The Effect of Imperfect Channel Estimation on the Performance of Layered Space Time Receivers

The Bell Labs layered space-time (V-BLAST) algorithm is a promising multiple-input multiple-output (MIMO) transmission scheme. It attempts to utilize the high capacity of a MIMO system while maintaining low complexity. While no channel knowledge is required at the transmitter, accurate estimates of the channel are necessary at the receiver. The objective of this paper is to simulate numerically the wireless channel and the V-BLAST architecture to compare the performance of zero forcing (ZF) and a mean squared error (MMSE) receivers using linear nulling and symbol cancellation under imperfect channel state information (CSI). The simulation will compute the bit error rate for different values of SNR in a flat fading channel under imperfect channel estimation. The transmitted symbols will be modulated using a QPSK constellation. The results will be compared to those simulated using pilot estimation.