Method for packet transmission of messages in communication network using additional channels

Abstract

FIELD: radio engineering.SUBSTANCE: stations use modulation with a frequency shift and processing that ensures the quasi-orthogonality of any pair of harmonics used and, accordingly, the frequency division of the channels. Information symbols (IS) are formed as a sequence of different signals. The signals consist of the sum of several harmonics. The signals used to generate different IS differ in the values of the harmonic frequencies. The number of IS used for transmission over one channel is determined by the number of modulation positions. To form different communication channels, different IS are used. The total number of channels that can be used exceeds the established number of times the maximum number of communication lines through which information can be exchanged simultaneously. For the first transmission-reception cycles, IS are used, the numbers of which are determined in advance. At each reception of messages, the states of communication channels are analysed by calculating the values of the signal-to-noise ratio (SNR) and comparing the obtained SNR values with the established threshold value. If a decision is made that the information has not been received, the station increases the number of channels by the set value. Message transmission via additional channels is carried out using additional IS.EFFECT: transmitting messages with a given quality using additional communication channels in the presence of interference.1 cl, 6 dwg

Description

[0001] The proposed method relates to radio engineering and can find application in communications equipment.

[0002] A device for automatically determining radio communication channels with a maximum signal-to-noise ratio is known, described in Russian patent No. 133993, H04B1 / 10. The disadvantage of this method is the insufficiently high efficiency of transmitting messages over radio channels in the presence of interference.

[0003] A method and device for adaptive radio communication are described in Russian Patent No. 2284659, H04B7 / 005. In this method, the quality of a communication channel is assessed by comparing a control pattern signal, the level of which is varied within specified limits, with the same signal distorted by noise and interference at the receiving location. On each allocated communication frequency, the number of errors is calculated, the maximum transmission rate is determined, and the frequency that ensures the maximum transmission rate with the minimum signal is selected for communication. A disadvantage of this method is the insufficient efficiency of message transmission over radio channels in the presence of interference.

[0004] A method for two-way high-speed radio communication with efficient use of the radio frequency spectrum in a departmental communications system is described in RU Patent No. 2650191, H04B 7 / 00. This method selects the optimal communication frequency with a minimal level of additive interference from a corresponding group of optimal operating frequencies. A disadvantage of this method is its limited effectiveness in the presence of interference.

[0005] A method for two-way high-speed radio communication with efficient use of the radio frequency spectrum in a departmental communications system is described in RU Patent No. 2663200, H04B 7 / 00. This method selects the optimal communication frequency with a minimal level of additive interference from a corresponding group of optimal operating frequencies. A disadvantage of this method is its limited effectiveness in the presence of interference.

[0006] A method for transmitting real-time information with increased noise immunity over a local area network (aRTnet) is known, described in Russian Patent 2667387H04L 12 / 00. A disadvantage of this method is the insufficient efficiency of transmitting messages over radio channels in the presence of interference.

[0007] An improved method and device for transmitting information in a packet radio service is known under Russian Patent Application No. 2002103572H04Q 7 / 00. A disadvantage of this method is the insufficient efficiency of transmitting messages over radio channels in the presence of interference.

[0008] A method of packet transmission of messages according to the standard is known IEEE 802.11, the description of which is given in the article by S.A. Postnikov “Protocols of the data link and network layers for a distributed backbone network with time division of channels”, published in the journal “Theory and technology of radio communication”, issue 1, 2008, JSC “Concern “Sozvezdie”, the disadvantage of which is the insufficiently high efficiency of information exchange via radio channels in the presence of interference.

[0009] The closest analogue in technical essence to the proposed method is the method implemented by a communication station with adaptive channel switching, the description of which is given in the Russian Federation patent 2667387H04B 7 / 26, adopted as a prototype.

[0010] The prototype method is as follows.

[0011] When organizing data exchange between communication stations, continuous analysis of the state of all channels allocated for communication and storage of information about this, allocation for transmission, reception, analysis, joint processing of received signals of several frequency channels with maximum signal-to-noise ratios, both in the forward and reverse directions, formation of new communication plans, transmission of this information to the corresponding subscribers of the system, storage of it until degradation of the parameters of at least one of the operating radio channels, and transition to a new communication plan in the future are carried out.

[0012] The disadvantage of the prototype method is that additional channels are not used to transmit information to the subscriber in cases where the transmission of information via the channels used with the specified quality is not ensured.

[0013] The objective of the proposed method is to ensure the transmission of messages with a given quality using additional channels in the presence of interference.

[0014] To solve the stated problem in the method of packet transmission of messages in a communication network using additional channels, which consists in the fact that in communication stations a continuous analysis of the state of all channels allocated for communication and storage of information about this is carried out, allocation for transmission, reception, analysis, joint processing of received signals of several frequency channels, formation of new communication plans, transmission of this information to the corresponding subscribers of the system, storage of it until the degradation of the parameters of at least one of the operating radio channels, and transition to a new communication plan in the future, according to the invention, the stations operate in a "multipoint-multipoint" network,

[0015] The stations use frequency-shift modulation and processing that ensures quasi-orthogonality of any pair of used harmonics and, accordingly, ensures frequency division of the channels, while the difference in the frequency values ​​of any pair of adjacent harmonics exceeds the established threshold value;

[0016] information symbols are formed as a sequence of different signals, the signals consist of the sum of several harmonics, the signals used to form different information symbols differ in the values ​​of the harmonic frequencies that form the signals,

[0017] The number of information symbols used for transmission over one channel is determined by the number of modulation positions;

[0018] information symbols are numbered in the established manner;

[0019] Different information symbols are used to form different communication channels, the total number of channels that can be used exceeds the established number of times the maximum number of communication lines through which simultaneous information exchange can be carried out in the communication network;

[0020] at the stage of establishing communication, perform synchronization;

[0021] set the minimum required signal power value for each communication line; when establishing a connection with several radio stations, the output signal power value is set equal to the maximum value, which is selected from the signal power values ​​simultaneously transmitted by the station;

[0022] stations exchange service and user information; for the first cycles of receiving and transmitting messages, they use information symbols, the numbers of which are determined in advance; their number and the number of channels are determined using a priori information about the possible values ​​of interference parameters;

[0023] At each message reception, the communication channel states are analyzed by measuring the values ​​of the sum of the powers of the interference and the signal and interference in the corresponding frequency bands, calculating the values ​​of the signal-to-noise ratio (SNR) at the message reception point, and comparing the obtained SNR values ​​with the established threshold value;

[0024] If it is decided that the information is not received, the station transmits the corresponding code signal to another station;

[0025] at the transmitting station, upon receiving this code signal, the number of channels and, accordingly, the number of information symbols used to transmit information are increased by the set value;

[0026] in the next cycle of message transmission and reception, the information not received by the other party and new numbers of the information symbols used - additional symbols - are retransmitted;

[0027] If the transmitting station has not received information about the reception of information by another station, transmission is carried out using additional information symbols;

[0028] The process continues until the transmitting station receives a message about the reception of the transmitted information by another station, or until all additional information symbols that can be allocated in the station at a given time are exhausted.

[0029] The proposed method for packet transmission of messages in a communication network using additional channels is as follows.

[0030] The stations operate in a point-to-multipoint network.

[0031] The stations use frequency-shift modulation and processing that ensures quasi-orthogonality of any pair of harmonics used and, accordingly, ensures frequency division of channels, while the difference in harmonic frequency values ​​exceeds the established threshold value (F р). An illustrative example is shown in Fig. 1.

[0032] Quasi-orthogonality of any pair of harmonics used can be ensured by using the signal processing method described in Russian patent No. 2709182, H04B 1 / 10, which is as follows.

[0033] After multiplying the additive sum of the signal and noise (hereinafter referred to as the sum of the signal and noise) in the corresponding multiplication blocks by the sine and cosine components of any harmonic—the reference signals—the processing of the multiplication results is performed identically in the corresponding lines. Each of the resulting signals is split into two identical components. The first component is filtered by a low-pass filter (LPF), the bandwidth of which is matched to the signal bandwidth. Simultaneously, the second component is filtered by a band-pass filter, the passband of which is selected such that the upper frequency of the band-pass filter corresponds to the upper frequency of the signal, and the lower frequency of the band-pass filter is set as close as possible to zero.The selection of the low-pass filter and band-pass filter is carried out so that the amplitude-frequency response (AFR) of the band-pass filter in the frequency range close to zero has the maximum possible slope, and in the frequency range starting from the value for which the difference in the AFR values ​​of the low-pass filter and band-pass filter becomes less than some predetermined value, their AFRs are ensured to be identical to the maximum degree. An illustrative example is shown in Fig. 1.

[0034] The signals that pass through the low-pass and band-pass filters are subtracted from each other. The subtraction result is converted to digital form. Using these values, corresponding to the sine and cosine components of a single frequency, the power of the sum of the harmonics and interference for each harmonic is determined by summing their squares. These values, proportional to the power of the sum of the signal and interference, are stored.

[0035] P сп = P с +P кос , (1)

[0036] where P сп , P с , P кос- values ​​proportional to the power of the sum of the signal and interference, the power of the signal and the power of the combination components of the reference signal and interference, respectively.

[0037] This value is considered as an estimate of the signal power, since the values ​​proportional to the combination components have different signs and, accordingly, their sum has a small value.

[0038] Calculate the power of each signal by summing the power values ​​calculated for the harmonics that make up the signal.

[0039] Information symbols (IS) are formed as a sequence of different signals. The signals consist of the sum of several harmonics. The signals used to form different IS differ in the frequencies of the harmonics that make up the signals.

[0040] The power of the INS is calculated by summing the power values ​​of the signals that form it.

[0041] The number of INS used for transmission on one channel is determined by the number of modulation positions.

[0042] Ins are numbered arbitrarily.

[0043] Different I / Cs are used to transmit messages in different communication channels.

[0044] The total number of channels that can be used exceeds the maximum number of communication lines that can simultaneously exchange information in the communication network by a factor of 4–5, for example. The total number of channels used is determined through mathematical modeling.

[0045] Synchronization is performed during the connection establishment stage.

[0046] When using the signal processing method described in Russian Federation Patent No. 2709182, H04B 1 / 10, a sufficient level of synchronization accuracy is ensured by using clock synchronization (see, for example, the description given in the book “Fundamentals of the Theory of Radio Engineering Systems. Tutorial. / / V.I. Borisov, V.M. Zinchuk, A.E. Limarev, N.P. Mukhin. Ed. by V.I. Borisov. Voronezh Research Institute of Communications, 2004”, pp. 222, 223).

[0047] Sets the minimum required signal power for each communication line, for example, by establishing a connection using the maximum signal power and then exchanging messages with the signal power reduced by a set amount. The minimum required output signal power level is established to improve the reliability of communication equipment, enhance electromagnetic compatibility (EMC) characteristics, and enhance signal security.

[0048] The minimum required radiated power is the minimum power required to ensure a specified level of information transmission quality. Information transmission quality can be assessed, for example, by comparing the calculated SNR value with the corresponding threshold.

[0049] The minimum required radiated power values ​​are set, for example, by a straightforward enumeration method, starting with the maximum value. The next value is obtained by decreasing the current value by the set amount.

[0050] When exchanging information with multiple radio stations, the signal output power value is set to the maximum value selected from the signal power values ​​simultaneously transmitted by the station.

[0051] The stations exchange service and user information. For the first message transmission and reception cycles, they use ISNs whose numbers are predetermined. Their number and the number of channels are determined using a priori information about the possible values ​​of interference parameters.

[0052] At each message reception, the communication channel states are analyzed by measuring the values ​​of the sum of the powers of the interference and the signal and interference in the corresponding frequency bands, calculating the values ​​of the signal-to-noise ratio (SNR) at the message reception point, and comparing the obtained SNR values ​​with the established threshold value.

[0053] The interference power is estimated using a method and device for isolating signals in the presence of interference, the description of which is given in patent RU No. 2675386, H04B 1 / 10 as follows.

[0054] The mixture of signal and interference is multiplied by a reference signal, the frequency value of which is set so that the value of the difference (sum) frequency of the analyzed harmonic and the reference signal becomes equal to the value of the central frequency of the bandpass filter of the additional channel, the frequency band value of which is equal to the doubled frequency value (F Р), starting from the value of which the difference between the frequency response values ​​of the low-pass filter and the band-pass filter becomes less than a certain predetermined value. An illustrative example is shown in Fig. 1.

[0055] The signal passing through the bandpass filter output is squared. The resulting signal is split into two equal components. The first component is filtered by a lowpass filter (LPF), the bandwidth of which is matched to the bandwidth of the bandpass filter of the additional channel. Simultaneously, the second component is filtered by a bandpass filter, the passband of which is selected such that the upper frequency of the bandpass filter corresponds to the difference between the upper and lower frequencies of the bandpass filter of the additional channel; the lower frequency of the bandpass filter is set as close to zero as possible.The selection of the low-pass filter and band-pass filter is carried out so that the amplitude-frequency response (AFR) of the band-pass filter in the frequency range close to zero has the maximum possible slope, and in the frequency range starting from the value for which the difference in the AFR values ​​of the low-pass filter and band-pass filter becomes less than some predetermined value, their AFRs are ensured to be identical to the maximum degree. An illustrative example is shown in Fig. 1.

[0056] The signals passing the low-pass and band-pass filters are subtracted from each other. The results of the subtraction are summed. The resulting value is proportional to the combined signal and interference power. The resulting value is proportional to the sum of the combined signal and interference components, the signal power, and the interference power.

[0057] P сп = P кс +P с +R п , (2)

[0058] where P кс P с , P п, - values ​​proportional to the power of the combined components of the signal and interference, the signal power and the interference power, respectively.

[0059] By subtracting from the sum of the values ​​of the proportional power of the combination components of the signal and interference, the signal power and the interference power (2), the sum of the values ​​of the signal power and the proportional power of the combination components of the reference signal and interference (1), we obtain

[0060] R по =R п + P кс - P кос . (3)

[0061] The value of the sum of the combination components of the reference signal and interference and the combination components of the signal and interference has a small value, since the terms of the sums have different signs, so this value can be considered as an estimate of the interference power (P по ).

[0062] Divide the value calculated using expression (1) by the value calculated using expression (3). The resulting value is considered as an estimate of the SNR value at the reception point of the transmitted messages.

[0063] Based on the results of simulation using the MATLAB system, it was found that the error in estimating the SNR value when using this method does not exceed 20% on average.

[0064] If the station determines that the information has not been received, it transmits a corresponding code signal to the other station. Upon receiving this code signal, the transmitting station increases the number of channels and, consequently, the number of I / Cs used for transmitting the information by a specified value—additional symbols.

[0065] Any unused InS from the list of symbols are selected as additional InS.

[0066] In the next cycle of message transmission and reception, the information not received by the other party and the numbers of the new InS are retransmitted.

[0067] If the transmitting station has not received information about the reception of information by another station, then transmission is carried out using additional symbols.

[0068] The information to be transmitted is divided into K streams, the volume of which is proportional to the data transfer rate in the corresponding channels. The duration of the ISS is increased so that the signal energy reaches the required level.

[0069] To transmit information in one channel, for example, a repetition coding method is used.

[0070] This value of the number of channels is determined, for example, by using the dependencies of the quality of message transmission on the SNR value, obtained by mathematical modeling, or by using analytical methods.

[0071] To solve the problem of selecting N information symbols that form K communication channels, an approach can be used, for example, that ensures that the SNR value exceeds the threshold value for each channel.

[0072] The process continues until the transmitting station receives a message about the reception of the transmitted information by the other station.

[0073] The technical result consists in increasing the efficiency of information exchange in a communication network in the presence of interference.

[0074] The structural diagram of the device implementing the proposed method of packet transmission of messages in a communication network using additional channels is shown in Fig. 2, where it is indicated:

[0075] 1 - antenna;

[0076] 2 - wideband filter (WBF);

[0077] 3 - high frequency amplifier (HFA);

[0078] 4.1, 4.2, 4.3 - first, second and third mixers;

[0079] 5.1, 5.2, 5.3 - first, second and third frequency synthesizers (MF);

[0080] 6 - transmitter;

[0081] 7.1, 7.2, 7.3 - first, second and third bandpass filters (BPF);

[0082] 8.1, 8.2 - the first and second intermediate frequency amplifiers (IFA);

[0083] 9 - demodulator;

[0084] 10 - decoder;

[0085] 11 - synchronization block;

[0086] 12 - analog-to-digital converter (ADC);

[0087] 13 - computing device (CD);

[0088] 14 - block for measuring the power of the sum of interference and signal (SISP);

[0089] 15 - control device;

[0090] 16 - encoder;

[0091] 17 - modulator.

[0092] The device comprises a series-connected antenna 1, a mixer 2, a high-frequency amplifier 3, a first mixer 4.1, a first stop filter 7.1, a first IF amplifier 8.1, a demodulator 9 and a VU 13, the first output of which is the output of the device. The second output of the demodulator 9 is connected through a decoder 10 to the second input of the VU 13. The second output of the VU 13 is connected through a series-connected encoder 16, modulator 17, the second IF amplifier 8.2, the third mixer 4.3 and the third stop filter 7.3 to the first input of the transmitter 6, the output of which is connected to the input of the antenna 1, the input-output of which is the input-output of the device. The third input of the VU 13 is the input of the device.

[0093] The third output of the VU 13 is connected to the input of the control device 15, the first output of which is connected to the second input of the modulator 17. The fourth output of the VU 13 is connected to the second input of the demodulator 9.

[0094] The output of the first IF amplifier 8.1 is connected to the input of the synchronization unit 11 and the first input of the second mixer 4.2, the output of which is connected to the fourth input of the VU 13 via the series-connected second PF 7.2 and the IMPS unit 14. The output of the synchronization unit 11 is connected to the third input of the demodulator 9 via the analog-to-digital converter 12. The second output of the control device 15 is connected to the second input of the transmitter 6. The third output of the control device 15 is connected to the input of the second frequency synthesizer 5.2, the output of which is connected to the second input of the second mixer 4.2. In this case, the output of the first frequency synthesizer 5.1 is connected to the second input of the first mixer 4.1. The output of the third frequency synthesizer 5.3 is connected to the second input of the third mixer 4.3.

[0095] The device operates as follows.

[0096] The description is given for the case of sequential processing of input signals.

[0097] The additive mixture of signal and interference from antenna 1 after filtering in SPF 2 and amplification in UHF 3 is fed to the first mixer 4.1, where the signal frequency is lowered (increased) to the intermediate frequency value by multiplying it by the signal coming from the output of the first frequency synthesizer 5.1.

[0098] The result of the conversion of the signal and interference mixture is then filtered in the first bandpass filter 7.1, the frequency band of which is matched to the signal band, amplified in the first IF amplifier 8.1 and fed to the first input of the demodulator 9, in which the signal is demodulated in accordance with the demodulation method used (the description of the method is given on pages 5÷6 of the description).

[0099] The structural diagram of the device, which can perform the functions of the demodulator 9, is shown in Fig. 3, where it is indicated:

[0100] 9.1.1÷9.1.n - from the first to the n-th multiplication blocks;

[0101] 9.2.1÷9.2.n - from the first to the n-th low-pass filters (LPF);

[0102] 9.3.1÷9.3.n - from the first to the n-th subtraction device (SD);

[0103] 9.4.1÷9.4.n - from the first to the nth analog-to-digital converters (ADC);

[0104] 9.5.1÷9.5.n - from the first to the n-th bandpass filters;

[0105] 9.6 - computing device (CD);

[0106] 9.7 - reference voltage block (RVB).

[0107] The demodulator contains n identical parallel lines, each of which consists of a corresponding, series-connected multiplication block 9.1, low-pass filter 9.2, subtraction device 9.3 and ADC 9.4, with a bandpass filter 9.5 connected between the output of the multiplication block 9.1 and the second input of the subtraction device 9.3.

[0108] The first n inputs of the 9.1.1÷9.1.n multiplier blocks are combined and are the first input of demodulator 9.

[0109] The outputs of the n ADCs 9.4.1÷9.4.n are connected to the corresponding first through n-th inputs of the computing device 9.6, the first and second outputs of which are the corresponding first and second outputs of the demodulator 9. The outputs of the first through n-th OpN blocks 9.7 are connected to the second inputs of the n multiplier blocks 9.1.1÷9.1.n, respectively. The first and second inputs of the OpN block 9.7 are the second and third inputs of the demodulator 9, respectively.

[0110] The demodulator works as follows.

[0111] The received additive mixture of signal and interference is fed to the first inputs of the multiplication blocks 9.1.1÷9.1.n, to the second inputs of which the corresponding reference signals are fed, for example, for the case of using single-frequency signals

[0112] U оп1 =sin(x1), U оп2 =cos(x1);

[0113] ….

[0114] U оп(n-1) =sin(x m ), U опn =cos(x m ).

[0115] Here m=n / 2.

[0116] The result of multiplying the signal and interference by the reference signals is split into two equal components. The first component is filtered by low-pass filters 9.2.1÷9.2.n, whose bands are matched to the signal band. Simultaneously, the second component is filtered by band-pass filters 9.5.1÷9.5.n, whose passbands are selected such that the upper frequency of band-pass filters 9.5.1÷9.5.n corresponds to the upper frequency of the signal, while the lower frequency of the band-pass filter is set as close to zero as possible.

[0117] The signals passing through low-pass filters 9.2.1÷9.2.n and band-pass filters 9.5.1÷9.5.n are subtracted from each other, respectively. That is, the signal of the first band-pass filter 9.5.1 is subtracted from the signal of the first low-pass filter 9.2.1, the signal of the second band-pass filter 9.5.2 is subtracted from the signal of the second low-pass filter 9.2.2, and so on.

[0118] The received signals are converted into digital form in ADC 9.4.1÷9.4.n. These digital signals are fed to computing device 9.6.

[0119] In computing device 9.6, using the values ​​corresponding to the sine and cosine components of one frequency, values ​​proportional to the value of the sum of the powers of harmonic signals and interference are calculated by summing their squares.

[0120] Reference signals are generated in the OpN block 9.7. The start of reference signal generation is determined by the signals fed in digital form from the output of the synchronization block 11 through the ADC 12 to the third input of the demodulator 9, which is the second input of the OpN block 9.7. Reference signals are generated using the values ​​of the signal numbers that are fed to the second input of the demodulator 9, which is the first input of the OpN block 9.7.

[0121] The obtained values ​​are considered an estimate of the power of the signals forming the INS. The INS is considered to have received the signal with the maximum power.

[0122] The number of the I / C and the corresponding binary sequence are determined, which is fed to the input of the decoder 10, where the information is decoded in accordance with the encoding method used, and then fed to the second input of the VU 13.

[0123] At the stage of establishing communication, and in the case of using harmonic frequency tuning, synchronization is performed at each change in the values ​​of the operating frequencies.

[0124] The synchronization unit 11 can be implemented, for example, in the form of a device, the structural diagram of which is shown in Fig. 4, where it is indicated:

[0125] 11.1 - phase discriminator (PD);

[0126] 11.2 - integrator;

[0127] 11.3 - voltage converter;

[0128] 11.4 - clock pulse generator (CPG).

[0129] The synchronization unit 11 contains a series-connected phase discriminator 11.1, an integrator 11.2, a voltage converter 11.3 and a voltage transducer 11.4, the first output of which is the output of the synchronization device 11, the second output of the voltage transducer 11.4 is connected to the second input of the phase discriminator 11.1, the input of which is the input of the synchronization unit 11.

[0130] Synchronization unit 11 works as follows.

[0131] In the phase tracking mode, the signal and interference mixture from the output of the first IF amplifier 8.1 (Fig. 2) is fed to the input of the phase discriminator 11.1, the second input of which receives signals from the GTI 11.4. The phase discriminator 11.1 generates a voltage (error voltage), the sign and amplitude of which are proportional to the sign and magnitude of the phase mismatch (time) between the clock pulses of the GTI 11.4 and the received symbols. A symbol, in this case, is a signal of a predetermined duration with fully known parameters, except for its arrival time (phase).

[0132] The voltage from the output of phase discriminator 11.1 is summed in integrator 11.2 and used to generate the control voltage in voltage converter 11.3 so as to minimize the phase misalignment. The voltage from the output of voltage converter 11.3 is fed to GTI 11.4, where the corresponding pulses are generated. In this case, voltage converter 11.3 converts the voltage, which varies within the range of U1 to U2, into a voltage, which varies accordingly within the range of U3 to U4 according to a specific functional relationship. The signal from the output of synchronization unit 11 is fed to the input of ADC 12, where it is converted to digital form and then fed to the third input of demodulator 9.

[0133] To ensure that the signal-to-noise ratio (SNR) values ​​are calculated, the following is performed.

[0134] Depending on the value of the central frequency of the signal, which is included in the set of signals that form any ICS, a code signal is generated in the VU 13, which is fed to the input of the control device 15. In accordance with this signal, a control signal is generated in the control device 15, which is fed from its third output to the input of the second FC 5.2, where the corresponding reference signal is generated.

[0135] The signal and interference mixture is multiplied by the reference signal in the second mixer 4.2. As a result, the difference (sum) frequency of the analyzed signal and the reference signal becomes equal to the center frequency of the second bandpass filter 7.2. The resulting signal is filtered in the second PF 7.2 and fed to the input of the IMPS block 14.

[0136] In the IMPS block 14, the mixture of signal and interference is processed using a method and device for isolating signals in the presence of interference, the description of which is given in patent RU No. 2675386H04B 1 / 10.

[0137] The structural diagram of the IMPS block 14 is shown in Fig. 5, where it is indicated:

[0138] 14.1 - splitter;

[0139] 14.2 - multiplication block;

[0140] 14.3 - bandpass filter;

[0141] 14.4.1÷14.4.2 - first and second analog-to-digital converters (ADC);

[0142] 14.5 - low-pass filter (LPF);

[0143] 14.6 - computing device (CD).

[0144] The IMPS block 14 contains a series-connected splitter 14.1, a multiplier block 14.2, a bandpass filter 14.3, the first ADC 14.4.1, a CU 14.6, the output of which is the output of the IMPS block 14. The second output of the splitter 14.1 is connected to the second input of the multiplier block 14.2, the output of which is connected through series-connected LPF 14.5 and the second ADC 14.4.2 to the second input of the computing device 14.6. The input of the splitter 14.1 is the input of the IMPS block 14.

[0145] The IMPS 14 block operates as follows.

[0146] The received additive mixture of signal and interference from the output of the first IF amplifier 8.1 (Fig. 2) is fed to the input of the IMPS block 14.

[0147] The mixture of signal and interference is split in splitter 14.1 into two identical components, which are fed to the first and second inputs of multiplication block 14.2, where they are multiplied by each other (squared).

[0148] The received signal is filtered using low-pass filter 14.5, the bandwidth of which is matched to the signal bandwidth. Simultaneously, the received signal is filtered using band-pass filter 14.3, the passband of which is selected such that the upper frequency of band-pass filter 14.3 corresponds to the upper frequency of the signal, and its lower frequency is selected as low as possible.

[0149] Form in digital form, by converting in the corresponding first 14.4.1 and second 14.4.2 ADC, samples of signals that have passed through the bandpass filter 14.3 and the low-pass filter 14.5.

[0150] These values ​​are subtracted from each other in VU 14.6. The resulting values ​​are summed.

[0151] The calculated values ​​of the interference power and the sum of the interference and signal from the output of the IMPS unit 14 are fed to the fourth input of the VU 13.

[0152] In VU 13, the sum of the values ​​of the signal power and the proportional power of the combination components of the signal and interference, the signal power and the interference power (2), calculated in the IMPS block 14, is subtracted from the sum of the values ​​of the signal power and the proportional power of the combination components of the reference signal and interference (1), calculated in the demodulator 9, an estimate of the interference power (P) is obtained. по ) (3).

[0153] Divide the value calculated using expression (1) by the value calculated using expression (3). The resulting value is considered as an estimate of the SNR value at the reception point of the transmitted messages.

[0154] The following operations are carried out in VU 13.

[0155] If information intended for a given station is received, it is fed to the first output of VU 13, which is the output of the device.

[0156] Calculates SNR values ​​when receiving messages and includes this information in service messages.

[0157] If a decision is made that the information was not received, a corresponding code signal is generated in VU 13. Information symbols are selected from among unused InSs, using which additional channels are formed. This information is included in the service message.

[0158] The information to be transmitted is divided into K streams, the volume of which is proportional to the data transfer rate in the corresponding channels. The duration of the ISS is increased so that the signal energy reaches the required level.

[0159] During the link establishment phase, the minimum required signal power is determined for each link, for example, by establishing a link using the maximum signal power value and then exchanging messages with the signal power reduced by a specified amount. During this process, the power level that ensures the specified message reception quality is determined in VU 13 using the calculated SNR value. When transmitting messages, the radiated power value is selected from the maximum value used for exchanging information with the selected stations.

[0160] These power values ​​in the form of corresponding code signals are fed from the third output of the VU 13 to the input of the control device 15, in which the corresponding control signal is generated and fed to the second input of the transmitter 6, where the gain of the power amplifier is set in accordance with this signal.

[0161] The control device 15 can be implemented in the form of a computing device, which can be implemented, for example, in the form of a single microprocessor device with the appropriate software, for example, a TMS320VC5416 series processor from Texas Instruments, or in the form of a programmable logic integrated circuit (FPGA) with the appropriate software, for example, an XCV400 FPGA from Xilinx.

[0162] Messages generated in VU 13 are fed to the input of encoder 16, where the information is encoded in accordance with the encoding method used.

[0163] Information from encoder 16 is fed to the input of modulator 17.

[0164] The modulator 17 can be implemented, for example, in the form of a device, the structural diagram of which is shown in Fig. 6, where it is indicated:

[0165] 17.1 - computing device (CD);

[0166] 17.2 - digital-to-analog converter (DAC);

[0167] 17.3 - bandpass filter.

[0168] Modulator 17 comprises a series-connected computing unit 17.1, a digital-to-analog converter 17.2, and a bandpass filter 17.3, the output of which is the output of the device. The input of the VU 17.1 is the input of the device.

[0169] Modulator 17 works as follows.

[0170] In computing unit 17.1, in accordance with the binary sequence received at its input and the number of modulation positions used, signal envelopes are formed in digital form, which form the corresponding ICS. The signal envelopes from VU 17.1 are fed to the input of DAC 17.2, where they are converted to analog form and fed to the input of bandpass filter 17.3. The signal is filtered by bandpass filter 17.3 and fed to the modulator output. The bandwidth of bandpass filter 17.3 is matched to the signal bandwidth.

[0171] The signal generated in modulator 17 is fed to the input of the second IF amplifier 8.2 (Fig. 2). The amplified signal is fed to the first input of the third mixer 4.3, where the frequency of the generated signal is lowered (increased) to the required frequency value by multiplying the signal by the signal of the third midrange 5.3. The signal is then filtered in the third bandpass filter 7.3, the frequency band of which is matched to the signal band.

[0172] The signal is then fed to the first input of transmitter 6, where it is amplified and filtered accordingly. The generated signal is emitted into space through antenna 1.

[0173] The computing devices 9.6, 13.1 4.6 and 17.1 can be implemented, for example, in the form of a single microprocessor device with the appropriate software, for example, the TMS320VC5416 series processor from Texas Instruments, or in the form of a programmable logic integrated circuit (FPGA) with the appropriate software, for example, the XCV400 FPGA from Xilinx.

[0174] ADC 9.4.1 - 9.4.n, 12.1 4.4.1, 14.4.2 can be implemented, for example, on the AD7495BR microcircuit from Analog Devices.

[0175] DAC 17.2 can be implemented, for example, on the AD5443YRM chip from Analog Devices.

[0176] Thus, the claimed method can be implemented by the described device.

Claims

A method for packet transmission of messages in a communication network using additional channels, which consists in the fact that in communication stations, a continuous analysis of the state of all channels allocated for communication and the storage of information about this, the allocation for transmission, reception, analysis, joint processing of received signals of several frequency channels, the formation of new communication plans, the transmission of this information to the corresponding subscribers of the system, its storage until the degradation of the parameters of at least one of the operating radio channels, and the transition to a new communication plan in the future, characterized in that the stations operate in a "multipoint-to-multipoint" network, the stations use modulation with a frequency shift and processing that ensures the quasi-orthogonality of any pair of harmonics used and, accordingly, ensures frequency division of the channels, while the difference in the frequency values ​​of any pair of adjacent harmonics exceeds the established threshold value; information symbols are formed as a sequence of different signals, the signals consist of the sum of several harmonics, the signals used to form different information symbols differ in the values ​​of the frequencies of the harmonics that form the signals, the number of information symbols used for transmission over one channel is determined by the number of modulation positions; the numbers of information symbols are determined in advance; to form various communication channels, various information symbols are used; the total number of channels that can be used exceeds by a set number of times the maximum number of communication lines through which simultaneous information exchange can be carried out in the communication network; at the stage of establishing communication, synchronization is carried out, the minimum required value of signal power is set for each communication line; when establishing communication with several radio stations, the value of the output signal power is set equal to the maximum value, which is selected from the values ​​of the signal powers simultaneously transmitted by the station; stations exchange service and user information; for the first cycles of receiving and transmitting messages, they use information symbols, the numbers of which are determined in advance; their number and the number of channels are determined using a priori information about the possible values ​​of interference parameters; at each reception of messages, the state of the communication channels is analyzed by measuring the values ​​of the power of the sum of the interference and the signal and interference in the corresponding frequency bands, calculating the values ​​of the signal-to-noise ratio (SNR) at the point of reception of messages, and comparing the obtained SNR values ​​with the established threshold value; if a decision is made that the information is not received, the station transmits a corresponding code signal to another station; in the transmitting station, upon receiving this code signal, the number of channels and, accordingly, the number of information symbols used to transmit information are increased by the established value; in the next cycle of transmitting and receiving messages, the information not received by the other party and new numbers of the information symbols used - additional symbols - are retransmitted; if the transmitting station has not received information about the reception of information by another station, transmission is carried out using additional information symbols; the process continues until the transmitting station receives a message about the reception of the transmitted information by another station, or until all additional information symbols that can be allocated at the station at a given moment in time are exhausted.

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