Research Of Adaptive Equalization In High Speed Mobile Wireless Channel

First of all, this paper does a lot of research on the characteristics of mobile wireless channel, especially on the small-scale fading. Simulation of multipath fading channel is also presented. Multipath effect and Doppler shift are two troublesome problems in mobile wireless channel. Inter symbol interference (ISI) caused by multipath effect is a major factor to degrade the performance of modern digital communication systems. Adaptive equalization is an important technique to combat the ISI in time varying mobile wireless channel. This paper focuses on Maximum Likelihood Sequence Estimate (MLSE), based on the widely study of basic principle, structure and algorithms of adaptive equalization.When MLSE is put into real practice, decision delay and computational complexity are two problems to be solved. The decision delay is terribly serious in high speed mobile wireless channel. Many improvement methods of MLSE are discussed. This paper mainly concerns two of them, i.e., PSP and CBSE. Per-Survivor-Processing (PSP) is an effective way to solve the problem of decision delay. Cluster Based Sequence Estimation (CBSE) is an effective solution to reduce the computational complexity of classic MLSE.When those schemes are used in the mobile wireless communication system, especially in the high speed mobile environment, some problems come out and solutions to them are proposed in this paper. Analysis of performance and complexity are also presented, combined with simulation.