基于LMS算法改进Cupo相位抖动补偿方法

为了增加FIR-ALE(Finite Impulse Response-Adaptive Linear Enhancer)相位噪声补偿系统的补偿能力,本文基于LMS算法对Cupo的FIR-ALE系统进行改进,并对8PSK调制方式下的信号进行了Matlab仿真,通过对信号功率谱、误比特率以及星座图的分析,对比了两种方法.仿真结果表明,改进后的系统对于幅度为5°、频率为120 Hz的相位抖动,能够将抖动衰减25 dB左右;对于幅度为15°、频率为25 Hz的相位抖动,改进后的LMS系统能将抖动衰减35 dB左右.而且,随着相位抖动幅度的增大,改进的LMS方法的补偿能力同Cupo的FIR-ALE方法比较,性能逐渐提高.

Improvement of Cupo' s phase jitter compensation method based on LMS algorithm

An improved method for FIR-ALE (Finite Impulse Response-Adaptive Linear Enhancer) based on LMS algorithm is discussed in this article. The simulation of 8PSK modulation signals under Matlab is also illustrated. Comparison of these two kinds of methods can be seen clearly under the simulation of the power spectrums, BER, and constellation. The simulation results prove that the improved LMS system can deduce the phase jitter by almost 15dB, when the jitter amplitude is 5o and the frequency is 120Hz, and the system can deduce the phase jitter by 35dB, when the jitter amplitude is 15o and the frequency is 25Hz. And what is more important is that the compensation ability of the improved LMS method compared with the FIR-ALE method is enhancing with the increasing of jitter amplitude.