it usually Walsh code is used to differentiate between users or subscribers within the cell or beam. As a result of such encoding in a straight line at the carrier frequency generated subscriber signals, also referred to as channels. Such orthogonal functions are sometimes called codes of channels.

A block diagram of a typical transmission schemes for expanding the range and overlay code sequence on the information signals shown in Fig.2A and 2b. Modulator 200 of the transmitted signal in Fig.2A uses the first multiplier 202, the second multiplier 204, the generator orthogonal code or function 206 and PN generator 208. In another embodiment, illustrated below, the modulator 200 can be used multiplier 210. Modulator 200 of the transmitted signal receives data or a pre-encoded information symbols and orthogonal codes or produces superimposed on the signal of a specific orthogonal code sequence, a Walsh code, and then expands the spectrum of the signal with the superimposed sequence before peredacha Walsh W(t). Generator orthogonal functions or Walsh code 206 generates an orthogonal code overlay required for the canalisation of the information signal, using technical means, well known in practice. Code Wi(t) from the generator 206 is multiplied by or merged with character data in the logical element 202, which is typically a multiplier. In an exemplary embodiment of the invention the orthogonal function is typically synchronized with a clock frequency of 1,2288 MHz, although you may be used and other known clock frequency.

An information signal with orthogonal superposition S(t)W(t) from the output of the multiplier 202 is fed to the input of logic element or multiplier 204, which multiplies the signal by extending PN-code. The resulting output signal, extended spectrum pseudotumour code and orthogonal coded next in a typical case, is subjected to bandpass filtering and transmitted to the appropriate circuit for further amplifying and adjusting the power level, and then used to modulate keywords. carrier. In another embodiment, a PN-code spread spectrum and orthogonal analiziruyuschei code can be multiplied together or volume at which the modulator of the transmitted signal 201 signals from the generator orthogonal code 206, and the generator PN-code 208 transferred to the multiplier 210. The multiplier 210 generates the combined code, which is then combined with the information signal S(t)W(t) in the multiplier 204.

The resulting signals may then be amplified and filtered before combining with other signals transmitted in a straight line. The operation of filtering, amplification and modulation are well known in practice. It is known that in alternative implementations may change the order of some of these operations for forming the transmitted signal. Further details on the operation of the transmitting system of this type is disclosed in the above U.S. patent N5103459.

PN generator generates one or more different PSH extends codes for use in this process. This generator may in time be divided among several transmitters using the corresponding interface elements. An example of an electronic circuit of the generator of these sequences disclosed in U.S. patent 5228054 "Generator psevdochumoy sequence length determined by the degree 2, with a quick shift" from July 13, 1993, assigned to the assignee of this invention.

In another embodiment, PSH-codes may be within the device with random access (SUPD). PN generator 208 may optionally generate at its output sequence with either the actual values or complex values. In some applications, these PN-code spread spectrum can also be a code shifted in phase by 90o.

Each PN sequence contains a sequence of elementary parcels, repeated at pre-selected period of the PN code with a frequency higher than the basic frequency band signal whose spectrum extends. Typical value of this frequency is a frequency at 1,2288 MHz PN code sequence length or period of 1024 elementary parcels. However, it is clear that the length of such a code may be selected to increase code division or reduce search time. Every implementation of the system determines the distribution PSH extends codes in the communication system according to factors known in the prior art.

To ensure data synchronization uses the well-known clock source frequency and time shifts or offsets are usually made by one or more control processors to synchronize these operations.

5. The expansion unit specticals known device for spread spectrum signals with quadrature phase shift keying (Kfmn). From the above it is clear how the present invention can be used by other schema extension signal. The block diagram of the device spread spectrum signal with Cfmn shown in Fig.3. The device 300 spread spectrum signal with Cfmn includes first and second common-mode multiplier products 302 and 304, the first and second quadrature multiplier products 306 and 308, two filters 310 and 312 and a summation element or adder 314. Two PN generator 316 and 318 are used to build the in-phase and quadrature extending PN codesIand PNQ, respectively, which are the same as PN generator 208, described above.

In Fig.3 shows an information signal S(t), which analiziruetsya by multiplication with a Walsh code W(t) and is converted thereby into channeled information signal S(t)W(t). Channeled information signal S(t)W(t) is fed to one input of each multiplier 302 and 306. In the General case, the same data are fed to the input of both multiplier products, and then combined with an individual code or modulate these individual code. The multiplier 302 multiplies the input signal S(t)W(t) in-phase PN code PNIcoming from the PN generator 216. The resulting signal then filtry, limiting the bandwidth of the transmitted signal. The filtered signal is then fed to multiplier 304, where it is multiplied by the phase with the carrier signal cos(wt). Similarly, the multiplier 306 multiplies the input signal S(t)W(t) and quadrature PN code PNQcoming from the PN generator 218. The resulting signal is then filtered by filter 312, and is supplied to the multiplier 308, where it is multiplied by the quadrature carrier signal sin(wt). Clear that can be used and also other signals as carrier signals. The resulting in-phase and quadrature components are then added together by the adder 314 to receive the signal from Kfmn spread spectrum M(t), which can be further amplified and filtered before combining with other ready signals a straight line, then the combined signal is radiated by the antenna.

6. The implementation of the present invention
Previously it was thought that many transmitters cannot share the same MPCR channel by combining the use of multiple orthogonal analiziruemykh codes. Further it has been shown that the joint use of the channels of the carrier phase of the transmitted signals must be exp is esta transmitters, geographically distributed in space, is difficult to implement, and it is believed that technically make an adjustment on interest bearing frequencies impossible. As shown below, the applicants rely on the fact that in contrast to traditional approaches, many transmitters can share a single MPCR channel using orthogonal analiziruya codes, even if the phases of the carrying respective transmitters are not aligned at the receiving end. Under certain circumstances, the transmitted signals remain mutually orthogonal, regardless of the phase of the carrier.

Proof that the carrier phase is not significant, it is better to lead by example. Consider two of the transmitter, the transmitter's and the transmitter Y, located at the base stations 122 and 114, or on the gateways 120 and 122. Each of them forms the main load-carrying signals having a phase "x" and "y" respectively. Transmitter X it channels information signal Sxusing the Walsh code Wx(i), and after the modulation of the carrier signal frequency is obtained transmitted signal Tx(t), where i corresponds to the number of elementary parcels sequence of Walsh. In this example, i find the Yu Walsh Wy(i), and after the modulation of the carrier signal frequency is obtained transmitted signal Ty(t). Then the transmitted signal can be represented as:


Both transmitted signals are accepted by the receiver X (124, 126), which is the removal of the overlay or the allocation of a channel using Walsh functions Wx(i). It is believed that during the preliminary correction of the frequency of any relative phase difference of the received signals is basically constant. Thus, although the phase may vary, they nevertheless remain relatively constant for the period of the Walsh functions used in this example. Since the product of a sequence of Walsh on the same Walsh sequence represents a single sequence for a signal Txthe relation is valid:

which describes the desired information signal. Since the product of the Walsh sequence to another sequence of Walsh from the same set is a zero, the signal Tydescribed by the ratio;

which shows that the curves above conditions and frequency alignment is not changed for a short period of the Walsh function.

In accordance with a preferred embodiment of the present invention, each transmitter uses the same pair of quadrature PN-codes or sequences and offsets. (The offset of the PN code is a predetermined delay between the reference time and the start time of the PN code sequence). In addition, none of orthogonal analiziruyuschei code is not used in more than one transmitter during the time period sharing mdcr channel. Offset pre-adjusted time to provide temporary equalization in the receiver. Frequency signals are also pre-adjusted to provide frequency equalization in the receiver.

A block diagram illustrating the preferred embodiment of the invention shown in Fig. 4. In Fig.4 shows a simple application of the invention, which uses only two of the transmitter, the transmitter 400 and the transmitter 400 share the same mdcr channel. In accordance with the preferred embodiment previously a certain set of Walsh codes is determined among transmitters that share these codes. It's about the 1(t)-Ww(t) allocated to the transmitter 400V, where "w" is the total number of Walsh codes in the set.

It is clear that the functions of the Walsh should not stand out or be grouped in a strictly sequential order numbers, and, if necessary, can be distributed in accordance with other distribution circuits. Thus, the present invention is not necessary to the function of the Walsh 1-16 allocated to the first transmitter, and the functions of the Walsh 17-32 allocated to the second transmitter in the form of a continuous "blocks" or sequence from 1 to n and from n+1 to w). For example, the Walsh function 1, 3, 5,..., 31 may be fastened to one transmitter at a time, as other uses Walsh functions with numbers 2, 4, 6, ..., 32. Functions can be distributed in small groups, alternating sequences or other known schemes. For the respective transmitters can be used any number of factions, combinations or orders of selection of the Walsh function, unless there is a situation in which the respective transmitters use the same Walsh code at the same time on the same shared MPCR channel.

An example of how these allocations are for the preferred option implementation izobreteniya (W), share a common beam and the frequency in the communication system with mdcr and spread spectrum. Assignable functions for a subset of the nine channels are listed with their corresponding functions Walsh.

In this description, the preferred implementation option presents the work of two transmitters and one receiver. It is clear that the principle of this invention can be extended to the case where a large number of transmitters and receivers share the same mdcr channel. In addition, it will be shown that the receivers can be replaced by relays (for example, satellite transceivers, terrestrial repeaters and so on), and that the pre-correction time and frequency in this invention can be performed by either the transmitter or repeater. For example, the pre-correction time and frequency can be made for a group of users by sharing the same transponder on the satellite or repeater and the provisional correction signal prior to its transmission by the transceiver.

In this description of the present invention are disclosed issues related to signal transmission. It is clear that this invention can be used greater of the signals in a cellular telephone system with mdcr", assigned to the assignee of the present invention.

Further, in accordance with the preferred implementation, the same PN polynomial and the offset is allocated to each transmitter to the shared communication resource. In Fig.4 shows how one quadrature pair of PN sequences PNQand PNIstand out both transmitters 400 A and 400.

In Fig.4 transmitters include a multiplier products A, B, device 300 spread spectrum signals with Cfmn, adders A, V, pre-correctors time 406A, B, pre-correctors frequency A, B and antenna A, M.

Chart of Fig.5 illustrates the preferred alternative implementation of the present invention. Here the preferred implementation of the present invention is described in detail with reference to Fig.4 and 5.

In Fig. 5 at step 502 multiple user signals have multiple transmitters, which must share the same mdcr channel. The signals of the users may be voice data, information data, etc., These signals are represented in Fig.4, as SA1-SAXfor transmitter A and SB1-SIfor the transmitter 400. At step 504, each polzovateley two user signals SA1-SAXand SB1-SBX, peremezhaemyh with the same code sequence of Walsh. Walsh codes shown in Fig.4 as W1(t)-Wn(t), is allocated to the transmitter 400A, a Wn+1(t)-Ww(t) allocated to the transmitter 400.

Next, at step 506, the output signals from each of the multiplier A, B represent signals with Cfmn with range, advanced one or more devices 300 spread spectrum signal with Cfmn, using the same pair of quadrature PN of polynomials and offsets. The operation of the device 300 of the spread spectrum signal with Cfmn described above in section 3. Next, at step 508 the resulting encoded by the Walsh code signals with Cfmn spread spectrum are summarized in each transmitter in the adders A and B, respectively. At step 510 the combined signals are pre-adjusted time in pre-correctors 406A, B, respectively, to ensure that the PN offset of the combined signals received from the outputs of the transmitters are aligned in time at the receiver or receivers, for which these signals are intended. As described above, the transmitter 400A, 400V in General placed at the base stations or gateways, and well-known CA is sustained fashion, the correction time can be easily determined.

At step 512 the combined signal pre-equalized by time, pre-adjusted frequency in the preliminary frequency offsets A, B to ensure that the combined signals received at the transmitter outputs will be aligned to the frequency in the receiver or receivers. At step 514 the combined signal is ready for transmission through antenna A, M.

From the above explanation it is clear how to improve the invention using other alternative embodiments.

7. Frequency estimation using multiple pilot signals
In mdcr-receiver carrier frequency of the signal transmitted by the transmitter, is usually estimated using the pilot signal from a single transmitter operating in the band this mdcr channel. Usually you want to minimize the power of the transmitted signal. However, the difficulties of tracking frequencies in systems with mdcr may be aggravated by the use of pilot signals of low power. A feature of this invention is that it allows the use of multiple pilot signals from a large number of transmitters that share mdcr channel for estimation of the carrier frequency transmitters. (K, the AK as the phases of the carrying transmitters that share the channels need not be in alignment, each transmitter transmits a separate pilot signal to enable subsequent coherent demodulation).

The block diagram schematic locked loop 600 running multiple pilot signals to estimate the carrier frequency of the received signal with Cfmn shown in Fig.6. The diagram in Fig.6 includes an antenna 602, the rotator 604, a transfer device PSH extension 606, the demodulator Walsh code 608, coherent filters the pilot signals 610 (610A-610N), the signal shaping circuit of the error in frequency 612 (612-612N), the adder 614, the filter ring locked loop 616 and a voltage controlled oscillator (VCO) 618.

Chart of Fig.7 shows the operation of the circuit-locked loop 600. Next, the operation of the circuit-locked loop 600 will be described in detail with reference to Fig.6 and 7.

In Fig. 7 at step 702 a combined signal comprising signals transmitted from multiple transmitters sharing mdcr channel, is received at the antenna 602. At step 704 the rotator 604 converts the received combined signal with decreasing frequency in the frequency band of the main signal. At step 706, the signal in the frequency band basis is authorized by the displacement of the transfer device PSH extension 606. At step 708, the signal in the frequency band of the main signal and captured PSH extension demultiplexers on separate channels Walsh from a to N via demultiplexer Walsh code 608. Among the thus obtained channel Walsh is one channel with the pilot signal for each transmitter, share mdcr signal. At step 710, each pilot channel is filtered into a coherent filters the pilot signal 610 A-N, which can perform the functions of accumulation and reset.

At step 712, each schema generation error signal 612A-N calculates a value proportional to the error frequency for each pilot signal. In the example implementation of the preferred embodiment, the error signal frequency is calculated by the product of vectors representing the current reference pilot signal and the previous reference pilot signal for the in-phase I and quadrature Q channel. For the current reference pilot signal Ik, Qkand the previous reference pilot signal Ik-1, Qk-1the resulting frequency error is defined as Ik-1Qk-Qk-1Ik. The error signal may be positive or negative; if the error signal is zero, it means no frequency error.

e 614. At step 716 the combined error signal is filtered by the filter 616. At step 718 the filtered error signal is converted into an estimate of the phase with the VCO 618. At step 720, the evaluation phase is used in the rotator 604 to control the phase of the received combined signal.

8. Conclusion
Although we have described above, various implementations of the presented invention, it is clear that they were proposed to illustrate solutions to problems for example only but not for limitation. Thus, the scope of the present invention is not limited to any of the above described variants of implementation, and is determined in accordance with the claims and its equivalent.


Claims

1. A way to provide opportunities for the sharing of multiple transmitters to the same channel multiplex transmission code division (MPCR) in the communication system MPCR, and each transmitter has a variety of communication channels for transmission of multiple data signals, comprising the steps of assigning a predetermined set of orthogonal code channels multiple transmitters predefined way and each PE is orthogonal code channels to create a set of information signals of the channels, spread spectrum multiple information signals of the channels using at least one pseudotumor (PN) code to obtain a variety of information signals with spread spectrum, the summation of multiple information signals with spread spectrum before transmission to the formation of the composite signal and the correction frequency composite signal prior to transmission so that the composite signal has been adjusted in frequency when the reception.

2. The method according to p. 1, characterized in that the said codes of the channels are Walsh functions.

3. The method according to p. 2, characterized in that any one of the Walsh functions simultaneously appoint more than one transmitter.

4. The method according to p. 3, characterized in that one PN-code spread spectrum assign multiple transmitters.

5. The method according to p. 4, characterized in that the composite signal from each transmitter pre-adjust the time before the transfer so mentioned PSH-codes composite signals are aligned in time at the reception.

6. The method according to p. 1, characterized in that the communication system MPCR includes a wireless communication system, multiple access, code-Razdelnaya, and the aforementioned step of forming the channel includes forming a channel for each of the user signals using one of the mentioned orthogonal code channels to create a channel user signal.

7. The method according to p. 1, characterized in that it further includes the steps of receiving at least two user signals that share the same channel, in the form of a composite signal, compressing the received signals in accordance with at least one predefined PN-code spread spectrum, demuxing composite signals in many individual information signals in accordance with pre-selected orthogonal code channels, coherent filtering each of the at least two pilot signals corresponding to the individual information signals, signal errors for each of the filtered pilot signal and summing the resulting signals of the error.

8. The method according to p. 7, characterized in that it further includes the steps of conversion with decreasing frequency of the received signals are spread spectrum in the baseband frequency signal before demultiplexing, filtrem frequency signals in accordance with the filtered summed signals of the error.

9. The method according to p. 8, characterized in that the said step of generating the error signal includes forming the cross-product of the current samples of each of the pilot signals and the previous samples.

10. Communication system MPCR with multiple transmitters, each of which transmits at least one information signal, together using the same MPCR channel, in which each of the transmitters includes at least one channel signal processing for transmission of an information signal, a multiplier for combining each of the information signal with a different orthogonal code channel, the adder, connected to the TV signal processing, for summing the signals generated by the signal processing before transmission of each transmitter, the pre-time correction, coupled to the adder, for pre-correction signal generated by the adder, so that PN codes transmitted signals from multiple transmitters are aligned with the reception time, and the pre-equalization, coupled with pre-time correction for pre-correction signal generated by the block prejudicial, are aligned with the reception on time and frequency.

11. The system under item 10, characterized in that the said orthogonal codes of the channels are Walsh functions.

12. System on p. 11, characterized in that none of the Walsh code at the same time is not assigned to more than one transmitter.

13. The system under item 12, characterized in that each of the channels of the signal processing device spread spectrum, coupled with the multiplier, spread spectrum signal generated by the multiplier, using at least one PN-code spread spectrum.

14. System on p. 13, characterized in that one PN-code spread spectrum is assigned to multiple transmitters.

15. System on p. 13, characterized in that the device spread spectrum is performed in a device of the spread spectrum signal with a quadrature phase shift keying (Cfmn), and mentioned at least one PN-code consists of a pair of quadrature PN-code spread spectrum.

16. The system under item 10, characterized in that the communication system MPCR includes wireless system mdcr spread spectrum, each of the information signals is a custom signal, and the aforementioned at least Tinel Association provides each user signal with a different orthogonal code channel.

17. Communication system MPCR with multiple transmitters, each of which conveys a lot of information signals, together using one MPCR channel where each transmitter includes means for assigning a set of orthogonal code channels multiple transmitters predefined way, the means for forming a channel for each of these sets of information signals using one of the orthogonal codes of the channels to form multiple information signals of the channel, means for expanding the range mentioned multiple signal channels using at least one PN-code spread spectrum for multiple signals with spread spectrum, means for summing the set of signals with spread spectrum before transmitting them to obtain a composite signal, and means for pre-equalization of the composite signal prior to transmission so that the composite signal has been adjusted in frequency when the reception.

18. The system under item 17, wherein the orthogonal codes of the channels are Walsh functions.

19. The system under item 18, characterized in that none of the Walsh code at the same time not naznachen oznachaet multiple transmitters.

21. System on p. 20, characterized in that it further comprises means for pre-time correction of a composite signal of each transmitter before transmission so that the PN-codes composite signals are aligned in time at the reception.

22. The system under item 17, characterized in that the communication system is a communication system mdcr spread spectrum, and the information signals are user signals that share the same mdcr channel, and means forming channels includes means for forming a channel for each of the user signals using one of the orthogonal channel codes to create a custom channel signal.

23. The communication system under item 17, characterized in that it further comprises means for receiving at least two user signals that share the same channel, in the form of a composite signal, means for compressing the received signals in accordance with at least one predefined PN-code spread spectrum tool for demuxing composite signals in many individual information signals in accordance with prewar the least two pilot signals, relevant individual information signals, means for forming an error signal for each of the pilot signals and means for summing the output signals of the error.

24. Communication system by p. 23, characterized in that it further comprises means for converting the lower frequency of the received signals with spread spectrum in the baseband frequency signal before demultiplexing means for filtering the summed result of error signals, and means for regulating the means for converting, in accordance with the filtered summed signals of the error.

25. Communication system by p. 23, characterized in that the means of generating the error signal includes means for forming the cross-product of the current samples of each of the pilot signals and the previous samples.

26. The method of error detection frequency in the communication system MPCR with many transmitters that share the same MPCR channel, each transmitter transmits at least one signal in the channel formed using one of the multiple orthogonal codes, channels, expanded using PSH-to and the method includes the steps of receiving a composite signal, containing a number of individual signals, which are transmitted by at least one of the multiple transmitters, compression of the composite signal using the PN-code spread spectrum, demuxing the composite signal into a number of individual signals in accordance with a set of orthogonal code channels, coherent filtering each of at least two of the multiple individual signals, the signal errors for each of the filtered individual signals and summing the signals of the error.

27. The method according to p. 26, characterized in that it further includes the steps of conversion with decreasing frequency of the received composite signal in the primary frequency band signal before demultiplexing, filtering the summed signal errors and adjustments referred converted to a lower frequency signals in accordance with the filtered summed signals of the error.

28. A device for error detection frequency in the communication system MPCR with many transmitters that share the same MPCR channel, each transmitter transmits at least one signal in the channel formed using a single sustained fashion adjusted in frequency to align with the frequency at reception containing means for receiving a composite signal containing a number of individual signals, which are transmitted by at least one of the multiple transmitters, means for compressing the composite signal using the PN-code spread spectrum tool for demuxing composite signal into a number of individual signals in accordance with a set of orthogonal code channels, means for coherent filtering each of at least two of the multiple individual signals, means for forming an error signal for each of the filtered individual signals and means for summing the signals of the error.

29. The method according to p. 1, characterized in that it further comprises a pre-correction time mentioned composite signal of each transmitter before transmission so that the PN-codes composite signals are aligned at the reception on time.

30. The system under item 17, characterized in that it further comprises means for pre-time correction mentioned composite signal of each transmitter before transmission so that the PN-codes composite signals are aligned at the reception on time.

 

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