Blind channel estimation for MIMO OFDM communication systems

CHEN XI

Publication

Blind channel estimation for MIMO OFDM communication systems

CHEN XI

Abstract

The main contribution of this thesis is the development of blind channel estimation and source separation algorithms for MIMO-OFDM systems. In the 1st proposed channel estimation algorithm, we study the inherent structure of autocorrelation matrices of the system output and construct a new criterion function, minimizing which leads to a close form solution of the channel matrices. The second algorithm is based on the assistance of a non-redundant linear precoder, which brings in cross-correlations between the signals transmitted on different subcarriers. For the third one, we exploit the spectra correlation of the system output. It is shown that when the source signals have distinct spectra correlation, the problem of the ambiguity matrix in many of the existing blind channel estimation algorithm can be avoided. The blind source separation algorithm proposed in this thesis is a geometric based non-iterative algorithm based on the assumption that the source signal has finite alphabet.