Mimo-ofdm Synchronization Interference Analysis And Implementation

The ever-increasing demand for high quality connection brings forward communication research continuously. Up to now, broadband and mobility had become two major concerns in wireless system study. 3G, WLAN and WiMAX, which have developed on their own, will eventually merge as one single standard. From a physical layer aspect, those techniques feature high frequency and power efficiency, and are able to adapt to changing environments and services, will win in the long run. Among them, MMO-OFDM, which inherits both advantages of MMO(Multiple Input Multiple Output) and OFDM(Orthogonal Frequency Division Multiplexing), is a most promising candidate for next generation wireless systems.This thesis focuses on synchronization techniques for MMO-OFDM system in packet mode transmission, as well as MMO channel modeling in the circumstance of broadband and high mobility environment.A well understanding of channel property is important for proper receiver design. However, to the best of author's knowledge, there is little paper on MMO channel modeling for broadband and highly mobile situation. In this thesis, both discrete-time and angular domain expressions of the channel coefficients are derived. Further, the coefficients' statistical distributions, as well as time-space correlation, are studied. Some interesting results are found which differ from traditional textbook.Due to sensitivity of synchronization error, OFDM suffers great performance loss when the receiving signal is not well synchronized. Based on theoretical analysis of synchronization errors on the performance of OFDM systems, normal synchronization algorithms for MMO-OFDM system under burst mode transmission, including frame detection, coarse timing, fractional frequency offset estimation, integral frequency offset estimation, fine timing, sampling frequency error correction and residual phase tracking are designed and simulated in sequence. Most of the algorithms are derived from SISO(Single Input Single Output) situation and modified to meet MMO specification.