基于LDPC码的低截获概率信号设计与仿真

Design and simulation of low probability of interception signals based on LDPC codes

针对开放无线信道中存在的安全通信问题,提出一种低截获的安全通信方案。采用LDPC(low-density parity-check)码对保密信号进行编码,以增强其抗干扰能力,再使用具有循环平稳特征的大信号对保密信号进行掩盖,提高其抗截获能力。利用LDPC码的编译码原理和大信号掩盖技术设计低截获概率信号,对仿真试验的结果进行分析,并对保密信号的解调性能进行仿真分析。研究表明:当大信号和保密信号的功率比为15 dB时,盲检测得到保密信号的概率不超过0.01;抗截获能力得到提高的同时,解调误码率仍在可接受的范围之内。

Aiming at the problem of secure communication in wireless channel,a secure communication method with low probability of interception was proposed.The low-density parity-check(LDPC)code was uesd to encode the transmitted bits,to enhance the ability of confidentiality.A strong signal with cyclostationarity was used to mask the transmitted signal to improve the anti-interception ability.A low probability of intercept signal was designed by combining LDPC code with the strong-signal masking technology,and the simulation analysis of the performance of the transmitted signal was performed.The research results reveal that when the power ratio of strong signal to transmitted signal is 15 dB,the probability of transmitted signal obtained by blind detection is less than 0.01.The anti-interception ability is improved while the demodulation bit error rate is still at the acceptable range.