Researches On Performance For Pre-Equalized Orthogonal Frequency Division Multiplexing Wireless Communication Systems

Wireless communications is undergoing a key period.The major challenge in today's wireless communication is how to serve the explosively increasing demand of multimedia service with the limited bandwidth. After the integrated evaluation of these future communication systems, it can be found that the orthogonal frequency division mulplexing technique would become the primary framework of those future wireless systems.In this thesis, we first took a look at the development of wireless communication systems. Some wireless communication techiniques and systems were intruduced briefly. Then we introduced the base concepts, advantagements and shortcomes of OFDM systems in detail. Then we completely represented the branch of OFDM technique: pre-equalization OFDM. After the review of the early research papers, we proposed the problems of pre-equalization OFDM systems that still existed in prompt. The main research direction and research contents were arised.The pre-equalization OFDM systems have some typical advantagement such as it can save the frequency resources and cut down the complexity of receiver. In the MC-CDMA systems, this technique can resolve the difficult of uplink channel estimation. The research direction of this thesis was to give the detailed analysis of pre-equalization OFDM systems and MC-CDMA systems.The early studies of pre-equalization were mainly based on simulations results, and the ideal conditions were supposed. In this thesis, we first described the system model of pre-equalization OFDM, and then we gave some bit error rate calculated expressions under the ideal condition. Two conventional pre-equalization schemes and a new one that we proposed were investigated. Further more, the system performance of nonideal condition were derived.In the third part of this thesis, some nonideal conditions were considered that would affect the performance of pre-equalization systems. The pre-equalization systems need to adopt TDD mode and calculate the pre-equalization factor using the channel...