论文部分内容阅读
为改善系统性能,提出一种将近似最大似然法与导频相结合的方法。首先对近似最大似然法的定时函数,设定门限,以此确定一个粗时偏估计范围,再利用导频的定时函数,按一定规则,在该范围内搜索出精确的时偏,同时FFT之前记录下的对应于该时刻的频偏即为估计出的系统频偏。仿真表明,该算法能改进多径环境下的同步性能,尤其是在首径非能量最大径的环境下,提高系统的性能。
To improve the system performance, a method of combining the approximate maximum likelihood method with the pilot is proposed. First, the approximate maximum likelihood method of the timing function, set the threshold, in order to determine a rough time-bias estimation range, and then use the pilot’s timing function, according to certain rules, search within the range of precise time-offset, and FFT The recorded frequency offset corresponding to the moment is the estimated frequency offset of the system. The simulation results show that the proposed algorithm can improve the synchronization performance under multi-path environment, especially in the environment with the largest non-energy path and the highest system performance.