Method of transmitting and receiving data, system and receiver for its implementation

 

The invention relates to digital communication. The technical result is to increase the range of operation of the transmitter without increasing its size and cost. The inventive method and system data signals passed at an unknown frequency within a known frequency range. In the receiver frequency range is divided into multiple frequency bands, each of which has a width smaller than the error in the transmission frequency of the data signal. In at least one of the frequency bands detected the presence of a data signal, and the detected data signals demodulated. Thus, it can be used cheap transceiver, allowing two-way communication between the receiver and the transceiver. 8 C. and 42 C.p. f-crystals, 6 ill.

The present invention relates in General to a method of digital communication and digital communication.

Known to the applicant tracking system for vehicles, which is used in the UK, allows police to track and return stolen cars. In this known system, car hid a small transceiver unit. This unit is activated by the activation signal, to transmit signals when AB is by the receivers, which allows them to receive signals transmitted by transceiver unit in the stolen car. Thus, the police can track the vehicle to determine its location and to return the stolen vehicle.

The tracking system may include additional and more complex functions, if between the transceiver unit in each vehicle and a base station, usually the nearest base station, there is a two-way communication, and the base station could act as a receiver for receiving data transmitted in the signals from the transceiver unit. This double-sided or duplex communication is not possible with known systems because of the disproportionality of power from on-Board transceiver unit and power from the base station. In particular, base stations have transmitters with a power of 25 W and a distance of about 30 miles (about 50 km). Each side of transceiver block has a transmitter power of 1 watt and a maximum distance of 1.5 miles (2.5 km), which is often insufficient to establish communication with the base station. You cannot just increase the power transmitting side blocks, as this would increase their size and cost is, what you can reduce the bandwidth of the transmission. This would reduce the speed at which information is transmitted, but for many applications, for example, tracking system, this reduction in speed is acceptable. Commonly using the transmitting unit with the reduced width of the strip increases the cost of each transceiver block, since then, in the transmitting-receiving unit, you will need to use high precision components. This is because the error or the error of the carrier at the transmission frequency should normally be less than the bandwidth of the transmitted signal so that the receiver can determine the location of the data. However, because the market does not accept blocks that have a significantly higher cost, therefore, in such a transceiver may be used high-precision components.

The present invention is directed to increasing the range of operation of the transmitter without increasing its size or value. The present invention also aims to increase the transmission distance of the signals containing the data from the transmitter without increasing its size or value. The present invention has particular application in the tracking system is cheap transmitters.

In EP-A-0583522 disclosed remote system positioning. The spatial location of the many mobile transceivers can be defined as a base station that receives signals from the location from the mobile transceivers. Mobile transceivers use the mode of transmission with frequency hopping spread spectrum, each mobile transceiver has its own characteristic combination of frequency hopping, to the base station based on a specific combination of frequency hopping in the incoming signal was able to determine which the mobile transceiver is transmitting. Thus, if the transmission frequency used by each mobile transceiver is a critical parameter with regard to its correct identification of the base station, it is essential that the base station is transmitted to the mobile transceivers clock signals time binding, and mobile transmitters, respectively, must be relatively complex (and therefore expensive) due to the fact that they must contain storage devices and circuits, CTCI frequency. In addition, the signals transmitted by mobile transceivers, not modulated and, therefore, do not contain any data transmitted to the base station, since the only information used by the base station, is the fact that identified specific movable really transceiver transmits. Therefore, between the base station and mobile transceivers there is no two-way data exchange.

In EP-A-0550146 disclosed a digital processor for processing multiple analog signals received respectively from a variety of mobile transmitters.

According to the first aspect of the present invention, a method for transmitting and receiving data, and the method comprises the steps: transmitting a narrowband data signal at an unknown frequency within a known frequency range; receiving the signal data within a known range of frequencies; separation in the receiver frequency band into multiple frequency bands, each of which has a width smaller than the error in the transmission frequency of the data signal; detecting the presence of the data signal in at least one of the specified frequency bands and demodulating the detected signal is a narrowband filter at the frequency bands of the detected data signals.

The frequency of the or each notch filter phase demodulation is preferably determined during the discovery phase.

Time of data signals in a narrow frequency bands preferably determine the detection step and used in the demodulation step.

In the most preferred embodiment of the present invention the step of detecting the presence of data signals at least one of the frequency bands includes the step of detecting the presence of a data signal in multiple frequency bands, and the amplitude of the data signal in each band is compared with the normalized value for determining the quality assessment of the data signal in each band.

The transmitted data signal preferably includes a flag sequence and the calculation of the center of gravity is preferably performed according to the quality to get the center frequency, and Central time for each flag sequence, and the results of a calculation of the center of gravity is used during the demodulation of the data signal.

The frequency of the transmitted data signal can be variated between consecutive transmissions. This ensures the reception of the useful signal, even if the specific is unlikely to impact the same interference.

The data signal is preferably passed into two subchannels, and the stages of detection and demodulation performed on each subchannel, and the corresponding demodulated data signals are weighed and summed in accordance with the quality of the signals defined on the stages of detection.

The received signal may include multiple narrowband data signals, each of which occupies a separate portion of the channel, and the receiver accepts the narrowband data signals essentially in parallel. This allows the receiver to receive transmissions from multiple transceiver blocks essentially in parallel.

After each detection step can be performed in many stages of demodulation.

One variant of implementation of the present invention increases the effective range of the transmitter by providing essentially narrowband communication between the transmitter and receiver. This increases the range at the same power, but with some decrease in data transfer speed, which can be used as narrow-band communication is provided a method of signal processing in the receiver, there is no need to have more accurate and therefore more operette by using direct FMN (frequency shift keying) modulation.

The data signal preferably contains a data packet that follows the flag sequence of bits, and the detection step detects the existence of the flag sequence. In the present preferred embodiment, the data signals in a separate narrow frequency bands is compared with the desired flag signal at regular intervals. As a result of these comparisons get data about the exact timing, frequency and quality, which allows to optimize the detection step.

For reliable detection, it is preferable to perform the transmission of packet data between the start and tail flag sequences, and the detection step requires detection of the two flag sequences.

Preferably you want to confirm if the data packet was detected in both basic and tail flag sequence. This greatly reduces the likelihood of false detections. In addition, the flag sequence determine information about the frequency and timing for phase demodulation. The presence of flag sequence before and after each data packet allows the use of frequency and time binding with demo data separated from each flag sequences. Thus, if there are n data packets, the data signal will be n+1 flag sequences. Using phalangeal sequences as a means to detect the presence of data and provide information about the frequency and timing for resolution of the demodulation means that external synchronization between the sending unit and the receiver is not required.

In a preferred embodiment, the step of detecting the presence of data signals in a separate narrow frequency bands includes the step of detecting the presence of the flag sequence in the many narrow frequency bands, and the amplitude of the bits of the flag sequence in each band is compared with the normalized value to determine a quality assessment of discharges flag sequence in each band, while building the graph of the quality evaluation of frequency and time.

Pre-calculate the "center of gravity" according to the quality to get the center frequency, and Central time for each flag sequence, and the results of a calculation of the center of gravity is used for demodulation of the data signal.

According Eichen device is a radio transmitter to transmit narrowband data signal at an unknown frequency within a known frequency range and a receiver for receiving a data signal within a known frequency range, moreover, the receiver has means for dividing the frequency band into multiple frequency bands, each of which is less than the error in the transmission frequency of the data signal; means for detecting the presence of the data signal in at least one of the specified frequency bands, and means for demodulating the detected signal data.

According to a third aspect of the present invention, a method of receiving data transmitted in the form of a narrowband data signal with an unknown frequency within a known frequency range, and the method comprises the steps of receiving a data signal within a known range of frequencies; separation in the receiver frequency band into multiple frequency bands, each of which is less than the error in the transmission frequency of the data signal; detecting the presence of the data signal in at least one of the specified frequency bands and demodulating the detected signal data.

According to a fourth aspect of the present invention proposed a receiver for reception and demodulation of the data signal transmitted on an unknown frequency within a known frequency range, and the receiver includes means for dividing the frequency band into multiple frequency po specified data signal in at least one of the specified frequency bands, and means for demodulating the detected signal data.

In a preferred embodiment, the specified receiver includes an analog-to-digital Converter (ADC), and the sharing tool contains a fast Fourier transform (FFT).

In one embodiment, the demodulation means includes means filter set to pass only the Central frequency, defined by the specified locator.

Preferably the specified separation specified detection and specified to perform demodulation in digital form in the digital process signals.

Preferably, the receiver had a detection and demodulation to detect and demodulate data transmitted on two subchannels, and preferably, it further contains a tool addition for weighting and summing the respective demodulated data signals in accordance with signal quality determined at the steps of detection.

Providing a valid two-way communication between the base station (which may have a relatively high power and can be expensive) and many transceivers (which may have low power and can be cheap), the present invention significantly improves significantly, what about this transceiver can send a data signal to the base station to confirm that it is activated, thereby providing the base station with assurance that the activation signal received, and allowing the base station not to repeat the signal many times to ensure its adoption, as it has done in the past. The transceiver may be sent to the deactivation signal, which can also be confirmed by the transceiver, so that the base station can verify that the signal deactivation was adopted and thereby prevent the support of a false or erroneous activation. To the base station can also be sent to the data relating to the state of the transceiver (such as the state of the transceiver unit, the voltage of the battery and so on), resulting in a base station will be able to continuously monitor the status of the transceiver unit. From time to time, the base station may send a test signal to each transceiver unit to ensure that these blocks work correctly, when this transceiver blocks respectively capable to react to this; known from the prior art tracking system for vehicles as described above, there is, for p the technical maintenance and testing of each block by performing physical connections to this unit during each service.

The present invention is specifically applicable to the tracking system for cars. So, you may be prompted tracking system cars with the system or the receiver in accordance with any of the aspects described above. Also can be provided a method for transmitting and receiving data, and a method of receiving data described above, in the tracking system of the car.

Further disclosed as an example of a variant of implementation of the present invention with reference to the accompanying drawings, in which: Fig.1 - receiver communication system according to the invention; Fig.2 - the received signal converted to an intermediate frequency; Fig.3 - scheme of the discovery process in PDB (Professor of digital signals); Fig.4 is a diagram of the demodulation process in the PDB; Fig.5 signal data received by the receiver; Fig.6 - "the spot" detection and illustration of the calculation of the center of gravity.

Described herein receiver and communication system have General application. However, for clarity, these systems and methods are described specifically as applied to the tracking system for recovering stolen vehicles. However, it is obvious that the invention is not limited to specified tracking system. For example, the present invention can be applied is th telemetry from remote (e.g., not fed from the power supply) installations, such as water tanks; personal security alarms or detectors damages or protective relays from attack, for example, attempted rape, signaling for rescue in the mountains, etc.; security of buildings, low-power wireless alarm connection alarm building with state centralized system of control; remote control in the household, for example, to control the electrical devices; and a communication system not on the radio, where it is used, for example, transmission of signals through the network power supply.

The methods disclosed below, allow you to use essentially the well-known low-power transmitter or transceiver unit to provide two-way communication. In particular, in the above specific example, the methods disclosed below, allow the use of essentially known low power transceiver unit to provide two-way on-Board communication vehicle, but with increased range comparable to the range of the base station. Range transceiver is increased by reducing the width of the frequency band by afco on the same lane. Therefore, the only change that needs to be done in the transmitting unit, is to reduce the transmission rate, because the system will behave as if it were actually conducted narrowband transmission. As discussed below, the receiver accept the channel is divided into a number of narrow strips, each of which can be detected and demodulated information. The use of a narrow band of frequencies in the receiver has the advantage that it reduces the impact of noise as a white noise, by definition, has a uniform energy distribution across the strip width.

In a specific example, the power transmitted by the onboard transceiver unit 25 times less than the power of the base station. The receiver at the base station should provide gain to compensate, plus an extra boost to match the increased levels of noise and interference. In addition, the transmission can be noisy in other programs, for example, from other transmitting units located close to the base station.

In one embodiment, the on-Board transceiver block has a Central carrier frequency in the VHF (very high frequency) range with a channel width of 12.5 kHz and performs peut on a carrier signal by frequency-shift keying (FMN) with a deviation of2.5 kHz and a transmission rate 55.8 bits per second. FMN modulation with such a low data rate creates a range that has the appearance of two narrowband AM (amplitude modulation) spectra, separated by intervals of 5 kHz, and one lane of data is inverted relative to the other, because to a large extent can be considered that the transmitted data is transmitted either in the higher or in the lower band, created in the course of FMN. Higher bandwidth is defined to accommodate the inverted sequence.

Preferably, the Central frequency for transmission from the transceiver unit slightly varied ("trembling") on subsequent packets of the message so that if the message is too noisy interference in the transmission line at the same frequency of the transmitted data signal, it was possible with high probability to receive this message through the next transmitted data signal. In this regard, the range of center frequencies is limited to250 Hz.

In Fig.1 shows the architecture of one possible implementation of the receiver 1 to the base station. In the General case, the receiver 1 includes a section 2 analog receiver attached is a normal FM (frequency modulation) the discriminator, otherwise data may be lost, since the signal level of the data is usually much lower than the noise level.

Section 2 analog receiver includes a Converter 6 with decreasing frequency, which converts the carrier frequency of the received data signal in an intermediate frequency (if). The value of FC may be, for example, 14 or 15 kHz, which allows the use of well-known cheap stereo audio analog-to-digital Converter (ADC) 8, on which the data signal is supplied directly by the Converter 6 with decreasing frequency.

In Fig.2 shows the spectrum of the converted data signal, which is issued by the Converter 6 with decreasing frequency before it is converted into digital form by the ADC 8. As you can see, the converted data signal is the sub-channel on each side of the inverter, and the lower sub-channel has a center frequency f1 and the upper sub-channel has a center frequency fu, which are separated by 5 kHz. Each sub-channel or band has in this example, the variation of the frequency of 3.57 kHz.

The converted data signal is supplied from the inverter 6 to the left and right stereo inputs ADC 8, where they are converted into digital form with a sampling frequency of 57 kHz. As shown in Fig.1 or more yetabrubtly signal through the synchronous serial port 14. These left and right signals are summed in the PDB 10 and converted to a numeric floating-point format, as shown at position 101. This summation signal is used to suppress at least some part of the noise that is generated in the ADC 8. The resulting values recorded in memory for subsequent demodulation, as will be described in more detail below. PDB 10 can work with blocks of samples, recording, for example, in the memory of several blocks while other blocks are processed. This gives you the opportunity to receive transmissions from multiple on-Board transceivers and to act effectively at the same time using a single base station receiver.

Then the meaning of section 101 PDB 10 is mixed with two local digital generators 102, 103 so that the generated two sets of data at different frequencies. The following description refers to the steps of detection and, although it specifically describes the data set of the upper subchannel, it is obvious that the same operations are performed with the data set of the lower subchannel, preferably at the same time.

The sub-channel is subjected to filtration to skip only the desired podkinulo frequency and thinned out (i.e. reduce) with a factor of 8, as shown in the position in the buffer 105. The data in the buffer 105 arranged at a predetermined window of the form 106 so that applied to these data, fast Fourier transform (FFT) 107 implements an overlapping set of bandpass filters. Each of the thus created bandpass filter has a narrow band33 Hz, and bandpass filters overlap with division 14 Hz.

FFT is performed once with 256 raw samples from the ADC 8. Average 256 frequency output signals FFT 107 represent the sub-channel, each signal is separated 14 Hz in the corresponding element of separation in frequency. For each of the 256 output signals perform the test on the quality of compliance with previous values from the previous interrupt, as shown at position 108. The output signal from the FFT 107 for each frequency tested against a perfect representation of famous flag sequence; this flag sequence will be additionally described below with reference to Fig.5. The output signal test to determine where you can expect and where to expect a lack of energy. A positive result of the evaluation of the quality of compliance will be when it is assumed that the minimum energy in the sample, where videobrown signal and is called the disclosure "eye" ("eye opening").

When data present flag sequence, the disclosure of eyes appear in a few frequencies, because the bandwidth of the FFT filter is greater than the spacing of the output frequency. The opening of the eyes appears after several time intervals, because the data at this point four periodicreview. Typically, the detection flag sequence occurs three or four temporary positions. Additionally, qualitative detection flag sequence probably covers up to six items resolution frequency.

The presence of flag sequence will cause so peak or "spot" ("blob") in the space frequency/time, which is represented as an example in Fig.6. To measure the peak center use the algorithm 109 "center of gravity" with much greater accuracy in frequency than the frequency separation of the output signals of the FFT, and the character time to 1/32 bit. Also write down all the "mass" of the peak, to provide a qualitative measurement of the peak. This calculation increases the ability to distinguish between valid and spurious signals and increases the accuracy of frequency and time estimates for subsequent demodulation.

Then these measured parameters for use with obnarujennyi in the lower subchannel, combine with the peak top of the subchannel, if the times and frequency of detection are within predefined limits. However, although through the use of upper and lower subchannel noise, if possible, can be reduced, the process of demodulation does not require detection in both, top and bottom, the subchannels, but rather the detection of only one subchannel.

After completion of the discovery process PDB 10 has sufficient time to perform the process of numerical demodulation before should be performed following detection. These processes consistently perform demodulation. The demodulation process continues to 63 bits of data. Since the discovery procedure perform each 1/4 of the discharge, any one demodulation process will continue for 252 interrupt, thereby gradually restoring data.

Please refer to Fig. 4, where each process of demodulation is performed by the same raw data as the detection process described with reference to Fig.3. The demodulation process uses the total float values calculated when detected at step 101 in Fig.3; step specified by the position 201 in Fig. 4, is identical to the step indicated by position 101 of Fig.3. P is o that is only one category of data, and only 1 in 4 times performing this process.

In particular, the input set of samples are mixed accordingly, as shown at positions 202 and 203, so that the desired signal in the upper subchannel will be a DC signal and the desired signal in the lower subchannel will be a DC signal. This is achieved by the mixers 202, 203, the phase change which one sample is accurately calculated by the measured frequencies of the discovery process described above.

Since the desired signals are converted to DC signals, then through low-pass filters can pass each of the two data streams, and sampling rate can be significantly thinned or reduced, as shown at positions 204, 205. Can then be set at 1/32 the timing for discharge of each signal using the corresponding lines 206, 207 variable delay. The length of this delay line is determined in advance based on time binding, obtained from the detection process described above. Then the data feeds additionally subjected to low-pass filter and the sampling rate is reduced, as shown at positions 208, 209, so that the final spacecannon combined with appropriate weights, obtained from the detection process in accordance with the quality of the signal, as shown at positions 210 and 211, and then summed, as shown at position 212. Then decide, as shown at position 213, that is whether the resulting value is the digit "1" or the digit "0", and this is the test threshold, which is also derived from the discovery process.

The individual bits of the demodulation process is collected in full messages, which are then passed from PDB 10.

In Fig. 5 shows the structure of a simple message transmitted from the transmitting side block, here in the form of one data packet. As shown, each data signal 20 has a 4-bit sequence 22 points 0101, followed by an 8-bit flag sequence 24, followed by a 4-bit sequence 26 of zeros or blanks 0000. In this example, 8-bit flag sequence 24 is 10001101. In order to increase the efficiency in the detection process, the detection algorithm searches for the extended 10-bit sequence starting from the last unit sequence 22 points and ended the first zero of the zero sequence 26. Thus the detection algorithm searches 10-the sufficiency and zero sequence 22, 24, 26 should package 28 data from 63 bits of data, and then for a package of 28 data are respectively a sequence point, the flag sequence and zero sequence 22', 24' and 26'. The tail sequence is used to confirm the presence of 28 packet data, allowing thus to avoid false detections.

Transceiver on Board the vehicle in a single message can be sent multiple data packets. Each data packet is separated from the next and previous data packet of flag sequence and flag sequences are available at the beginning and at the end of the message so that each data packet can be correctly detected. Thus, if there are n data packets, then there are n+1 flag sequences.

In the above description made with reference to a specific frequency and the dimensions of the channels. However, it is obvious that they are given only as an example and, if necessary, can be used alternative values. In addition, it is obvious that the above described hardware and software implementation are only examples and that within the scope of the present invention can be made of modifications and changes.

2. The method according to p. 1, wherein the step of demodulating includes centering at least one of the detected frequency bands of the signal data that is executed by at least one narrow-band filter.

3. The method according to p. 2, characterized in that the frequency of each notch filter phase demodulation determine the detection step.

4. The method according to any of paragraphs.2 and 3, characterized in that the timing of data signals in a narrow frequency bands determined during the discovery phase and use phase demodulation.

5. The method according to any of paragraphs.1-4, characterized in that the step of detecting the presence of data signals includes detecting the presence of a data signal in multiple frequency bands, and the amplitude Sunnah in each band.

6. The method according to p. 5, wherein the estimated quality carry out the computation of the "center of gravity" to provide a Central frequency, and Central time for each flag sequence, the results of the calculation of the "center of gravity" is used in demodulation of the data signal.

7. The method according to any of paragraphs.1-6, characterized in that the data signal is formed by modulating the carrier by FMN (frequency shift keying).

8. The method according to any of paragraphs.1-7, characterized in that the frequency of the transmitted data signal change between successive transmissions.

9. The method according to any of paragraphs.1-8, characterized in that the data signal is passed through two subchannels, and the detection and demodulation performed on each subchannel, and the corresponding demodulated data signals are weighed and summed in accordance with the quality of the signals identified in the discovery phase.

10. The method according to any of paragraphs.1-9, characterized in that the received signal contains many narrow-band signals, each of which occupies a separate portion of the channel, and the receiver accepts the narrowband data signals essentially simultaneously.

11. The method according to any of paragraphs.1-10, what about any of paragraphs.1-11, wherein the data signal includes a data packet following the flag sequence of bits, and the detection step detects the existence of the flag sequence.

13. The method according to p. 12, characterized in that a separate narrow bandwidth compared with regular intervals with the desired flag signal.

14. The method according to any of paragraphs.12 and 13, characterized in that the packet data is passed between the initial and tail flag sequences, and the detection step performs the detection of the two flag sequences.

15. The method according to p. 14, characterized in that to check the availability of the data packet detect both primary and tail flag sequence.

16. The method according to any of paragraphs.12-15, characterized in that the data signal has many data packets are separated from one another flag sequences.

17. The method according to any of paragraphs.12-16, characterized in that the step of detecting the presence of data signals in a separate narrow frequency bands carry out detection flag sequence into multiple narrow frequency bands, and the amplitude of the bits of the flag sequence in each band is compared with inormirovanny the m building plot of quality assessments of frequency and time.

18. The method according to p. 17, characterized in that the computation of the "center of gravity" performed by quality assessments to ensure that the Central frequency, and Central time for each flag sequence, and the results of a calculation of the "center of gravity" is used in demodulation of the data signal.

19. Method of transmitting and receiving data, which transmit the data signal at a frequency within a known frequency band, taking the data signal within a known frequency range and demodulator detected signal data, wherein the data signal is a narrow-band data signal of unknown frequency and the frequency range of the receiver is divided into multiple frequency bands, the width of each of which is smaller than the error rate of the data signal, and detect the presence of the above-mentioned data signal in one of these frequency bands, and the detection of data signals in a narrow frequency bands includes the detection of the data signal in a narrow frequency bands, the amplitude of the data signal of each band is compared with the normalized value for determining the quality assessment of the data signal in each band.

20. Device for transmitting, receiving, and demonstate, a receiver for receiving a data signal within a known frequency band and means for demodulating the detected signal data, wherein the transmitter provides transmission of narrowband data signal at an unknown frequency, and the fact that the receiver has means for dividing the frequency band into multiple frequency bands, the width of each of which is smaller than the error rate of the data signal, and a means to detect the presence of a specified narrow-band data signal in at least one of the specified frequency bands.

21. The device according to p. 20, characterized in that the receiver includes an analog-to-digital Converter (ADC), and the sharing tool provides a fast Fourier transform (FFT).

22. Device according to any one of paragraphs.20 and 21, characterized in that the demodulation means includes a filter, ensuring the transmission of only the center frequency defined by the specified locator.

23. Device according to any one of paragraphs.20-22, characterized in that the said means of separation, detection and demodulation provided by the digital signal processor.

24. Device according to any one of paragraphs.20-23, wherein the receiver includes means for onlyhello includes a tool addition for weighting and summing the respective demodulated data signals in accordance with signal quality, specific detection.

25. Device according to any one of paragraphs.20 to 24, characterized in that the means for detecting the presence of a data signal in a narrow frequency bands includes means for comparing the amplitude of the signal in each band with a normalized value for determining the quality assessment of the data signal in each band.

26. Device for transmitting, receiving and demodulating transmissions containing a transmitter for transmitting a data signal at a frequency within a known frequency range, a receiver for receiving a data signal within a known frequency band and means for demodulating the detected signal data, wherein the transmitter provides transmission of narrowband data signal at an unknown frequency, and the fact that the receiver includes means for dividing the frequency band into multiple frequency bands, the width of each of which is less than the error of the transmission frequency narrowband data signal, and means for detecting the presence of the data signal in at least one of these frequency bands, and means to detect the presence of data signal includes means for comparing the amplitude of the data signal in each band with the normalized value Ataraxie device according to any of paragraphs.20-26.

28. Tracking device for car, which uses a method of transmitting and receiving data according to any of paragraphs.1-19.

29. The method of receiving data transmitted in the form of a data signal at a frequency that is within a known range of frequencies at which signal data within a known frequency range, and demodulator detected signal data, wherein the data signal is a narrow-band data signal of unknown frequency, and the fact that the receiver share a frequency band into multiple frequency bands, the width of each of which is smaller than the error rate of the data signal, and detect the presence of a specified signal data in at least one of the specified frequency bands.

30. The method according to p. 29, characterized in that the phase demodulation perform centering at least one narrow-band filter on the detected frequency bands of the signal data.

31. The method according to p. 30, characterized in that the frequency of each notch filter is determined at the detection step.

32. The method according to any of paragraphs.30 and 31, characterized in that the timing of the data signal in a narrow frequency bands determined during the discovery phase and use phase of Deych, at least one of these frequency bands detect the presence of signal data in multiple narrow frequency bands, the amplitude of the data signal in each band is compared with the normalized value, to determine the quality assessment of the data signal in each band.

34. The method according to p. 33, characterized in that the computation of the "center of gravity" performed by quality assessments to ensure that the Central frequency, and Central time for each flag sequence, the results of the calculation of the "center of gravity" is used in demodulation of the data signal.

35. The method according to any of paragraphs.29-34, wherein the data signal is passed through two sub-stages of detection and demodulation performed on each subchannel corresponding to the demodulated data signals are weighed and summed in accordance with the quality of the signals identified in the discovery phase.

36. The method according to any of paragraphs.29-35, wherein the received signal contains many narrowband data signals, each of which occupies a separate portion of the channel, and the receiver accepts these narrowband data signals simultaneously.

37. The method according to any of paragraphs.29-36, wherein after to the of the action scene, the data signal contains a data packet after a flag sequence of digits, and the detection step detects the presence of the flag sequence.

39. The method according to p. 38, characterized in that a separate narrow band of frequencies is compared with the desired flag signal at regular intervals.

40. The method according to any of paragraphs.38 and 39, characterized in that the packet data is passed between the initial and tail flag sequences and the detection step performs the detection of the two flag sequences.

41. The method according to p. 40, characterized in that to check the availability of the data packet detect both primary and tail flag sequence.

42. The method according to any of paragraphs.38-41, wherein the data signal has many data packets are separated from one another flag sequences.

43. The method according to any of paragraphs.36-42, wherein the step of detecting the presence of data signals in a separate narrow frequency bands perform detection flag sequence into multiple narrow frequency bands, the amplitude of the bits of the flag sequence in each band is compared with the normalized value to determine a quality assessment of RA is the frequency and time.

44. The method according to p. 43, characterized in that the computation of the "center of gravity" performed by quality assessments to ensure that the Central frequency, and Central time for each flag sequence, the results of a calculation of the "center of gravity" is used in demodulation of the data.

45. A receiver for reception and demodulation of narrow-band data signal transmitted at a frequency within a known frequency range containing means for demodulating the detected signal data, wherein the data signal is escapology signal of unknown frequency, in that it includes a means of sharing the frequency band into multiple frequency bands, each of which has a width smaller than the error rate of the data signals, and means for detecting the presence of the data signal in at least one of the specified frequency bands.

46. The receiver on p. 45, characterized in that it contains an analog-to-digital Converter (ADC), and the sharing tool contains a fast Fourier transform (FFT).

47. The receiver according to any one of paragraphs.45 and 46, characterized in that the demodulation means includes a filter adapted to pass only the Central frequency determined is selenia, detection and demodulation provided by the digital signal processor.

49. The receiver according to any one of paragraphs.45-48, characterized in that it contains means for detection and demodulation to detect and demodulate data transmitted in two subchannels, and further comprises means addition for weighting and summing the respective demodulated data signals in accordance with signal quality, specific detection.

50. The receiver according to any one of paragraphs.45-49, characterized in that the means for detecting the presence of a data signal in a narrow frequency bands includes means for comparing the amplitude of the data signal in each band with a normalized value to determine the quality assessment of the data signal in each band.

 

Same patents:

The invention relates to the field of radio communications and computing, and more particularly to methods and devices for data transmission in the computer network by radio with pseudorandom change the operating frequency

The invention relates to electrical engineering and can be used in communication systems with pseudorandom change the operating frequency

The invention relates to radio

The invention relates to electrical engineering and can be used in the communication system with signal transmission in a wide range, in particular to the actions of search honeycomb performed by the mobile station, and to receive specific honeycomb long code used in the communication system in a wide range

The invention relates to a communication system, multiple access, code-division multiplexing (mdcr)

The invention relates to a method of controlling a communications network, and the network contains a number of stations that can transmit data and receive data from each other

The invention relates to the field of radio and may find application in communication systems with pseudorandom change the operating frequency

The invention relates to radio communications and can find application in communication systems with broadband signals

Radio receiver // 2210859
The invention relates to the field of radio and can be used in telemetry systems for information from moving objects

FIELD: radio engineering; construction of radio communication, radio navigation, and control systems using broadband signals.

SUBSTANCE: proposed device depends for its operation on comparison of read-out signal with two thresholds, probability of exceeding these thresholds being enhanced during search interval with the result that search is continued. This broadband signal search device has linear part 1, matched filter 2, clock generator 19, channel selection control unit 13, inverter 12, fourth adder 15, two detectors 8, 17, two threshold comparison units 9, 18, NOT gates 16, as well as AND gate 14. Matched filter has pre-filter 3, delay line 4, n attenuators, n phase shifters, and three adders 7, 10, 11.

EFFECT: enhanced noise immunity under structural noise impact.

1 cl, 3 dwg

FIELD: radio engineering for radio communications and radar systems.

SUBSTANCE: proposed automatically tunable band filter has series-connected limiting amplifier 1, tunable band filter 2 in the form of first series-tuned circuit with capacitor whose value varies depending on voltage applied to control input, first buffer amplifier 3, parametric correcting unit 4 in the form of second series-tuned circuit incorporating variable capacitor, second buffer amplifier 5, first differential unit 6, first amplitude detector 7, first integrating device 9, and subtraction unit 9. Inverting input of subtraction unit 9 is connected to reference-voltage generator 10 and output, to control input of variable capacitors 2 and 4. Automatically tunable band filter also has series-connected second amplitude detector 11, second integrating unit 12, and threshold unit 13. Synchronous operation of this filter during reception and processing of finite-length radio pulses is ensured by synchronizer 14 whose output is connected to units 10, 8, and 12. This automatically tunable band filter also has second differential unit whose input is connected to output of buffer amplifier 3 and output, to second control input of variable capacitor of band filter 2.

EFFECT: enhanced noise immunity due to maintaining device characteristics within wide frequency range.

1 cl, 1 dwg

FIELD: radio communications engineering; mobile ground- and satellite-based communication systems.

SUBSTANCE: proposed modulator that incorporates provision for operation in single-channel mode with selected frequency modulation index m = 0.5 or m = 1.5, or in dual-channel mode at minimal frequency shift and without open-phase fault has phase-shifting voltage analyzer 1, continuous periodic signal train and clock train shaping unit 2, control voltage shaping unit 3 for switch unit 3, switch unit 3, switch unit 4, two amplitude-phase modulators 5, 6, phase shifter 7, carrier oscillator 8, and adder 9.

EFFECT: enlarged functional capabilities.

1 cl, 15 dwg

FIELD: electronic engineering.

SUBSTANCE: device has data processing circuit, transmitter, commutation unit, endec, receiver, computation unit, and control unit.

EFFECT: high reliability in transmitting data via radio channel.

4 dwg

FIELD: electronic engineering.

SUBSTANCE: method involves building unipolar pulses on each current modulating continuous information signal reading of or on each pulse or some continuous pulse sequence of modulating continuous information code group. The number of pulses, their duration, amplitude and time relations are selected from permissible approximation error of given spectral value and formed sequence parameters are modulated.

EFFECT: reduced inetrsymbol interference; high data transmission speed.

16 cl, 8 dwg

FIELD: communication system transceivers.

SUBSTANCE: transceiver 80 has digital circuit 86 for converting modulating signals into intermediate-frequency ones. Signal source 114 transmits first periodic reference signal 112 at first frequency. Direct digital synthesizer 84 receives second periodic signal 102 at second frequency from first periodic reference signal. Converter circuit affording frequency increase in digital form functions to convert and raise frequency of modulating signals into intermediate-frequency digital signals using second periodic signal 102. Digital-to-analog converter 82 converts intermediate-frequency digital signals into intermediate-frequency analog signals using first periodic reference signal 112.

EFFECT: reduced power requirement at low noise characteristics.

45 cl, 3 dwg

FIELD: radio engineering; portable composite phase-keyed signal receivers.

SUBSTANCE: proposed receiver has multiplier 4, band filter 6, demodulator 8, weighting coefficient unit 5, adding unit 7, analyzing and control unit 10, synchronizing unit 3, n pseudorandom sequence generators 21 through 2n, decoder 1, and switch unit 9. Receiver also has narrow-band noise suppression unit made in the form of transversal filter. Novelty is that this unit is transferred to correlator reference signal channel, reference signal being stationary periodic signal acting in absence of noise and having unmodulated harmonic components that can be rejected by filters of simpler design than those used for rejecting frequency band of input signal and noise mixture. Group of synchronized pseudorandom sequence generators used instead of delay line does not need in-service tuning.

EFFECT: facilitated realization of narrow-band noise suppression unit; simplified design of rejection filters.

1 cl, 8 dwg

FIELD: mobile radio communication systems.

SUBSTANCE: proposed method and device are intended to control transmission power levels for plurality of various data streams transferred from at least one base station to mobile one in mobile radio communication system. First and second data streams are transmitted from base station and received by mobile station. Power-control instruction stream is generated in mobile station in compliance with first or second data stream received. Power control signal is shaped in mobile station from first power control instruction stream and transferred to base station. Received power control instruction stream is produced from power control signal received by base station; power transmission levels of first and second data streams coming from base station are controlled in compliance with power control instruction stream received. In this way control is effected of transmission power levels of first data stream transferred from each base station out of first active set to mobile station and of transmission power levels of second data stream which is transferred from each base station out of second active set to mobile station.

EFFECT: enlarged functional capabilities.

80 cl, 21 dwg

FIELD: radio engineering.

SUBSTANCE: proposed method and device designed for fast synchronization of signal in wade-band code-division multiple access (WCDMA) system involve use of accumulations of variable-length samples, testing of decoder estimates for reliability, and concurrent decoding of plurality of sync signals in PERCH channel. Receiver accumulates samples required for reliable estimation of time interval synchronization. As long as time interval synchronization estimates have not passed reliability tests, samples are accumulated for frame synchronization estimates. As long as frame synchronization estimates have not passed reliability tests, samples are analyzed to determine channel pilot signal shift.

EFFECT: reduced time for pulling into synchronism.

13 cl, 9 dwg

FIELD: satellite navigation systems and may be used at construction of imitators of signals of satellite navigational system GLONASS and pseudo-satellites.

SUBSTANCE: for this purpose two oscillators of a lettered frequency and of a fixed frequency are used. Mode includes successive fulfillment of the following operations - generation of a stabilized lettered frequency, its multiplication with an oscillator's fixed frequency and filtration of lateral multipliers with means of filters of L1 and L2 ranges and corresponding option of a fixed and a lettered frequencies.

EFFECT: reduces phase noise and ensures synthesizing of lettered frequencies of L1 and L2 ranges of satellite navigational system from one supporting generator at minimum number of analogous super high frequency units.

3 cl, 1 dwg

Up!