基于双正交Fourier变换的多进制Chirp-rate调制的解调算法

Demodulation Algorithm for M-ary Biorthogonal Chirp-rate Modulation Based on Fourier Transform

针对多进制Chirp-rate调制的通信系统解调算法由于基函数的正交性差导致实现复杂且性能不佳的特点,提出采用基于双正交Fourier变换的解调算法多进制的Chirp-rate调制行正交解调,解决了不同调频率的Chirp信号相互正交的问题,解调后可以得到信号调频率密度谱。BFT算法特点是信号在双正交基下展开,对多LFM信号分析不需要搜索,没有交叉项,特别适合对不同调频斜率组成的多LFM信号进行调频斜率分析。仿真表明其基于双正交Fourier变换的多进制Chirp-rate键控调制的解调算法具有接近MFSK误码率的性能。

According to the communication system and demodulation algorithm for M-ary Chirp-rate modulation due to the orthogonality of basis functions due to poor implementation complexity and poor performance, put forward using Chirp-rate modulation demodulation algorithm for orthogonal demodulating M-ary double orthogonal Fourier transform based on Chirp, to solve the signals of different frequency rate are orthogonal, the demodulated signal was FM density spectrum. The characteristics of the BFT algorithm is carried out in two orthogonal signal, the analysis on the multi LFM signal does not need to search, no cross terms, especially suitable for the analysis of multi LFM signal modulation slope composed of different frequency rate. Simulation results show that the demodulation algorithm for M-ary biorthogonal transform Chirp-rate key Fourier modulation based on BER performance close to MFSK.