为降低多调制指数连续相位调制 (Multi-h CPM)信号解调和级联译码的复杂度和时延, 提出了一种适用于多进制部分响应 Multi-h CPM信号的低复杂度软输出维特比 (LC-SOVA)算法。针对倾斜相位 (TP)+频率脉冲截断 (FPT)低复杂度 Multi-h CPM解调, 在维特比检测中对每个状态存储并不断更新符号软信息, 通过舍弃度量较小的路径来降低更新软信息的运算量, 且软信息更新过程可以并行处理, 复杂度降低一半, 时延与维特比算法等价。仿真结果表明, 所提 LC-SOVA算法具有通用性, 适用于多进制部分响应 Multi-h CPM信号的软信息计算, 在级联低密度奇偶校验码 (LDPC)系统中, 该算法与 Max-log-MAP算法相比信噪比损失几乎可以忽略不计。

To reduce both the complexity and the delay of demodulation and decoding for Multi-h Continuous Phase Modulation(Multi-h CPM) signal, a Soft Output Viterbi Algorithm with Low Complexity(LC-SOVA) isproposed, which can be utilized to M-ary Multi-h CPM signal with partial phase response. Based on the tilt phase-frequency(FPT) and pulse truncation low complexity demodulation of Multi-h CPM signal, the symbol soft information in the Viterbi states is stored and updated by discarding the smaller path to reduce the computational complexity. In the proposed algorithm, the soft information update process can be processed in parallel with half computation compared with the existing SOVA algorithm, and the time delay is equivalent with that of the Viterbi algorithm. The simulation results show that the proposed LC-SOVA algorithm is generally applied to any Multi-h signal and its performance degradation can be neglected compared to the Max-log-MAP algorithm.