Research On The Adaptive Equalization Of Wireless Communication

Equalization is an efficient technique which can eliminate Inter-symbol interference(ISI) owing to non-ideal channel.Adaptive equalization may decrease ISI and noise, reduce the bit error ratio and track time-changing channel. Adaptive equalization need to send for training series.It will occupy system bandwidth and reduce the efficiency of the system. Blind equalization can resolve the question effectively.On the basis of studying on wireless channel, this thesis discusses adaptive equalization algorithms, including Least Mean Square(LMS) algorithm and Recursive-least-square(RLS)algorithm. Tongue-Like Curve adaptive equalization algorithm is particularly researched in this thesis. We propose an adaptive equalization algorithm which considers the relevance of importation of signal and error. In order to stronger trace ability, the proposed method adds the fore step. Compared with primarily algorithm, the proposed method has both faster converging speed and stronger tracing ability. Next we study the Const Modulus Algorithm(CMA).A new variable step-size CMA blind equalization algorithm is given. The simulation results proved to show that the equalization effects has better in new algorithm than in tradition CMA algorithm.