一种基于FFT算法M-APSK信号载波参数联合检测

随着卫星通信业务的发展,高阶调制技术逐渐应用于卫星通信中,但载波频率和相位偏差对诸如M-APSK等高阶调制信号的影响很大。在回顾载波同步算法理论的基础上,分析了载波频率和相位偏差对APSK信号系统的影响,采用了一种基于最大似然(ML)准则的数据辅助(DA)载波同步算法,并使用FFT快速运算和三线插值法,对频率偏差和相位偏差进行了联合检测。研究表明,该算法在同步性能和实现复杂度上的性能都比较优越。该算法对卫星通信高阶调制M-APSK信号的同步技术提供了一定的参考价值。

Joint detection of M-APSK signal carrier parameters based on FFT algorithm

With the development of satellite communication service, high order modulation technology is gradually applied to satellite communications. However, the carrier frequency and phase offsets exert enormous influence on the high order modulation signals such as M-APSK. Theory of carrier synchronization was firstly reviewed, and the impact of the carrier frequency and phase offsets on APSK analyzed. A data-aided(DA)carrier synchronization algorithm based on maximum likelihood(ML)was proposed, and the fast operation of FFT and triple-amplitude-line interpolation were used to jointly detect the carrier frequency and phase offsets. Simulation results show that the algorithm performs well on synchronization performance as well as realization complexity, which is helpful to promote the M-APSK signal synchronization technology for satellite communication high order modulation.