Multi-path slow frequency hopping signal anti-interference processing system

Abstract

The invention relates to a multi-path slow frequency hopping signal anti-interference processing system which comprises a shunt demodulation unit, a unique code capturing unit, a power deciding unit, a data processing unit and a decoding unit. According to the characteristics of the slow frequency hopping system, the system captures all service hops, judges the power magnitudes of the service hops, detects whether interference exists in received signals or not according to the capture result and the power judging result of each hop, sets data of the service hops with interference to be zero, and decodes phase-adjusted base band demodulation signals through the LDPC decoding method so that it can be ensured that decoding can still be correctly conducted under the condition that interference exists and the anti-interference capacity of the system can be improved; the system accumulates correlation values of multiple service hops within a time slot in the service hop related capturing process and calculates phase errors of the time slot according to the accumulated correlation values, and therefore the time slot phase capturing probability is greatly increased.

Description

technical field [0001] The invention relates to the technical field of communication anti-interference, in particular to an anti-interference processing system for multi-channel slow frequency hopping signals. Background technique [0002] In the environment of low signal-to-noise ratio and strong interference, how to ensure normal communication is the basic requirement of communicators, especially military communication. With the diversification of the interference patterns of the interfering party, the communication system needs to be able to effectively resist various interferences. Frequency hopping communication is currently the most widely used communication method in the field of communication anti-jamming. By using pseudo-random patterns to control the continuous hopping of carrier frequency to avoid interference signals and ensure the effective transmission of information in harsh wireless communication environments, Frequency hopping communication is widely used in...

AI Technical Summary

Problems solved by technology

Due to the inherent time jitter of the bit timing in the demodulation algorithm, phase synchronization is required for each hop to ensure the initial phase alignment of the signal entering the decoder, and it is necessary to solve the problem of low probability of unique code capture under low signal-to-noise ratio. On the other hand, LDPC coding is applied in the frequency hopping system. If a certain hop is interfered, the power of the interfering hop signal is very large, which will cause a decrease in decoding performance and reduce the anti-interference performance of LDPC decoding in the frequency hopping system.

[0004] In the current slow frequency hopping communication system, in addition to avoiding interference by using the characteristics of signal carrier frequency hopping, the application of LDPC coding and decoding technology can further improve the interference tolerance of the system, but if a hop is interfered, the signal power of the interference hop is very low Large, it will cause the decoding performance to decline, and reduce the anti-interference performance of LDPC decoding in the frequency hopping system. It is necessary to deal with the interfered signal entering the LDPC decoding module to improve its anti-interference performance

Therefore, how to judge whether the current jump is interfered is very important. Most of the current researches only use the power of the signal to judge the interference. When it is relatively low, the capture probability of the frequency hopping signal decreases, and the capture of the unique code is carried out within the entire hop range, and the probability of accidental capture is relatively high. It is necessary to use some auxiliary information and processing methods to reduce the probability of the system's false capture; The processing of channel frequency hopping signals adopts the method of processing each channel separately, and the hardware takes up a lot of resources, so it is necessary to further reduce the resources occupied by the system to reduce the cost of the equipment

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