RU71491U1 - DEVICE FOR TRANSMISSION AND RECEIVING OF DISCRETE INFORMATION IN A RADIO LINE WITH A PSEUDO-RANDOM RESETTING OF THE OPERATING FREQUENCY - Google Patents

Abstract

The invention relates to the field of communication technology with pseudo-random tuning of the operating frequency and can be used to transmit discrete information protected by a noise-resistant code. The technical result consists in increasing the noise immunity of the communication, improving the distribution (uniformity of use) of the operating frequencies with a small number of them. To do this, information from the output of the encoder is accumulated in a block, the volume of which is selected in accordance with the type of code used, the speed of information transmission in the channel and the duration of operation at one working frequency, alternated with a grouping of characters according to serial numbers in the code word and transmitted to the communication channel one at a time group at one working frequency without repeating the working frequency on the transmission interval of the block. On the receiving side, the symbols of the received information packet are de-interleaved and PC words are received, which are decoded with error detection and correction. A pseudo-random sequence generator (PSP) is introduced on the transmitting side of the device, and a PSP generator is introduced on the receiving side.

Description

The alleged invention relates to the field of radio communications, can be used to transmit discrete information protected by an error-correcting code in radio communication systems with pseudo-random tuning of the operating frequency (MHF).

Signal transfer in the frequency hopping mode is described in detail in the literature, in particular in [1].

A known method of transmitting information using interleaving, according to which the quality of the communication channel is first assessed (for example, by noise and interference levels, fading duration, etc.) and the value of the interleaving depth of the word symbols of the error-correcting code is selected. Then, the word symbols of the error-correcting code are interleaved and an information packet composed of symbols of several words of the error-correcting code is received, which is transmitted to the communication channel. On the receiving side, the symbols are first de-interleaved in the information packet and the error-correcting code words included in the information packet are obtained. Then the words of the error-correcting code are decoded with the detection and correction of errors [2].

A known method of transmitting information using adaptive interleaving of characters, in which continuous quality control of the communication channel is carried out. Based on the results of the quality control of the communication channel, the value of the depth of interleaving of the words of the error-correcting code is selected, the symbols of the words of the error-correcting code are interleaved, and an information packet composed of the symbols of several words of the error-correcting code is obtained. Next, the information packet is transmitted to the communication channel. On the receiving side, the symbols of the received information packet are deinterleaved first and the words are received

error-correcting code included in the information package. Then the words of the error-correcting code are decoded with the detection and correction of errors [3].

The disadvantages of the known methods are the need to evaluate the channel, the impossibility of maintaining a constant delay in the delivery of information, low noise immunity from concentrated on the frequency of interference, unwarranted uniformity of frequency distribution with a small number.

A known method of transmitting discrete information in a radio line with a pseudo-random tuning of the operating frequency, including at the transmitting end dividing the input signal into blocks formed as a sequence of binary vectors, tuning the frequency of the transmitter in accordance with the binary code of the pseudorandom sequence created by the feedback shift register, modulation the frequency of the transmitter and the subsequent radiation of the signal into space, receiving a signal at the receiving end of the radio line simultaneously at all hours frequency, signal conversion to an intermediate frequency, amplification, demodulation and signal supply to the terminal device [4].

The disadvantages of this method are the need to receive simultaneously at all frequencies, low noise immunity from concentrated on the frequency of interference, not guaranteed uniform distribution of frequencies with a small number of them.

Closest to the technical nature of the proposed is a method of transmitting signals in the frequency hopping mode, presented in [5], adopted as a prototype.

The prototype method is as follows. Continuous monitoring of the quality of the communication channel is carried out, according to the results of which the value of the depth of interleaving of the characters of the words of the error-correcting code (PC) is selected, interleaving of the characters of the PC, the words of the PC and the information package composed of several characters

PC words are transmitted to the communication channel, on the receiving side, the symbols of the received information packet are de-interleaved and PC words are received, which are decoded with error detection and correction, while the quality of the communication channel is estimated from the results of decoding of PC words, and the average number of errors in PC words is estimated , determine the selective variance of the number of errors in the words of the PC of the received information packet, and after receiving the next information packet, the previous value of the interleaving depth is changed by off the increase in the sample variance of the distribution of errors in the words of the received information packet from the variance of the binomial distribution law.

The disadvantage of the prototype method are: inconsistent delay in the delivery of information, which varies depending on the interference environment, low noise immunity from concentrated on the frequency of interference, not guaranteed uniformity of frequency distribution with a small amount.

A method for transmitting and receiving information in systems with frequency hopping, free from these disadvantages.

To eliminate these shortcomings in the method of transmitting and receiving information in a radio line with a pseudo-random tuning of the operating frequency using interleaving, which consists in the fact that the symbols of the error-correcting code (PC) are interleaved on the transmitting side and an information packet composed of several PC words is transmitted to the channel of communication, on the receiving side, the symbols of the received information packet are de-interleaved and PC words are received that decode with error detection and correction, according to Bretenoux as PCs use a block character code information on the transmission side encoder after PC accumulated in the volume N × M, where N - codeword size in symbols, M, M≥1 - interleaving depth in codewords,

alternation of the accumulated information is performed symbolically with a grouping of characters with the same sequence numbers in code words into groups of M characters, each group is transmitted at a frequency that does not coincide with other frequencies in the transmission interval of information stored in the interleaver.

The key point of the invention is an integrated approach to the selection of parameters of three main components at once: an encoder, an interleaver, and a bandwidth generator.

The proposed method for transmitting and receiving discrete information in a radio channel with a pseudo-random tuning of the operating frequency consists in transmitting information using error-correcting coding, interleaving the symbols of the error-correcting code, and transmitting data to the communication channel with frequency hopping. On the receiving side, information is received, the symbols are de-interleaved, and the words of the error-correcting code are received. Then the error-correcting code words are decoded with error detection and correction. The choice of PC, the structure of the interleaver of the law of forming the sequence of frequency tuning is carried out comprehensively taking into account the features of the communication system with frequency hopping.

The block symbol code is used as a PC, the information after the PC encoder is accumulated in the volume N × M, where N is the size of the code word in characters, M is the depth of interleaving in code words (M≥1), the information accumulated in the interleaver is interleaved symbolically with grouping characters in groups of M characters with the same sequence numbers in the code words, the transmission of each group is carried out at a frequency that does not coincide with the others in the transmission interval of the block.

The number of frequencies can be any, but it is recommended to choose it equal to (or more) the number of characters of the error-correcting code N used in the communication system. The alternation and transmission of data in the communication channel with frequency hopping is performed so that the characters of one code

words were transmitted at mismatched operating frequencies. The duration of the transmission interval at one frequency is determined based on the requirements of the system, and a multiple of the transmission duration of one code symbol is selected. The volume of the interleaver is determined by the size of the symbol of the error-correcting code and the number of characters sequentially transmitted at one operating frequency for one clock frequency hopping frequency.

The proposed method is carried out in the following sequence:

1. The input information is fed to the input of the error-correcting code encoder.

2. From the output of the encoder, information is accumulated in the interleaver. The amount of information accumulated in the interleaver is at least one codeword.

3. The information accumulated in the interleaver is shuffled according to the interleaving algorithm: characters with the same sequence numbers inside the code word are grouped together. The permutation algorithm is shown in figure 1.

4. After the interleaver, information is sequentially transmitted in groups of symbols to the transmitter with frequency hopping, which transmits each group at frequencies that are not repeated in the transmission interval of the information stored in the interleaver. The frequency tuning sequence is carried out according to the pseudo-random law. Figure 2 shows the time-frequency matrix of work for four frequencies (F1, F2, F3, F4) and the size of the code word PC, equal to four characters.

5. At the receiving end, information is received. The receiver synchronizes the SRP with the transmitting side in one of the known ways.

6. The received information is received at the input of the deinterleaver, where it is accumulated in an amount equal to the volume of the interleaver on the transmitting side.

7. The deinterleaver performs a reverse permutation of characters.

8. The data from the deinterleaver are fed to the input of the error-correcting code decoder, where errors are detected and corrected.

The proposed method increases the noise immunity of radio communication systems with frequency hopping, provides a time constant for the delivery of information, does not require a reverse communication channel, improves the uniformity of the statistical distribution of frequencies when working on a small number of frequencies allocated for operation.

A channel transmitter is known for a code division multiple access (CDMA) communication system using at least two carriers, comprising a channel encoder for encoding channel transmitted data into symbols at a predetermined coding rate, a channel controller for generating a symbol distribution signal in accordance with a predetermined configuration of the symbol deletion matrix, wherein the configuration of the symbol deletion matrix is determined so that redelyat characters relevant carrier with minimal deterioration of the characteristics even if a particular carrier is distorted, and symbol distributor for receiving the symbols and distributing received symbols for the carrier according to the symbol distribution signal [6].

The disadvantages of this device are low noise immunity, the need for reception simultaneously at all frequencies.

The closest in technical essence to the proposed is a device that uses interleaving and transmit diversity by reordering the sequence of characters transmitted in different transmission channels [7], adopted as a prototype.

We enlarge the prototype block diagram as follows.

The enlarged block diagram of the prototype differs from the original in the following positions: the frame shaper is combined with the PC encoder and the frame check block is combined with the PC decoder as non-essential, in the first transmission channel the Walsh expander and GES expander are combined into one block of the converter 12, in the second transmission channel the Walsh expander, the PS expander and the unit у are combined into one converter unit 15, on the receiving side in the first reception channel, the search unit, the PS demodulator, the Walsh compression unit are combined into the processing unit 18 and, in the second reception channel, the PS demodulator and the Walsh compression unit are combined in the processing unit 19.

An enlarged block diagram of the prototype device is shown in figure 3, where it is indicated:

on the transmitting side - 1 - PC encoder; 2, 13 - interleavers; 3, 16 - transmitters; 4, 17 - antennas; 11 - demultiplexer; 12, 15 - converters; 23, 24 - transmitting subsystems; 14 - block shuffle;

on the receiving side - 5 - antenna; 6 - receiver; 7, 21 - inverted interleavers; 8 - decoder; 18, 19 - processing units; 20 - block shuffle; 22 - multiplexer.

The prototype device contains on the transmitting side a series-connected encoder PC 1 and a demultiplexer 11, a series-connected interleaver 2., and a transmitting subsystem 23, consisting of a series-connected converter 12 and a transmitter 3, the output of which is connected to the antenna 4, and also a series-connected interleaver 13 Shuffle block 14 and transmitting subsystem 24, consisting of series-connected transducer 15 and transmitter 16, the output of which is connected to antenna 17. Moreover, the inputs of interleavers 2 and 13 under oedineny to the output of the demultiplexer 11.

On the receiving side is a series-connected antenna 5, receiver 7, processing unit 18, inverted interleaver 7,

multiplexer 22 and decoder PC 8, the output of which is the output of the device. In addition, the processing unit 19, the shuffling unit 20 and the inverted interleaver 21, the output of which is connected to the other input of the multiplexer 22, are connected in series. Moreover, the output of the receiver 6 is connected to the first input of the processing unit 19, the second input of which is connected to the output of the processing unit 18.

The prototype device works as follows.

On the transmitting side, the incoming information is fed to the encoder PC 1, which adds the codes of direct error correction to the data stream. After encoding, the data is processed by the demultiplexer 11, which distributes the symbols encoded with error correction into different groups, each of which is processed separately before transmission. Although FIG. 3 shows the use of two groups, those skilled in the art will understand that the demultiplexer 11 can distribute characters to the number of groups of more than two. Then each group of bits is processed by the interleavers 2 and 13, the signal from the output of the interleaver 2 is transmitted to the transmitting subsystem 23, which in the illustrated exemplary embodiment includes a converter 12 and a transmitter 3. The output signal of the interleaver 2 is supplied to the converter 12, from where the signal goes to the transmitter 3 which amplifies, upconverts and filters the signal for transmission through antenna 4.

The signal from the output of the interleaver 13 is supplied to the shuffle unit 14, which changes the sequence of data coming from the output of the interleaver 13. The output signal of the shuffle unit 14 is processed in much the same way as the unshuffled signal from the interleaver 2. Then the signal from the output of the shuffle unit 14 is fed to the transmitting subsystem 24 to the converter 15. The signal from the converter 15 enters the transmitter 16, which amplifies, converts with increasing frequency and filters the signal for transmission through the antenna 17.

At the receiving side, the signal is received through the antenna 5 and processed by the receiver 6. Then, the received signals are processed by the processing units 18 and 19. The processing unit 18 demodulates the signal that has been received through the transmission channel. Reversed interleaver 9 receives a demodulated signal and performs the reverse interleaving of the signal. The processing unit 19 demodulates the signal that has arrived on the transmission channel. In the processing unit 19, the result of the processing unit 18 is taken into account. Then the output signal of the processing unit 19 is processed by the batch unit 20 and fed to the inverted interleaver 21. The inverted interleaver 21 performs the opposite function of the interleaver 13.

The multiplexer 22 performs the opposite operation of the demultiplexer 11 to form a single data stream. The resulting single data stream is processed by the PC 8 decoder.

The disadvantages of the prototype device are low noise immunity, as well as the need to receive simultaneously at all frequencies.

To eliminate these shortcomings, a device for transmitting and receiving an information signal, comprising a PC encoder, an interleaver and a transmitter, the output of which is connected to a transmitting antenna, and a receiving antenna, a receiver, as well as a reversed interleaver and a PC decoder, are output on the receiving side which is the output of the device according to the invention, a pseudo-random sequence generator (PSP) is introduced on the transmitting side, the output of which is connected to the second input of the transmitter, In this case, the output of the PC encoder is connected to the input of the interleaver, the output of which is connected to the input of the transmitter, on the receiving side is the PSP generator, the output of which is connected to the second input of the receiver, in addition, the output of the receiver is connected to the input of the inverted interleaver, the output of which is connected to the input of the PC decoder , and

PC encoder, interleaver, PSP generator on the transmitting side and PSP generator, inverted interleaver, PC decoder on the receiving side are made in the form of a microprocessor device with the corresponding software.

A block diagram of the proposed device is shown in figure 4, where it is indicated: 1 - PC encoder, 2 - interleaver, 3 - transmitter, 4 - transmitting antenna, 5 - receiving antenna, 6 - receiver, 7 - inverted interleaver, 8 - PC decoder , 9 - PSP generator on the transmitting side, 10 - PSP generator on the receiving side.

The proposed device comprises, on the transmitting side, a PC 1 encoder, an interleaver 2, a transmitter 3, and an antenna 4 connected in series. The second input of the transmitter 3 is connected to the output of the PSP 9 generator. On the receiving side, a antenna 5, a receiver 6, a deinterleaver 7, and a PC decoder are connected in series 8., the output of which is the output of the device .. To the second input of the receiver 6 is connected the output of the generator PSP 10.

The proposed device operates as follows.

The incoming information is fed to the encoder of PC 1. As a PC, a block character code with a codeword size N, measured in characters, is used. From the output of encoder 1, information is fed to the input of interleaver 2, in which information is accumulated in the volume N × M, where N is the size of the codeword in characters, M is the interleaving depth (M≥1) in codewords. The information accumulated in the interleaver 2 is interleaved symbolically with the grouping of characters in groups of M characters with the same serial numbers in code words. From the output of the interleaver 2, the information goes to the input of the transmitter 3, to the second input of which the SRP is supplied from the SRP 9 generator, which forms the SRP, on the basis of which the operating frequencies of the transmitter 3 are changed. The SRP 9 generator and the interleaver 2 are synchronized so that the transmission of each group characters with the same

serial numbers in the code words is carried out at a frequency that does not coincide with other frequencies in the transmission interval of data stored in the interleaver 2. The signal from the output of the transmitter 3 is emitted using the antenna 4.

At the receiving side, information is received: the signal from the antenna 5 is fed to the input of the receiver 6. At the second input of the receiver 6, a signal of the SRP from the generator of the SRP 10, which is synchronized with the generator of the SRP 9 in one of the known ways. Reception is carried out at frequencies determined by the output PSP of the PSP generator 10. From the output of the receiver 6, the information is transmitted to the inverted interleaver 7. In the inverted interleaver 7, information is inverted to the conversion performed by the interleaver 2. From the output of the inverted interleaver 7, the information is transmitted to the input of PC 8 decoder where error detection and correction is carried out. The information received is output from the output of the PC 8 decoder.

The number of operating frequencies, which determines the range of values of the PSP generators 9 and 10, is selected to be equal to (or more) the number of characters of the code word of the error-correcting code of the PC encoder 1. The duration of the transmission interval at one frequency by transmitter 3 is determined by the volume of interleaver 2 and is equal to the time interval for which the transmission occurs all characters with the same sequence numbers in the code word accumulated in the interleaver 2.

PC encoder 1, interleaver 2, PSP 9 and 10 generators, inverted interleaver 7, and PC 8 decoder can be implemented in one of the following ways:

- in the form of microprocessor devices (or as a single microprocessor device) with appropriate software, for example, a processor series TMS320VC5416 from Texas Instruments,

- in the form of a programmable logic integrated circuit (FPGA), with the appropriate software, for example, Xilinx FPGA XCV400,

- in the form of specialized microcircuits.

The technical result is to increase the noise immunity of radio communication systems with frequency hopping, as well as the simultaneous reception at the same frequency at any time.

Literature.

[1] Borisov V.I. and others. "Interference immunity of radio communication systems with the expansion of the signal spectrum by the method of pseudo-random tuning of the operating frequency" - M .: Radio and communication, 2000. - 384 p.

[2] Elements of the theory of transmission of discrete information. Ed. L.P. Purtova. M .: Communication, 1972, p. 149.

[3] Zlotnik B.M. Immunity Codes in Communication Systems. M .: Radio and communications, 1989, p. 218.

[4] RU 2215370 C1, 10.27.2003

[5] RU 2265960 C2, 10.20.2002 - prototype.

[6] RU 2000130302 A, 10.20.2002

[7] RU 2252484 C2,12.04.2000 - prototype.

Claims (2)

1. A device for transmitting and receiving an information signal, comprising on the transmitting side an error-correcting code (PC) encoder, an interleaver and a transmitter whose output is connected to the transmitting antenna, on the receiving side, a receiving antenna, a receiver, as well as a reversed interleaver and a PC decoder, are connected in series, the output of which is the output of the device, characterized in that a pseudo-random sequence generator (PSP) is introduced on the transmitting side, the output of which is connected to the second input of the transmitter, while the output the PC encoder is connected to the input of the interleaver, the output of which is connected to the input of the transmitter, on the receiving side is the PSP generator, the output of which is connected to the second input of the receiver, in addition, the output of the receiver is connected to the input of the inverted interleaver, the output of which is connected to the input of the PC decoder, the encoder The PC, the interleaver, the PSP generator on the transmitting side and the PSP generator, the inverted interleaver, the PC decoder on the receiving side are made in the form of a microprocessor device with the appropriate software or programmer Mykh logic integrated circuits. 2. A device for transmitting and receiving an information signal, comprising a PC encoder, an interleaver and a transmitter, the output of which is connected to a transmitting antenna, on a receiving side, a receiving antenna, a receiver, as well as a reversed interleaver and a PC decoder, whose output is an output devices, characterized in that a pseudo-random sequence generator (PSP) is introduced on the transmitting side, the output of which is connected to the second input of the transmitter, while the output of the PC encoder is connected to the input ohm interleaver, the output of which is connected to the input of the transmitter, on the receiving side is a PSP generator, the output of which is connected to the second input of the receiver, in addition, the output of the receiver is connected to the input of the inverted interleaver, the output of which is connected to the input of the PC decoder, the PC encoder, interleaver, reverse interleaver, PSP generators, PC decoder are made on specialized microcircuits.