Digital radio communication system using noise-like signals with very long bases

Abstract

FIELD: radio communications.SUBSTANCE: invention can be used in the construction of adaptive radio communication systems and complexes with code division of subscribers for operation under conditions of interference. A block of matched filters is additionally introduced into the digital radio communication system, which performs digital processing of noise-like signals with very large bases in real time, the output of which is connected to a decoder, and the input is connected to an analogue-to-digital converter additionally introduced into the high-frequency path of the radio receiving device, the input of which is connected to the output of a power amplifier. In addition, a digital-to-analogue converter is additionally introduced into the high-frequency path of the radio transmitting device, the output of which is connected to the input of the power amplifier, and the input is connected to the output of the modulator of the useful information receiving and transmitting unit.EFFECT: increasing the throughput and noise immunity of a digital radio communication system due to digital processing of noise-like signals with extremely large bases in a block of matched filters in real time.1 cl, 1 dwg

Description

[0001] The invention relates to the field of radio communications and can be used in the construction of adaptive systems and complexes of radio communications with code division of subscribers for operation under conditions of interference that exceed the power level of the useful signal, and multipath propagation of radio waves.

[0002] Broadband communication systems with noise-like signals (BNS) have a number of advantages over narrowband communication systems: high noise immunity, the ability to resist detection, the possibility of code division of subscribers, resistance to multipath propagation, good electromagnetic compatibility (Varakin, L.E. Communication systems with noise-like signals / L.E. Varakin. - Moscow: Radio and communication, 1985. - 384 p.).

[0003] In a SPS communication system, the receiving section must include either a correlator or a matched filter. Practically, a software-defined radio system using these devices can only be implemented digitally, which is why the receiving device is built using digital signal processing. In this case, the throughput of a digital radio system will directly depend on the speed of the computing unit, since a certain number of mathematical operations with signal samples must be performed within a fixed time. This is a challenge for processing high-frequency (HF) signals with long baselines.

[0004] Reception of a digital radio communication system by a matched filter is accompanied by interference suppression by a factor of 2*B, where B is the signal base (L.E. Varakin. Communication systems with noise-like signals. - Moscow: Radio and communication, 1985. - 384 p.), therefore, the noise immunity of a digital radio communication system depends on the size of the signal base. Thus, the noise immunity of a digital radio communication system depends on the speed of the computing part.

[0005] A digital communication system with noise-like signals is known (Patent No. RU 14710 U1 Russian Federation, IPC H04K 1 / 00 ​​(2000.01), Digital communication system with noise-like signals: No. 2000105161 / 20: declared 03.03.2000: published 10.08.2000 / Voronin E.I., Belov L.A.; applicant and patent holder Moscow Power Engineering Institute. - 6 p.).A digital communication system with noise-like signals, containing an encoder, one input of which is the input of the system, and a pseudo-random sequence generator, a series-connected communication channel, a demodulator, a matched filter, and a decision device, connected to its other two inputs, characterized in that it is equipped with a modulo-two adder, an additional pseudo-random sequence generator, connected to one input of the modulo-two adder, the other input of which is connected to the output of the encoder, and the output is connected to the input of the communication channel, and a voltage modulus calculation unit, connected in series between the output of the matched filter and the input of the decision device.

[0006] A digital communication system with phase-frequency-shift keyed (PM-FM) signal transmission is known (Varakin, L.E. Communication systems with noise-like signals / L.E. Varakin. - Moscow: Radio i svyaz, 1985. - 384 p, Fig. 1.12). The transmitter circuit and the receiver circuit are a combination of transmitters and receivers (Varakin, L.E. Communication systems with noise-like signals / L.E. Varakin. - Moscow: Radio i svyaz, 1985. - 384 p, Fig. 1.7, 1.11). To further improve noise immunity, correcting codes are used, which are formed in the transmitter using an encoder and decoded in the receiver using a decoder. In the receiver, optimal filtering is performed by a correlator. This device is the closest in technical essence to the claimed invention and was chosen as the closest analogue (prototype).

[0007] A common drawback of both of the above systems is that matched filtering is implemented in analog form, which does not allow for sufficient flexibility in the digital communication system. In particular, it is impossible to increase the signal base sufficiently to ensure high throughput and noise immunity. Analog signal processing also does not allow for the use of various types of signal processing systems.

[0008] The main task that the proposed invention is aimed at solving is to increase the efficiency of digital signal processing in a matched filter block, which makes it possible to create broadband communication systems with broadband signals with extremely large bases.

[0009] The implementation of the set task allows us to achieve the following overall technical result:

[0010] - increasing the throughput and noise immunity of a digital radio communication system through digital processing of noise-like signals with extremely large bases in a matched filter block in real time.

[0011] A digital radio communication system using noise-like signals with extremely long baselines comprises a terminal and a two-way communication device for controlling the digital radio communication system connected thereto; a useful information receiving and transmitting unit consisting of a decoder, an information processor connected in series with a two-way communication device for controlling the digital radio communication system, an encoder and a modulator; a high-frequency path of the radio receiving device consisting of a receiving magnetic antenna and a power amplifier connected in series; a high-frequency path of the radio transmitting device consisting of a power amplifier and a transmitting broadband whip antenna connected in series.

[0012] The fundamental difference from the prototype is that a matched filter block is additionally introduced into the useful information receiving and transmitting unit of the digital radio communication system using noise-like signals with extra-large bases, which performs digital processing of noise-like signals with extra-large bases in real time, the output of which is connected to the decoder, and the input is connected to an analog-to-digital converter additionally introduced into the high-frequency path of the radio receiving device, the input of which is connected to the output of the power amplifier, in addition, a digital-to-analog converter is additionally introduced into the high-frequency path of the radio transmitting device, the output of which is connected to the input of the power amplifier, and the input is connected to the output of the modulator of the useful information receiving and transmitting unit.

[0013] The functional diagram of the digital radio communication system is shown in Fig. 1:

[0014] Digital radio communication system using noise-like signals with extra-large bases consisting of:

[0015] 1. Terminal

[0016] 2. Digital radio communication system control device

[0017] 3. Useful information receiving and transmitting unit

[0018] 3.1. Decoder

[0019] 3.2. Matched Filter Block

[0020] 3.3. Information Processor

[0021] 3.4. Encoder

[0022] 3.5. Modulator

[0023] 4. High-frequency (HF) path of the radio receiver

[0024] 4.1. Receiving magnetic antenna

[0025] 4.2. Power amplifier

[0026] 4.3. Analog-to-Digital Converter (ADC)

[0027] 5. High-frequency (HF) path of the radio transmitting device

[0028] 5.1 Digital-to-analog converter (DAC)

[0029] 5.2. Power amplifier

[0030] 5.3. Transmitting broadband whip antenna

[0031] The digital radio communication system comprises a digital radio communication system control device 2, which is connected on one side by two-way communication with the terminal 1, and on the other side by two-way communication with the information processor 3.3 of the useful information receiving and transmitting unit 3. The information processor 3.3 of the useful information receiving and transmitting unit 3 processes the useful information coming from the decoder 3.1 of the useful information receiving and transmitting unit 3 and sends it to the digital radio communication system control device 2, and the information processor 3.3 of the useful information receiving and transmitting unit 3 processes the data coming from the digital radio communication system control device 2 and sends them to the encoder 3.4 of the useful information receiving and transmitting unit 3. The encoder 3.4 of the useful information receiving and transmitting unit 3 encodes the useful information and sends it to the modulator 3.5 block for receiving and transmitting useful information 3, which forms the signal-to-noise ratio, then the digital readings are sent to the digital-to-analog converter 5.1 of the RF path of the radio transmitting device 5, where they are converted into a radio signal. The radio signal is amplified by the power amplifier 5.2 of the RF path of the radio transmitting device 5 and is emitted into space by the transmitting broadband whip antenna 5.3 of the RF path of the radio transmitting device 5. The input radio signal is fed to the receiving magnetic antenna 4.1 of the RF path of the radio receiving device 4, then amplified by the power amplifier 4.2 of the RF path of the radio receiving device 4 and digitized by the analog-to-digital converter 4.3 of the RF path of the radio receiving device 4. After this, the data are sent to the matched filter unit 3.2 of the useful information reception and transmission unit 3. The matched filter unit 3.2 of the useful information reception and transmission unit 3 is tuned to the alphabet of the broadband signal system of the useful information and, if a signal is present, transmits it to the decoder 3.1 block for receiving and transmitting useful information 3, then to the information processor 3.3 block for receiving and transmitting useful information 3.

[0032] Terminal 1, digital radio communication system control device 2 and information processor 3.3 perform the functions of an information receiver and source, as well as device synchronization.

[0033] Encoder 3.4 and decoder 3.1 implement noise-resistant coding and decoding functions.

[0034] Modulator 3.5 matches binary code and SPS from the alphabet.

[0035] The RF path of the radio receiving device 4 receives the radio signal and converts it into a digital code.

[0036] The RF path of the radio transmitting device 5 converts the digital code into an analog signal and emits a radio signal into space.

[0037] The digital radio communication system using noise-like signals with extra-long baselines operates as follows.

[0038] The input radio signal is received by the receiving magnetic antenna 4.1 of the RF path of the radio receiving device 4, then amplified by the power amplifier 4.2, and then converted into a sequence of digital samples using the ADC 4.3. These samples are fed to the matched filter unit 3.2 of the useful information transmission and reception unit 3. The operation of the matched filter unit 3.2 is simulated using a computer program (Computer program registration certificate No. 2025686194 Russian Federation: Program for digital signal processing research: No. 2025684523: declared 09 / 17 / 2025: published 09 / 30 / 2025 / Gavrilov A.A.)

[0039] Matched Filter Block 3.2 performs digital signal processing as follows:

[0040] The width of the spectrum of the SPS is selected based on the ratio

[0041]

[0042] where ΔF is the width of the spectrum of the broadband signal, Hz; n is an integer, n > 2; t s - duration of the SHPS, s.

[0043] After receiving an incoming radio signal, its spectrum is calculated using a fast Fourier transform (FFT). Bandpass filtering is then performed by cutting off frequency components outside the NPS band. The NPS spectrum is then rarefied with a reduction factor k using an 8th-order Chebyshev filter with an infinite impulse response. For signal demodulation, the entire NPS alphabet is first subjected to a procedure similar to the one described above and stored in the memory cells of the matched filter block. Next, the reduced FFT of the received radio signal is multiplied element-by-element with each of the reduced FFTs of the NPS alphabet stored in memory. Then, the inverse FFT (IFFT) of the resulting vectors is calculated. The correspondence of a received symbol to the NPS alphabet is determined by the maximum of the corresponding IFFT.

[0044] The results of simulation modeling using the developed computer program showed that the duration of digital signal processing can be reduced by thousands and tens of thousands of times thanks to the developed block of matched filters, depending on the value of the reduction coefficient k, which makes it possible to perform digital processing of noise-like signals with extremely large bases in real time.

[0045] The received symbols from matched filter block 3.2 of payload transmit / receive block 3 are accumulated in decoder 3.1, which performs noise-immune decoding using the Reed-Solomon code. The digital information is then sent to data processor 3.3, then to digital radio system control unit 2, and then to terminal 1.

[0046] The information to be transmitted is fed to terminal 1, then to digital radio communication system control unit 2, then to data processor 3.3 of payload transmission / reception unit 3, after which it is accumulated in encoder 3.4 for noise-resistant Reed-Solomon coding. The binary information is then fed in blocks to modulator 3.5, where the binary value is compared with digital samples of the corresponding radio signal from the alphabet. The digital samples are then converted into signal voltage by DAC 5.1 of the RF path of radio transmitting device 5. The signal is amplified by power amplifier 5.2 and radiated into space via transmitting broadband whip antenna 5.3.

[0047] Thus, the declared “Digital radio communication system using noise-like signals with extra-large bases” makes it possible to exchange digital information with high noise immunity and throughput, using a noise-like signal with extra-large bases.

[0048] The claimed method is industrially applicable, since widely used components and products of the radio engineering industry and computing technology are used for its implementation.

Claims

A digital radio communication system using noise-like signals with very long bases, comprising a terminal and a digital radio communication system control device connected to it by two-way communication; a useful information receiving and transmitting unit consisting of a decoder, an information processor connected in series by two-way communication with the digital radio communication system control device, an encoder and a modulator; a high-frequency path of the radio receiving device, consisting of a receiving magnetic antenna and a power amplifier connected in series;a high-frequency path of a radio transmitting device consisting of a series-connected power amplifier and a transmitting broadband whip antenna, characterized in that a matched filter unit is additionally introduced into the unit for receiving and transmitting useful information of the digital radio communication system using noise-like signals with extremely large bases, which unit performs digital processing of noise-like signals with extremely large bases in real time, the output of which is connected to a decoder, and the input of which is connected to an analog-to-digital converter additionally introduced into the high-frequency path of the radio receiving device, the input of which is connected to the output of the power amplifier; in addition, a digital-to-analog converter is additionally introduced into the high-frequency path of the radio transmitting device, the output of which is connected to the input of the power amplifier, and the input is connected to the output of the modulator of the unit for receiving and transmitting useful information.

Images