RU2324287C2 - Method for provision of technical availability of radio lines with frequency hopping - Google Patents

Abstract

FIELD: radio communications.

SUBSTANCE: at the transmitting end information packets are formed by adding to them destination "address" and service information, transmitter carrier frequency is tuned, radio signal is emitted to the receiving end of radio link where the transmitted signal is received simultaneously at all frequencies, after appropriate conversion the information signal is supplied to the information receiver; at the receiving end of radio link control receivers check frequencies for interference along with radio signal receiving, generate control information to tune the transmitter at the transmitting end of radio link to the frequency that is free from interference, form information packets by adding to them the control information to tune the transmitter at the transmitting end of radio link, tune carrier frequency of the transmitter at the receiving end of radio link, modulate carrier frequency of the transmitter at the receiving end by the formed information packet, emit the obtained radio signal to the transmitting end of radio link where it is received along with radio signal transmitting simultaneously at all frequencies, the control information is retrieved to tune the transmitter at the transmitting end of radio link to a frequency that corresponds to code of the next cycle of the Pseudo-Random Sequence (PRS), which is free from interference; at that, at the receiving end of radio link control receivers, after signal receiving, provide for forecasting of signal-to-noise ratio variation at the frequencies that correspond to codes of the next cycle of all PRSes, analysis signal-to-noise ratio, and tuning to the nearest frequency, which is free from interference, and no signal-to-noise degradation is forecasted.

EFFECT: provision of required technical availability due to forecasting of signal-to-noise ratio variation at inputs of control receivers.

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Description

The invention relates to the field of radio communications, namely, the transmission of information by signals with pseudo-random tuning of the operating frequency (MHF).

The proposed method can be used in duplex radio links with frequency hopping of various lengths, operating in the common frequency band with radio facilities of various affiliations and with different principles of operation.

A known method of transmitting information described in [1]. It can be used only in short-haul radio links, the interference environment at the ends of which is identical. For long-distance radio links, the interference environment at the receiving and transmitting ends will be different, which can lead to the choice of the transmission frequency affected by the interference at the receiving end and communication failure.

The disadvantage of this method is to determine the signal-to-noise ratio only at the current moment in time, while the signal-to-noise ratio is not predicted.

The closest in essence to the claimed method is the method described in [2]. The essence of the method includes dividing the input signal into blocks at the transmitting end, rearranging the carrier frequency of the transmitter in accordance with the code of one of two or more pseudorandom sequences, modulating the carrier frequency of the transmitter with an appropriate packet and then radiating it into space, receiving a signal at the receiving end of the radio line simultaneously at all frequencies according to the codes of pseudo-random sequences, the choice of the frequency channel through which the transmission was made, the signal conversion on the intermediate the exact frequency, amplification, demodulation, packet decoding and supply of the information signal to the terminal device, at the receiving end of the radio line simultaneously with the reception of the information signal, receive at all frequencies corresponding to subsequent clock ticks of the codes of pseudorandom sequences, monitor the level of interference at these frequencies and in the event of interference at the controlled frequency of the work program, control information is generated to reorganize the correspondent transmitter to the frequency with the lowest interference level, compress information packets by attaching control information to the information signal blocks, modulate the carrier frequency of their transmitter with a corresponding information packet, emit the modulated carrier frequency into the space at the transmitting end simultaneously with the radiation of the modulated carrier frequency into space, receive the information signal simultaneously at all frequencies according to pseudorandom codes sequences, the choice of the frequency channel over which the transmission was made, p converting the signal to an intermediate frequency, with its subsequent amplification and demodulation, decoding the packet with the allocation of an information signal block arriving at the terminal device and a block containing information on controlling its transmitter for its subsequent tuning to the frequency with the lowest noise level, optimal for the receiving end .

The disadvantage of the prototype is to determine the signal-to-noise ratio only at the current moment in time, while the signal-to-noise ratio is not predicted.

The technical result of the claimed method is to provide the required technical readiness by introducing prediction of changes in the signal-to-noise ratio at the inputs of the control receivers, as a result of which it becomes possible to switch the radio communications to frequencies at which the deterioration of the signal-to-noise ratio is not predicted.

The specified technical result is achieved by the fact that in the method of ensuring the technical availability of radio lines with pseudo-random frequency tuning, including forming information packets at the transmitting end by dividing the information signal received from the information source into blocks of a given length, to which the correspondent "address" and service information are added, tuning the carrier frequency of the transmitter to a frequency corresponding to the code of the current clock of one of two or more pseudo-random sequences, which I for this measure is operational, modulating the carrier frequency of the transmitter with the generated information packet and subsequent radiation of the received radio signal to the receiving end of the radio line, at the receiving end of the radio line receiving the transmitted from the transmitting end of the radio signal simultaneously at all frequencies corresponding to the codes of the current clock of all pseudorandom sequences, conversion to intermediate frequency, amplification, demodulation, decoding of the received information packet at the "address" recorded in the packet, at I receive the information signal at the information receiver, at the receiving end of the radio line, simultaneously with the reception of the radio signal, the control receivers monitor the presence of interference at frequencies corresponding to the codes of the subsequent clock of all pseudorandom sequences, and in the case of interference at a controlled frequency corresponding to the code of the subsequent clock of the working pseudorandom sequence of the transmitting end form control information for the restructuring of the transmitter located at the transmitting end of the radio line, to the frequency corresponding to the code of the subsequent clock of one of the monitored pseudo-random sequences, where interference is absent, by changing the pseudo-random sequence at the transmitting end, information packets are formed, to which control information is added to the tuning of the transmitter located at the transmitting end of the radio line, the carrier frequency of the transmitter is tuned, located at the receiving end of the radio line, at a frequency corresponding to the code of the current measure of one of two or more pseudo-random poses of investigations, modulate the carrier frequency of the transmitter located at the receiving end, formed by the information package, emit the received radio signal to the transmitting end of the radio line, at the transmitting end simultaneously with the radiation of the radio signal receive the transmitted radio signal from the receiving end simultaneously at all frequencies corresponding to the codes of the current clock of all pseudorandom sequences, convert to an intermediate frequency, amplify, demodulate, decode the received packet of information recorded in the packet " address ", control information is allocated for tuning the transmitter located on the transmitting end of the radio line, the received control information is fed to the transmitter on the transmitting end of the radio line to be tuned to a frequency corresponding to a subsequent clock code of that of the pseudorandom sequences at which there is no interference, in the absence of interference on the monitored the frequency corresponding to the code of the subsequent clock of the working pseudo-random sequence of the transmitting end or the presence of interference at all monitored For this reason, the control information is not generated and the pseudo-random sequence is not changed at the transmitting end, and at the receiving end of the radio line after receiving the radio signal and checking for interference at frequencies corresponding to the codes of the subsequent clock of all pseudo-random sequences, control receivers predict the change in the signal-to-noise ratio at frequencies corresponding to codes of the subsequent clock of all pseudo-random sequences, and analysis of the signal-to-noise ratio, often oh, which rearrangement is carried out with deterioration of the signal-to-noise at frequencies corresponding to all codes of a subsequent cycle of pseudorandom sequences is the closest frequency at which interference is absent and the deterioration of the signal-to-noise ratio is not expected.

The claimed method is illustrated by drawings, which show:

figure 1 is a structural diagram of a transceiver device explaining the claimed method of ensuring technical availability of radio links with pseudo-random frequency tuning;

figure 2 is a variant of the structural diagram of a device for probabilistic forecasting.

The implementation of the claimed method is as follows.

The transmission of information simultaneously on several radio links with orthogonal programs significantly increases noise immunity and reduces the number of required frequencies. However, the simultaneous operation of several transmitting devices in one object worsens the internal electromagnetic compatibility (EMC) of electronic equipment. More effective from this point of view is the algorithm for selecting one frequency channel from several offered by radio links with their own tuning programs, in which there is currently the least interference level. Such an algorithm for the operation of a radio frequency hopping system can be implemented when several transceivers operate, in particular in two orthogonal programs with carrier frequency control, and consists in the fact that the transmitter operates in one of several programs, and reception is carried out immediately for all. In addition, the presence of interference at frequencies that will be set by each program after several jumps from the current frequency is monitored, and in the event of interference at a controlled frequency of the work program, the transmitter tunes to the frequency set by the backup program. For radio links with long-range frequency hopping, interference level control is carried out at the receiving end of the radio link. Based on the control results, control information is generated, which is transmitted to the transmitting end in order to adapt the transmission frequency to the interference situation at the receiving end. The receiver of the correspondent, including receivers operating according to the same programs, emits a useful signal according to the feature contained in the service part of the packets transmitted by one of the programs. At the same time, at the receiving end of the radio link after receiving the signal by the control receivers, a deterioration of the signal-to-noise ratio is predicted at frequencies corresponding to the codes of the subsequent clock of all pseudorandom sequences. An analysis is made of the signal-to-noise ratio, when the signal-to-noise ratio deteriorates at frequencies corresponding to the codes of the subsequent clock of all pseudorandom sequences, tuning to the nearest frequency is carried out, at which there is no interference and the signal-to-noise ratio is not predicted.

Information transmission devices at both ends of the radio link are the same (Fig. 1) and contain: a pseudo-random sequence generator (GPS) unit 1, a transmitter 2, a packet forming and decoding device 3, receivers 4.1-4.K, a comparison circuit 5, control receivers 6.1- 6.K. At the transmitting end of the radio link, the GPS unit 1 generates K pseudo-random sequences. On command from the packet forming and decoding device 3, the GPS unit 1 connects the necessary pseudo-random sequence (PSP) to the transmitter 2 and it transmits a packet formed by the packet forming and decoding device 3. At the same time as transmitting the packet, receivers 4.1-4.K produce receiving a radio signal simultaneously on all K frequency channels, transfer to an intermediate frequency, amplify and demodulate. The demodulated signals are fed to a packet forming and decoding device 3, in which it is concluded which channel is being transmitted and a packet is decoded, moreover, one part of the packet constituting the information signal block will be output from the device and the other part containing control information, to the input of GPSSP 1 for controlling the tuning of the transmitter to a frequency specified by one of the K programs of GPSSP 1. At the receiving end of the radio line simultaneously with receivers 4.1-4.K, which receive the information signal , Control receivers 6.1-6.K analyzed signal-to-noise ratio on frequency channels corresponding codes SRP subsequent cycles. In probabilistic forecasting, the signal-to-noise ratio at the outputs of the control receivers 6.1-6.K is continuously evaluated. If the signal-to-noise ratio tends to a value exceeding the allowable limits of the predetermined first minimum or first maximum values of the signal-to-noise, an alarm is issued about the deterioration of the signal-to-noise ratio at a controlled frequency by the display unit 7.1.7. Further analysis of the signal-to-noise ratio is performed in comparison circuit 5. Comparison scheme 5 evaluates the signal-to-noise ratio at the outputs of probabilistic forecasting devices 7.1-7.K and, when the signal-to-noise ratio deteriorates at the frequency specified by the GPS work program 1, generates control information on tuning the correspondent transmitter to the frequency specified by one of the backup GPS programs 1, at which the signal-to-noise ratio deterioration is not predicted. If at the working frequency channel the deterioration of the signal-to-noise ratio is not predicted, or all of the proposed GPS 1 frequency channels turned out to be occupied by interference, then the SRP at the transmitting end is not changed. The control information is supplied to the packet forming and decoding device 3, where information packets are formed by attaching control information to the information signal blocks, the carrier frequency of the transmitter 2 is modulated with the corresponding information packet, and the simulated carrier frequency is emitted into space.

The forecasting process can be implemented by UVP 7.1-7.K described in [3] (p. 158-159 Fig. 17). UVP is designed to detect and signal the deterioration of the signal-to-noise ratio at the outputs of the control receivers 6.1-6.K. Alternatively, it can be performed according to the scheme shown in figure 2.

In probabilistic forecasting, the changing values of the signal-to-noise ratio at the outputs of the control receivers 6.1-6.K are continuously evaluated. At the first stage, using the switching and measuring unit 7.1.1, the signal-to-noise ratio values issued by the control receiver are compared with the first minimum and first maximum values of the signal-to-noise ratio of the input signal. The obtained values are stored in the memory cells of the 7.1.2 memory block, and are also multiplied by the weight coefficients of the 7.1.3 block. Next, a forecast is made of the deterioration of the signal-to-noise ratio at a controlled frequency with the help of blocks for calculating the probabilistic characteristics of a priori information BV1 7.1.4 and a block for calculating conditional a posteriori probabilities BV1 7.1.5. If the value of the signal-to-noise ratio tends to a value exceeding the allowable limits of the predetermined first minimum or first maximum values of the signal-to-noise ratio of the input signal, then a signaling of the deterioration of the signal-to-noise ratio at a controlled frequency is indicated by the indication unit 7.1.7. At the same time, a signal is sent to the output of the device to the comparison circuit for further analysis.

Thus, the technical result is achieved by introducing a process for predicting changes in the signal-to-noise ratio at frequencies corresponding to the codes of the subsequent clock of all pseudorandom sequences for a certain time interval, as a result of which it becomes possible to switch the radio communications to frequencies at which noise is absent and signal ratio deterioration Interference is not predicted.

Information sources

1. "Inventions (applications and patents)." Bulletin No. 35, 1997, a description of the invention to the patent of the Russian Federation No. 2099886 "Method for transmitting information in radio lines with pseudo-random tuning of operating frequencies and a device that implements it."

2. Patent for the invention "A method for transmitting discrete information in a radio line with pseudo-random tuning of the operating frequency and a device that implements it." Auto St RF №2178237, Н04В 1/713, 2002

3. Technical diagnostic tools: Reference book / V.V. Klyuyev, P.P.Parkhomenko, V.E. Abramchuk and others; Under the total. ed. V.V. Klyueva. - M.: Mechanical Engineering, 1989 .-- 672 p., Ill.

Claims (1)

A method for ensuring the technical availability of radio lines with pseudo-random frequency tuning, including the formation of information packets at the transmitting end by dividing the information signal coming from the information source into blocks of a given length, to which the "address" of the correspondent and service information are added, tuning the transmitter carrier frequency to the frequency corresponding to the code the current measure of one of two or more pseudo-random sequences, which is operational for a given measure, carrier modulation the transmitter at the receiving end of the radio line, at the receiving end of the radio line, receive the radio signal transmitted from the transmitting end at the same time at all frequencies corresponding to the codes of the current clock of all pseudorandom sequences, converting to an intermediate frequency, amplifying, demodulating, decoding the received a packet of information at the "address" recorded in the packet, supplying an information signal to the information receiver, at At the receiving end of the radio line, simultaneously with the reception of the radio signal, the control receivers monitor the presence of interference at frequencies corresponding to the codes of the subsequent clock of all pseudo-random sequences, and in the case of interference at the controlled frequency corresponding to the code of the subsequent clock of the working pseudorandom sequence of the transmitting end, generate control information for tuning the transmitter, located at the transmitting end of the radio line, at a frequency corresponding to the code of the subsequent clock cycle one one of the monitored pseudo-random sequences without interference, by changing the pseudo-random sequence at the transmitting end, information packets are formed, to which control information is added for tuning the transmitter located on the transmitting end of the radio line, tuning the carrier frequency of the transmitter located on the receiving end of the radio link on the frequency corresponding to the current measure code of one of two or more pseudo-random sequences modulate the carrier frequency of the transmitter and located at the receiving end, formed by the information packet, the received radio signal is emitted to the transmitting end of the radio line, at the transmitting end, simultaneously with the radiation of the radio signal, the radio signal transmitted from the receiving end is simultaneously received at all frequencies corresponding to the codes of the current clock of all pseudorandom sequences, converted to an intermediate frequency, amplify, demodulate, decode the received information packet at the "address" recorded in the packet, allocate control information for tuning the transmitter located at the transmitting end of the radio line submits the received control information to the transmitter of the transmitting end of the radio link for tuning to a frequency corresponding to the next-cycle code of that of the pseudorandom sequences, where interference is absent, in the absence of interference at a controlled frequency corresponding to the subsequent-cycle code of the working pseudo-random the sequence of the transmitting end or the presence of interference at all controlled frequencies, the control information is not formed and the change of ps a random sequence is not produced at the transmitting end, characterized in that at the receiving end of the radio line after receiving the radio signal and checking for interference at frequencies corresponding to the codes of the subsequent clock of all pseudorandom sequences, the control receivers predict the change in the signal-to-noise ratio at frequencies corresponding to the codes of the subsequent clock of all pseudo-random sequences, and analysis of the signal-to-noise ratio, while the frequency at which when the signal-to-noise ratio worsens at frequencies corresponding to the codes of the subsequent clock of all pseudo-random sequences, the closest frequency is at which noise is absent and the signal-to-noise ratio deterioration is not predicted.

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