一种MFSK信号的软解调Turbo译码算法  

A Soft Demodulation Turbo Decoding Algorithm for MFSK Signal

作　　者：梁立林 LIANG Lilin(No.10 Institute of CETC,Chengdu Sichuan 610036,China)

机构地区：[1]中国电子科技集团公司第十研究所,四川成都610036

出　　处：《通信技术》2024年第3期251-254,共4页Communications Technology

摘　　要：为了提高短波通信中多进制频移键控(Multiple Frequency Shift Keying,MFSK)信号的传输性能,提出了一种适用于MFSK信号的软解调Turbo译码算法。利用快速傅里叶变换(Fast Fourier Transform,FFT)计算MFSK调制频率对应的信号幅值,并结合增强型Turbo码结构,编码时将MFSK信号调制频率与Turbo编码状态形成映射关系,译码时利用软解调信号幅值直接计算对数分支度量,减少了比特似然信息计算的误差。仿真结果表明,相比于常规软比特解调译码算法,所提算法提高了MFSK信号软解调Turbo译码算法的误比特率(Bit Error Rate,BER)性能。In order to improve the transmission performance of MFSK(Multiple Frequency Shift Keying)signal in shortwave communications,a joint soft demodulation and enhanced Turbo decoding algorithm for MFSK signal is proposed.FFT(Fast Fourier Transform)is used to calculate the signal amplitude corresponding to the MFSK modulation frequency.Combined with the enhanced Turbo code structure,the mapping relationship between the modulation frequency of the MFSK signal and the Turbo coding state is formed at encoding time and the soft demodulation signal amplitude is used to directly calculate the logarithmic branch metric at decoding time,which reduces the error in the calculation of the bit likelihood information.Compared to the conventional soft demodulation Turbo decoding algorithm,the simulation results indicate that the proposed algorithm improves the BER(Bit Error Rate)performance of soft demodulation Turbo decoding algorithm for MFSK signal.

关 键 词：FFT MFSK 软解调 TURBO码 BER 

分 类 号：TN911[电子电信—通信与信息系统]