单信道时频重叠双信号的码速率估计方法

Method for Symbol Rate Estimation of Single-Channel Time-Frequency Overlapped Two-Signal

提出一种基于四阶循环累积量的功率谱分析算法,用于解决单信道时频重叠双信号的码速率估计问题。通过计算循环频率轴上不同频率处的四阶循环累积量值,得到双信号在各自循环频率处的脉冲,对脉冲序列进行功率谱分析,提取隐含的周期性从而估计双信号的码速率。算法适用于多种数字调制类型的通信信号,且在低信噪比下也具备较好的估计性能。理论分析和仿真试验结果均证明了算法的正确性和有效性。

To solve the problems in symbol rate estimation of time-frequency overlapped two-signal in the single-channel, the algorithm of the power spectrum based on fourth-order cyclic cumulants is presented. Through computing the fourth-order cyclic cumulants of received signals at different frequencies, the impulse of two-signal at cyclic frequency is received, and then the power spectrum of impulse sequence is analyzed to abstract the connotative periodicity to estimate the symbol rate. The algorithm could be applied to estimate the common digital modulation type, and also have a good capability in low SNR. Theoretical analysis and experiment results both verify that the algorithm is correct and efficient.