Research On The Performance Of Ovtdm And Turbo-Ovtdm Technology Applicated In Multi-Carrier System

Mobile communication has become an indispensable means of communication in modern human society, and the increasing demands put forward higher requirements to the system. Reliability and efficiency are two targets to evaluate the performance of the system. Professor Li has put forward a transmission mode based on the principle of overlapped multiplexing, as an innovative technology oriented to future mobile communication.The core idea is through the overlap between the signals to improve the spectrum efficiency and bring the potential performance gain.This article is based on the principle of overlapped multiplexing and make further research on OvCDM and OvTDM technology:The first chapter introduces the research background and summarizes the development of mobile communication system and the principle of overlapped multiplexing, then introduces the main arrangement of this article;The second chapter is based on the overlapped code division multiplexing technology.First introduce the basic model,then discuss the performance of parallel transmission of orthogonal multiplexing OvCDM system scheme. Secondly, for finding a OvCDM coding matrix of high spectrum efficiency, focus on the OvCDM coding matrix’s properties and performance.The third chapter is based on the overlapped time division multiplexing technology. First introduce the basic model, then construct a Pure-OvTDM and Shift-OvTDM serial cascading system for higher spectral efficiency. Search the optimal combination mode when Pure-OvTDM and Shift-OvTDM has different portion of the spectrum efficiency. Further, introduce the Turbo structure, and recursive Turbo structure to the system, and validate their excellent performance. Then propose a coded serial cascading OvTDM system with the convolutional code to further improve the performance. Finally, have research on the serial cascading OvTDM system of RRC wave.The fourth chapter combined the overlapped time division multiplexing technology with time-frequency LA codes in multicarrier system.First present a time-frequency LA code and analyze the aperiodic autocorrelation and cross-correlation properties.Combined with the integer-chip-shift OvTDM, there is no interference between the usersin a single cell. Then a new scheme of multi-cell networking based on time-frequency LA code is proposed and analyzed.