RU2343638C1 - Radio channel for signals with pseudorandom operational frequency readjustment - Google Patents

Abstract

FIELD: physics; radio.

SUBSTANCE: present invention pertains to radio engineering and can be used in radio systems, meant for setting up a radio communication channel for broadband signals with pseudorandom operational frequency readjustment. Device comprises transmitter and, at least, one receiver. The transmitter comprises source of information, pseudorandom sequence generator (PSG), K sources of modulated signal, K tuneable forced oscillations generators, K controlled broadband attenuators, a unit for controlling the broadband attenuators and a unit for holding and dividing the code of PSG into K commands. The receiver comprises broadband filter, tuneable band-pass filter, signal demodulator, pseudorandom sequence generator and delay circuit.

EFFECT: lower level of out-of-band emissions.

14 dwg

Description

The present invention relates to the field of radio communications and can be used in radio systems designed to organize a radio communication line in the mode of broadband signals 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 the book [1].

Known communication systems operating in the mode of jumps (jumps) in frequency, described in [2] and [3]. A drawback in the operation of these communication systems with frequency hopping is the interference with radio reception due to significant out-of-band emissions from the transmitters.

Closest to the technical nature of the proposed one is the radio line shown in Fig.1.7a, 1.7b p.24 in the book [1], adopted as a prototype.

The functional diagram of the prototype device is shown in figa, 1b.

On figa indicated:

1 - transmitter;

2 - source of information;

3.1 - modulator;

3.2 - frequency generator;

4.1 - transmitter mixer;

4.2 - transmitter frequency synthesizer;

5 - generator pseudo-random sequence (PSP) of the transmitter.

On figb designated:

6 - receiver;

7 - broadband filter;

8.1 - receiver mixer;

8.2 - band-pass filter;

8.3 - receiver frequency synthesizer;

9 - signal demodulator;

10 - receiver bandwidth generator.

It is advisable to enlarge the functional diagram of the prototype device as follows:

At the transmitting end, a modulator 3.1 and a transmitter frequency generator 3.2 can be represented as a single unit - a modulated signal source (IC) 3 ₁ , a transmitter mixer 4.1 and a transmitter frequency synthesizer 4.2 can be combined in one unit - a tunable forced oscillation generator (PGWC) 4 ₁ .

At the receiving end, a receiver mixer 8.1, a band-pass filter 8.2, and a frequency synthesizer for receiver 8.3 can be combined in one unit - a tunable band-pass filter (PF) 8.

In addition, the SRP signals in the transmitter SRP generator 5 and the receiver SRP generator 10 can be generated not in a parallel code, as in figa 1b, but in a serial code. And in this case, the connection of blocks 5 and 10 with the corresponding blocks 4.2 and 8.3 can be carried out by single wires.

An enlarged diagram of the prototype device is presented in figa, 2b.

On figa indicated:

1 - transmitter;

2 - source of information;

3 ₁ - modulated signal source (IC);

4 ₁ - tunable generator of forced oscillations (PGVK);

5 - transmitter PSP generator.

On figb designated:

6 - receiver;

7 - broadband filter;

8 - tunable band-pass filter (PF);

9 - signal demodulator;

10 - receiver bandwidth generator.

Radio line - prototype contains transmitting and receiving parts.

The transmitting part (see Fig. 2a) is a transmitter 1 containing a series-connected information source 2, a modulated signal source (IC) 3 ₁ and a tunable forced oscillation generator (PGWC) 4 ₁ , to the control input of which the output of the transmitter PSP generator 5 is connected . In this case, the information source 2 is the input stage of the transmitter 1, and the output of the PGVK 4 ₁ is the output of the transmitter 1.

The receiving part (see fig.2b) contains at least one receiver 6, containing a serially connected broadband filter 7, tunable PF 8 and a signal demodulator 9, the output of which is the output of the receiver 6. In addition, it contains a generator of the receiver bandwidth 10, the output of which is connected to the control input of the tunable PF 8.

Consider the work of the prototype in the transmitting part.

In the transmitter 1, the input information from block 2 is converted in block 3 ₁ into a modulated radio frequency. Next, block 4 ₁ transfers the modulated radio frequency to the output radio frequency determined by the SRP signal from block 5, and emits it for a given period of time. In the next period of time, as in the previous one, the input information from block 2 goes to block 3, where it is converted to a modulated radio frequency, and block 4 ₁ transfers the modulated radio frequency to the output radio frequency determined by the SRP signal from block 5, and emits it during the second time span. The second output radio frequency is usually different from the first. Similarly, the operation of the transmitter 1 and in subsequent periods of time.

Consider the work of the prototype in the receiving part.

In the receiver 6, the received RF signals are filtered at the input by block 7, and then fed to block 8, in which the useful signal is selected and fed to the signal demodulator 9. The output signal of demodulator 9 is information that corresponds to the information supplied to the input stage of transmitter 1. Tuning PF 8 occurs by control signals from the generator of the SRP receiver 10.

It should be noted that the operation of the radio link is considered in synchronism mode, i.e. the generators of the SRP transmitter 5 and receiver 10 operate synchronously. Therefore, for this reason, radio signals in the corresponding time intervals are received by the receiver (or several receivers) due to synchronous frequency tuning. Synchronization of blocks 5 and 10 is carried out in advance by one of the known methods. The synchronization issue is considered in detail in chapter 6 of the book [1].

To facilitate understanding of the prototype, figure 3 shows the conditional diagram of the operation in the frequency hopping mode.

As can be seen from the example shown in figure 3, the transmitter signal is emitted sequentially at frequencies f ₃ , f ₁ , f ₂ , f ₃ , f ₂ , and the radiation time at each frequency position is equal to T ₀ (constancy of the time interval is optional) .

In other words, at the initial moment, at the output of the PGVC 4 _1, there is an output radio frequency f ₃ , which is radiated for a given first period of time T ₀ . In the next time interval (2T ₀ -T ₀ ), the transmission at the radio frequency f ₃ stops and is carried out at the output radio frequency f ₁ , which is different in nominal value from the previous one, as in the first time interval, in the second time interval, the radio frequency is modulated in accordance with the transmitted information in the transmitter. In the third period of time (3T ₀ -2T ₀ ), the process is repeated at the output frequency f ₂ , etc. The nominal carrier frequency is changed from one time interval to another according to a pseudo-random law sequentially at frequencies determined by the transmitter PSP generator 5. Radio signals are received at the corresponding time intervals by the receiver due to the synchronous frequency tuning of the PF 8 under the influence of the PSP generator of the receiver 10. In a particular case, the tunable PF 8 can be made in the form of a superheterodyne mixer, to one input of which a signal is supplied, to the other - voltage from the local oscillator (synthesizer), tunable by the clock frequency, and at the output, frequencies equal to the difference (sum) of the frequencies of the input signal and the local oscillator voltage are allocated, the filter is allocated to the intermediate frequency. Without violating the following statement, the word “filter” can, in particular, mean a coordinated optimal filter.

The spectrum of the signal emitted by the transmitter during frequency jumps, respectively, according to the above algorithm shown in Fig.3, is a spectrum of a rectangular radio pulse and has the form depicted in Fig.4 and Fig.5.

. На фиг.5 приведен спектр при значительных отстройках (в дальней зоне). В качестве отстройки принято x=f·T₀, где x - частота, нормированная к Т₀. Из графиков видно, что полоса, занимаемая сигналом по уровню минус 60 дБ, превышает полосу, занимаемую сигналом, в 300 раз, а по уровню минус 80 дБ - превышает полосу, занимаемую сигналом, в 3000 раз.In Fig. 4, the solid line shows the spectrum for small detunings (in the near zone), and the dashed curve shows the approximating curve

. Figure 5 shows the spectrum with significant offsets (in the far zone). As a detuning, x = f · T ₀ , where x is the frequency normalized to T ₀ . From the graphs it can be seen that the band occupied by the signal at a level of minus 60 dB exceeds the band occupied by the signal by 300 times, and at the level of minus 80 dB it exceeds the band occupied by the signal by 3000 times.

The disadvantage of the radio link prototype is that it creates significant interference due to out-of-band radiation of the transmitter, and the band occupied by these interference is ten times greater than the frequency band necessary for transmitting information. This phenomenon limits the use of communication systems with frequency hopping, as they create significant interference with other radio links, including radio links with frequency hopping. Therefore, the prototype device has significant out-of-band emissions and inefficiently uses the frequency range.

To eliminate this drawback in a radio link containing a transmitting and receiving parts, the transmitting part being a transmitter containing a serially connected information source and a first modulated signal source, as well as a pseudo-random sequence generator (PSP) of the transmitter and a first tunable generator of forced oscillations, the source being information is the input stage of the transmitter, and the output of the first tunable generator of forced oscillations is the output of the transmitter In the receiver, there is at least one receiver containing a receiver PSP generator and a broadband filter connected in series, the input of which is the receiver input, a tunable band-pass filter and a signal demodulator, the output of which is the receiver output, according to the invention, is inserted into the transmitter - (K-1) modulated signal sources, K controlled broadband attenuators, (K-1) tunable forced oscillation generators, control unit for broadband attenuators and delay unit and dividing the transmitter PSP code into “K” commands, while the inputs (K-1) of the modulated signal sources are connected to the input of the first modulated signal source, the outputs (K-1) of tuned forced oscillators are connected to the output of the first tuned forced oscillator, outputs To the sources of the modulated signal are connected to the high-frequency inputs To the corresponding controlled broadband attenuators, the outputs of which are connected to the information inputs To the corresponding tunable forced oscillators, the output of the transmitter PSP generator is connected to the input of the control unit of the broadband attenuators, the outputs of which are connected to the control inputs of the controlled broadband attenuators, respectively, in addition, the output of the transmitter PSP generator is connected to the input of the delay unit and the separation of the transmitter PSP code to “K” commands, the outputs of which are connected to the control inputs of the corresponding tunable generators of forced oscillations; introduced into the receiver is a delay circuit, the output of which is connected to the control input of the tunable band-pass filter, and the input is connected to the output of the receiver bandwidth generator.

On figa and 6b presents a functional diagram of the proposed radio link for signals with pseudo-random tuning of the operating frequency.

On figa indicated:

1 - transmitter;

2 - source of information;

3 ₁ ... 3 _K - sources of the modulated signal (IC);

4 ₁ ... 4 _K - tunable forced oscillation generators (PGVK);

5 - transmitter PSP generator;

11 ₁ ... 11 _K - controlled broadband attenuators (SHA);

12 - control unit for broadband attenuators (BUSH);

13 - block delay and separation of the code of the PSP transmitter on the "K" teams (BZRK).

On figb designated:

6 - receiver;

7 - broadband filter;

8 - tunable band-pass filter (PF);

9 - signal demodulator;

10 - receiver bandwidth generator;

14 is a delay circuit.

The proposed radio link for signals with frequency hopping contains transmitting and receiving parts.

The transmitting part (see figa) is a transmitter 1 containing an information source 2, which is the input stage of the transmitter 1, the output of which is connected to the inputs K of the sources of modulated signal (IC) 3 ₁ -3 _K , the outputs of which are connected to the high-frequency inputs of the corresponding By broadband controlled attenuators (SHA) ₁₁ January -11 _K, whose outputs are connected to data inputs of the corresponding K tunable forced vibration generators (PGVK) of 4 _{1 to} 4 _K, the outputs of which are combined in the transmitter output 1. also forehand snip generator 1 comprises a pseudorandom sequence (PRS) of the transmitter 5, whose output is connected to the input of the control unit broadband attenuators (BUSH) 12 to which outputs are connected to the control inputs to the respective control SHA January ₁₁ -11 _K. In addition, the output of the transmitter PSP generator 5 is connected to the input of the delay unit and the separation of the transmitter PSP code into “K” commands (BZRK) 13, the outputs of which are connected to the control inputs K of the corresponding PGVK 4 ₁ -4 _K.

The receiving part (see Fig.6b) contains at least one receiver 6 (may contain several receivers). The receiver 6 contains a series-connected broadband filter 7, the input of which is the input of the receiver 6, a tunable band-pass filter (PF) 8 and a signal demodulator 9, the output of which is the output of the receiver 6; in addition, it contains a receiver bandwidth generator 10, the output of which through a delay circuit 14 is connected to the control input of the tunable PF 8.

Consider the operation of the proposed radio link.

As mentioned above, the synchronization of the transmitter bandwidth generator 5 and the receiver bandwidth generator 10 is carried out in advance by one of the known methods. In other words, blocks 5 and 10 operate in synchronism, therefore, radio signals are received at appropriate intervals by a receiver (or several receivers) due to synchronous frequency tuning under control of blocks 5 and 10.

The input signal comes from the information source 2 to the inputs of the IC 3 ₁ -3 _K , the output carrier radio frequency of which is modulated according to the law of the input information. From the outputs of blocks 3 ₁ -3 _{K, the} modulated signals are simultaneously fed to the high-frequency inputs of the corresponding blocks 11 ₁ -11 _K , the attenuation coefficients of which are regulated by the corresponding control commands of block 12, which, in turn, operates in accordance with the SRP signals generated by block 5. From the outputs of blocks 11 ₁ -11 _{K, the} signals are fed to the information inputs of the corresponding PGVK 4 ₁ -4 _K , the output signals of which are emitted by the transmitter 1, and the frequency of each PGVK is set in accordance with the commands supplied to their control inputs from the corresponding outputs of block 13, which, in turn, operates in accordance with the PSP code supplied to its input from block 5. Thus, information is transmitted at different frequencies in accordance with the control signals generated by the transmitter PSP 5 generator but the start and end signal generating i-th (1 <i≤K) PGVK unit 4 _i is happening time interval of information transmission on a given frequency T _0, and begins earlier in time, (K-1) · T _0/2, monotonously increasing to the maximum value in time (K-1) T _0/2. After the end of the transmission at the maximum level, during the period of time T ₀ the transmission level monotonically decreases from the maximum value to the minimum (zero) during the time (K-1) · T _0/2 . Thus, each of PGVK 4 ₁ ... 4 _K works without frequency tuning during the time K · T ₀ , but only in the interval T _{0 it} works with maximum power. Blocks 5, 12 and 13 work in such a way that at any moment of time only one of the PGVK 4 ₁ -4 _K works with the maximum power level.

, по этой причине для обеспечения синхронизации генератор ПСП приемника 10 соединен с управляющим входом перестраиваемого ПФ 8 через схему задержки 14.Note that the carrier frequency is changed from one time interval to another according to a pseudo-random law sequentially, these frequencies are determined by the transmitter PSP generator 5, and the maximum voltage at the outputs of blocks 11 ₁ -11 _K appears after the start of their operation with a time delay

, for this reason, to ensure synchronization, the receiver bandwidth of the receiver 10 is connected to the control input of the tunable PF 8 through the delay circuit 14.

Consider the work at the receiving end. Received by the receiver 6, the radio frequency signals are filtered at the input by a broadband filter 7, and then fed to the tunable PF 8, in which the useful signal is selected and fed to the signal demodulator 9, the output of which is the output signal of the receiver 6. The output signal of the demodulator 9 is information that matches with the information supplied to the input stage of the transmitter 1. The tuning of the PF 8 is carried out by commands from the generator of the PSP of the receiver 10, supplied through the delay circuit 14.

The control unit for broadband attenuators (BUSH) 12 can be implemented according to the functional diagram shown in Fig.7, where the following notation is introduced:

12.1 - counter on K;

12.2 - demultiplexer;

12.3 ₁ ... 12.3 _K - synchronous single vibrators;

12.4 ₁ ... 12.4 _K - counters on N;

12.5 ₁ ... 12.5 _K - read-only memory (ROM);

12.6 ₁ ... 12.6 _K - digital- _to -analog converters (DAC);

12.7 - clock generator.

The input of BUSH 12 is the information input of the demultiplexer 12.2 connected to the counter input of the counter to K 12.1, the outputs of which are connected to the corresponding address inputs of the demultiplexer 12.2, the outputs of which are connected to the start inputs K of the corresponding synchronous single-vibrators 12.3 ₁ -12.3 _K , the outputs of which are connected to to the count input of counters corresponding to N 12.4 ₁ -12.4 _K outputs which are connected to busbars group address inputs of ROM groups to the corresponding ₁ 12.5 -12.5 _K outputs which are connected to groups of tires groups It moves the corresponding DAC 12.6 -12.6 _{K 1,} the outputs of which are the respective outputs of the clock generator 12. BUSH output 12.7 is coupled to clock inputs to the synchronous monostable multivibrators 12.3 ₁ -12.3 _K and K counters on N 12.4 ₁ -12.4 _K.

Block 12 operates as follows.

The signal from the output of the generator of the PSP transmitter 5 is supplied simultaneously to the counter input of the counter to K 12.1 and to the information input of the demultiplexer 12.2. The output code of the counter at K 12.1 is supplied to the address inputs of the demultiplexer 12.2. After each new signal received at the input of block 12, the state of the counter 12.1 changes and its output code changes accordingly. Block 12.2 transmits the information received at its information input to one of its K outputs, for example, to the i-th (1 <i≤K) output. The signal from the i-th output of block 12.2 in accordance with the code installed on its address inputs is fed to the start input of the corresponding synchronous single-shot 12.3 _i .

Thus, each i-th output signal of block 12.2 triggers a single-vibrator 12.3 _i corresponding to it, which generates at its output a pulse with a length equal to the length of the interval K · T ₀ supplied to the counting input of the resolution of the counting of the corresponding counter to N 12.4 _i . During this time, the counter at N 12.4 _i counts the pulses arriving at its counting input, and the code at its outputs sequentially changes from 0 to (N-1). Further, from the counter output to N 12.4 _{i, the} code goes to the address bus of the corresponding ROM 12.5 _i , in which data are written in advance, the value of which ensures a monotonic increase and a monotonic decrease in the transmission coefficient, for example, in accordance with formula (1) below. Data information from the ROM 12.5 _i bus is fed to the information input of the corresponding DAC 12.6 _i , where it is converted into a continuous signal supplied to the i-th output of block 12 to control the corresponding broadband attenuator.

Examples of the implementation of the counter on K and the counter on N are given in [4] on page 354, Fig. 20.14.

An example of the implementation of the demultiplexer (selector) 12.2 is given in [4] on page 328, Fig. 19.8.

An example of the implementation of a synchronous single vibrator 12.3 is given in [4] on page 361, Fig. 30.31.

On Fig presents a functional block diagram of the delay and separation of the code of the SRP transmitter on the "K" teams (BZRK) 13, where it is indicated:

13.1 - counter on K,

13.2 - demultiplexer.

BZRK 13 contains a counter on K 13.1, the counting input of which, which is the input of the BZRK 13, is connected to the information input of the demultiplexer 13.2. In this case, the outputs of the counter 13.1 are connected to the corresponding address inputs of the demultiplexer 13.2, the outputs of which are the corresponding outputs of the BZRK 13.

Block 13 operates as follows.

The signal from the output of the generator of the PSP transmitter 5 is supplied simultaneously to the counter input of the counter to K 13.1 and to the information input of the demultiplexer 13.2. The output code of the counter on K 13.1 is supplied to the address inputs of the demultiplexer 13.2. After each new signal received at the input of block 13, the state of the counter 13.1 changes, and accordingly, its output code changes. Demultiplexer 13.2 transmits the information received at its information input to one of its K outputs in accordance with the code installed on its address inputs. Thus, in block 13, separation (distribution) of the output signal of block 5 into K output signals is performed.

An example of the implementation of the counter on K 13.1, performed on meters with a preset, is given in [4] on page 354, Fig. 20.14.

An example of the implementation of the demultiplexer (selector) 13.2 is given in [4] on page 328, Fig. 19.8.

We show the performance of the proposed radio link for signals with frequency hopping on a specific example.

For a quantitative assessment, we consider the simplest case K = 2. In this case, the output signal of the transmitter 1 is formed by two chains, the first of which consists of blocks 3 ₁ , 11 ₁ , and 4 ₁ connected in series, and the second of blocks 3 ₂ , 11 ₂ and 4 ₂ connected in series. Let the transfer take place. We choose in the current time the interval T ₀ . As indicated above, the time interval T ₀ is the transmission time at a level close to the maximum. The beginning of this interval on the time axis is taken to be zero, let the transmission coefficient of the first controlled AL 11 ₁ in this time interval [0, T ₀ ] have a value close to the maximum (minimum attenuation), which corresponds to the maximum value of the signal power at the tuning frequency of PGVK 4 ₁ . The indicated frequency is determined in the time span [0, T ₀ ] by the corresponding command from the first output of the BZRK 13. On the same time span [0, T ₀ ], the second chain works as follows: first, the transmission coefficient of the second steered ShA 11 ₂ has a value close to maximum (minimum attenuation), and decreases rapidly in time, so that by the middle of the time interval [0, T ₀ ], that is, T _0/2 , the transmission coefficient of the second controlled UA 11 ₂ has a value close to zero, then the transmission coefficient second controlled SHA 11 ₂ increases, approx approaching the maximum value, and at the moment T ₀ it becomes equal to the transmission coefficient of the first steered ShA 11 ₁ . Frequency tuning of the second PGVK _{2 April} determined time interval [0, T _0/2] corresponding command from the second output BZRK 13. At the beginning of the next time interval [T _0/2, T _0] is changed to another frequency in accordance with a command BZRK 13 and remains constant for a time duration of 2T ₀ or T _0/2 to (2T ₀ + T _0/2). Frequency tuning of the first PGVK April ₁ until time 3T _0/2 does not change, and transmitting the first managed January ₁₁ ShA coefficient abruptly decreases at time 3T _0/2 becomes close to zero. This corresponds to a change in signal power at a tuning frequency of the first PGVK 4 ₁ to the minimum possible. At a subsequent time interval 2T _0, namely [3T _{0/2 0} 7T / 2], the frequency is changed to another in accordance with a command from BZRK and 13 remains constant. Coefficient of transmitting the first managed SHA Jan. ₁₁ on the time interval [3T _0/2, 7T _0/2] varies from a value close to zero, to a value close to the maximum - [3T _0/2, 2T _0], is near the maximum - _[0 2T, 3T _0], and decreases to the minimum value - [3T _{0 0} 7T / 2]. Accordingly, the signal power also changes at the tuning frequency of the first PGVK 4 ₁ . The second chain over the time interval _[0 5T / 2, ₀ 9T / 2] operates similarly to the first time interval [3T _{0/2 0} 7T / 2], etc. Thus, the radiation at each frequency occurs in three stages: the first is the increase (increase) from the minimum value of the output voltage to close to the maximum, the second is the radiation when the output voltage is close to the maximum, and the third is the decrease in radiation (decline) from close to maximum to minimum. Moreover, the first and third stages have a duration of T _0/2 , and the second - a duration of T ₀ . Due to the preliminary synchronization and delay (delay circuit 14), reception is carried out in the second stage, that is, in time intervals corresponding to the radiation of maximum power at frequencies corresponding to the commands from the generator of the SRP transmitter 5 and the generator of the SRP receiver 10.

On figa and 9b are graphs of the dependence of the output voltages, respectively, for the first chain U1 (τ) and for the second on the second chain U2 (τ) of the transmitter 1. In accordance with the block diagram of Fig.6, the output voltage of the device is the sum of U (τ ) of these two voltages.

To determine the quantitative value of the gain, we assume that the gain of the attenuator varies according to the law U (τ, d):

where τ is the current time normalized to T ₀ ;

d is a parameter that determines the steepness of the fronts of the output voltage U (z, d) or its approximation to a rectangular pulse.

In graphical form, U (τ, d) is shown in FIG. 10. For d = 10, d = 16 and d = 20 in figure 10, three areas can be distinguished: the opening area (from minus 1 to minus 0.5), the area with the maximum transfer coefficient (from minus 0.5 to 0.5) and closing area (from 0.5 to 1).

As noted above, the prototype generates a signal in the form of a rectangular pulse at each frequency. The graph (see figure 3) shows a segment according to the formula:

This corresponds to the work of the prototype.

In the proposed device, a monotonic change in the signal at the output of the PGVK 4 ₁ , 4 ₂ leads to a narrowing of the radiation spectrum and significantly improves electromagnetic compatibility. To numerically illustrate this fact, Fig. 11 and Fig. 12 show the spectra of output oscillations s (ω, d) for U (τ, d) at d = 10, d = 16, d = 20, and also the spectrum of the rectangular momentum S (ω) for V (τ), here ω is the frequency.

Consider the results of Fig.11 - the near zone. The first main lobe of all three s (ω, d) and the rectangular pulse S (ω) is the same and has a width of 4π. The second lobe for s (ω, d) has a value of 1.5 to 3 times less than S (ω), its width is 2π, half the width of the main lobe. The third lobe for S (ω) is smaller than that of s (ω, d), more than an order of magnitude. Therefore, in the zone of the main lobe, the radiation in all four cases is the same, however, in the near zone, with minimal detuning, the proposed device has a significant gain.

The gain in large offsets can be determined by FIG. When detuning by τ = 38 (6 times in half of the main lobe) for d = 20, the attenuation of S (ω) is 1000 times, for d = 16, the attenuation of S (ω) is 3,000 times, for d = 10, the attenuation of S (ω) is 20,000 times, while for s (ω) the attenuation is much less and is 30 times.

Thus, compared with the prototype, the level of out-of-band emissions in the proposed device is significantly reduced. The proposed device works efficiently.

Information sources

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 communications, 2000. - 384 p.: Ill. ISBN-5-256-01392-0.

2. Torrievi D.J. Principles of Military Communication Systes-Dedham, MA: Artech House. Inc. 1981 (3P, 1986, No. 3 p. 13).

3. Aces G.I., Sivov V.A., Prytkov V.I. and others. Interference immunity of radio systems with complex signals. M .: Radio and communications, 1985, - 264 p.

4. Titz U., Schenk K. Semiconductor circuitry. Reference guide. Per. with him. - M .: Mir, 1982. - 512 p., Ill.

Claims (1)

A radio communication line for signals with a pseudo-random tuning of the operating frequency, comprising a transmitting and receiving parts, the transmitting part being a transmitter containing a serially connected information source and a first modulated signal source, as well as a transmitter pseudo-random sequence generator (PSP) and a first tunable generator of forced oscillations, moreover, the source of information is the input stage of the transmitter, and the output of the first tunable generator of forced oscillations - the output of the transmitter, in the receiving part there is at least one receiver containing a receiver PSP generator and a broadband filter connected in series, the input of which is the receiver input, a tunable bandpass filter and a signal demodulator, the output of which is the receiver output, characterized in that introduced into the transmitter - (K-1) modulated signal sources, K controlled broadband attenuators, (K-1) tunable forced-oscillation generators, control unit for broadband attenuates frames and a delay and separation block of the transmitter PSP code into “K” commands, while the inputs (K-1) of the modulated signal sources are connected to the input of the first modulated signal source, the outputs (K-1) of tuned forced oscillation generators are connected to the output of the first tunable generator forced oscillations, the outputs K of the sources of the modulated signal are connected to high-frequency inputs K of the corresponding controlled broadband attenuators, the outputs of which are connected to the information inputs To the corresponding of their tunable forced oscillation generators, the transmitter PSP generator output is connected to the input of the broadband attenuator control unit, the outputs of which are connected to the control inputs of the controlled broadband attenuators, respectively, in addition, the transmitter PSP generator output is connected to the input of the delay unit and dividing the transmitter PSP code into K ”commands, the outputs of which are connected to the control inputs of the corresponding tunable forced oscillation generators; introduced into the receiver is a delay circuit, the output of which is connected to the control input of the tunable band-pass filter, and the input is connected to the output of the receiver bandwidth generator.

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