基于混沌序列的MIMO-OFDM雷达通信一体化波形设计

Integrated MIMO-OFDM radar and communication waveform design based on chaotic sequence spread spectrum

为了解决多输入多输出的正交频分复用(multiple input multiple output orthogonal frequency division multiplexing,MIMO-OFDM)雷达通信一体化信号波形由于通信信息的不确定性导致模糊函数旁瓣水平较高以及系统雷达探测能力较差的问题,提出利用混沌序列对通信信息进行直接扩频。但普通单级混沌序列具有保密性低,可用数量少,容易被破解的缺点。因此采用一种基于加权算法优化的混合型级联混沌序列对通信信息进行扩频调制,然后再通过MIMO-OFDM一体化系统进行传输。由仿真结果可知,加权后的级联混沌序列相关性和误码率性能较m序列和Gold序列更好,经此序列扩频后的一体化信号模糊函数旁瓣水平会更低,故该一体化波形雷达探测性能更佳。且混沌序列越长,信号波形雷达探测能力越好。

Due to the uncertainty of data information in MIMO-OFDM joint radar and communication waveform,the sidelobes level of fuzzy function will be very high and the detection ability of JRC system is poor.To solve these problems,this paper proposes to use chaotic sequence for direct spread spectrum of communication information.But common chaotic sequence has the disadvantages of low security,few available quantity and easy to crack.Therefore,a hybrid cascade chaotic sequence optimized based on weighted algorithm is proposed.This sequence is adopted to carry out spread spectrum modulation for communication information,which transmits it through the MIMO-OFDM integrated system.Simulation results show that aperiodic correlation performance and bit error rate(BER)of the weighted cascade chaotic sequence is better than that of the m sequence and the Gold sequence.And sidelobe level of the integrated signal after spread spectrum of this sequence is lower.So radar detection performance of the integrated waveform designed in this paper is better.And the longer the chaotic sequence,the better the radar detection ability of waveform.