中文摘要：

针对FH／MFSK系统，提出一种MFSK信号的M维软解调能量信息，作为译码器软输入的方法，避免了近似比特对数似然信息（LLR）的计算，并结合卷积码，给出了相应的软译码算法。理论推导了采用该算法的FH／MFSK系统在AWGNC和Rayleigh衰落信道下抗PBNJ性能，给出了BER的上界闭合表达式。计算机仿真验证了理论推导的正确性，并与近似比特LLR和硬判决2种译码器输入信息的FH/FSK系统进行对比，证明该算法获得了明显的抗PBNJ处理增益。

英文摘要：

For frequency hopping/M-ary frequency shift keying （FH/MFSK） Systems, combining convolutional coding, a soft decoding algorithm is proposed by adopting M-dimensions energy information for the soft-demodulation of MFSK signals as soft input of decoder, avoiding the approximate bit logarithm likelihood ratio （LLR） calculation. The theoretical performance of the proposed algorithm is analyzed for FH/MFSK systems in the presence of partial-band noise jamming （PBNJ） over additive white Gaussian noise （AWGN） and Rayleigh fading channels. The upper bound for closed-form expressions of BER performance are derived and validated by computer simulations. The results show that the proposed algorithm obtains obvious anti PBNJ processing gain compared to the approximate bit LLR and hard decision.