Blind Estimation and Detection of Space Time Trellis Coded Transmission over the Rayleigh Fading MIMO Channel

Space-time trellis codes have been developed to prove the performance of wireless communication systems. The performance criteria for the fast Rayleigh fading channel model were developed in characterizing the space time codes with two quantities, the diversity advantage which describes the asymptotic error rate decrease as a function of the signal to noise ratio (SNR), and the coding advantage, which determines the vertical shift of the error performance curve. In this project, we propose the use of a conventional adaptive Viterbi algorithm to alternately detect the signal and further update the channel estimate. When a good channel estimate is obtained, it is adopted to setup the whole trellis. Signal decision and channel updating are all started from this channel estimate. Space timing trellis coding (STTC) is a unique technique that combines the use of multiple transmits antennas with channel coding. This scheme provides capacity benefits in fading channels, and helps in improving the data rate and reliability of wireless communication. STTC schemes have been primarily designed assuming perfect channel estimates to be available at the receiver. However, in practical wireless systems this is never the case. The noisy wireless channel precludes an exact characterization of channel coefficients. Even near perfect channel estimates can necessitate huge overhead in terms of processing or spectral efficiency. This practical concern motivates the study of the impact of channel estimation errors on the design and performance of STTC. The design criteria for STTC are validated in the absence of perfect channel estimates at the receiver. Analytical results are presented that model the performance of STTC systems in the presence of channel estimate errors. Training based channel estimation schemes are the most popular choice for STTC Systems. The amount of training however, increases with the number of transmit antennas used.