Adaptive Equalization Algorithm And Implementation In Digital Microwave Communication

In mobile communication and high-speed wireless digital communication, inter symbol interference(ISI) introduced by multi-path effect, the limited channel bandwidth and the imperfectness of the channel, becomes a key factor that degrades the performance of communication. However channel equalization technique can overcome the influence of ISI. And adaptive equalizers have found wide applications for they can trace the variation of the channel.This thesis studies the adaptive equalization problems by focusing on the algorithm and the structure aspects. A thorough analysis is made on the three wildly used adaptive equalization algorithm of LMS,RLS and Kalman, and the relationships among them as well as their performance evaluation are given. A modified future coefficient filtering algorithms in the least mean squares (LMS) algorithm is proposed and the performance is evaluated. In the structure aspsect, analysis of the performance of the fractionally spaced adaptive decision-feedback equalizer is made by putting emphases on its local convergence property and error propagation.The implementation of the fractionally spaced adaptive decision-feedback equalizer with FPGA is also presented in the last of this thesis .