非数据辅助的多指数连续相位调制信号的载波频率估计算法

Non-data aided carrier frequency estimation algorithm for multi- h CPM

针对多指数连续相位调制(Multi-h CPM)信号的载波频率估计困难且算法复杂的问题,将仅仅适用于单指数CPM信号的载波频率估计算法进行改进,提出了一种适用于Multi-h CPM信号的非数据辅助的载波频率估计算法。基于最大似然准则获得Multi-h CPM信号载波频率的估计,为了有效地界定文中算法性能,最后推导了Multi-h CPM信号的载波频率估计算法的修正Cramer-Rao限。仿真结果表明:该算法适用于全响应和部分响应的Multi-h CPM信号,其载波频率估计的性能良好且对符号定时偏差和调制指数同步偏差不敏感。

To solve the difficulty and complexity of carrier frequency estimation of multi-h Continuous Phase Modulation （CPM）, a non-data aided carrier frequency estimation algorithm for multi-h CPM was proposed. This algorithm is based on existing earrier frequency estimation algorithm only for single-h CPM. The carrier frequency estimation was obtained using the maximum likelihood principles. Then, a modified Cramer-Rao bound for multi-h CPM was deduced for evaluating the performance. Simulation results show that the proposed algorithm is suitable for full response and partial response multi-h CPM; it has good performance in carrier frequency estimation and is not sensitive to the timing offset and modulation index offset.