Research And Realization Of MLSE Based On ISI Channels

By the past several decades, there are big changes in the field of telecommunication technology. The telecommunication technology is used broadly. It has changed people's life style, and moves the society economic greatly. There are more and more needs of communication with each other at any time, any where, and with any kind of method. The third generation (3G) of mobile communication become reality. The next step is 4G of more capacity, faster rate and powerful function. The future telecommunication services not only the multimedia, but also the service of anywhere and global services. So the capacity, rate and quality of telecommunication becomes more and more important. This is also the hot spot in the field of telecommunication technology. Maximum likelihood sequence detection (MLSE) is broadly use in the digital communication system to estimate the transferred data through the ISI channel with noise. This kind of technology's realization is challengeable when the channel is unknown and fast time variable. It is not allowed high symbol errorate in the practical design of digital communication system that because of ISI (Inter symbol interference). In the general, there is ISI in the most practical digital channels. This paper introduces MLSE technology to the ISI channels in order to decrease the symbols error and presets our conclusion. We simulate with telecommunication simulation technology and prove the conclusion at possible application circumstances. In chapter one, it summarizes the development and application of MLSE technology inside and outside of China and shows MLSE technology's characteristics and Viterbi algorithm. In later several chapters, MLSE technology and implementation of Viterbi algotithm are studied in detail with theories analysis and computer simulation. The principle of MLSE technology and Viterbi algorithm is described in chapter 2. It analyzes the transferred data and reseived data and presents the system model. Because of the ISI in the channel, the MLSE technology is proposed to estimate the transferred data according to the statistics of received data. Chapter3 is based on the chapter 2. It is detailed to describe the implementation of MLSE technology in the known ISI channel and Viterbi algotithm. There are some computer simulations and analysis about implementation of this kind oftechnology. It is indicated that Viterbi algorithm is applicable at large scale and is the best method of the sequence estimation in the ISI channels. In chapter 6, the summary of this thesis is made and review all works. The questions still in this subject are discussed, and the further development and research is prospected.