Space-time trellis code design over rapid Rayleigh fading channels with channel estimation

In this paper, we provide a new, practical design criterion for space-time trellis codes over rapid fading channels with imperfect channel state information (CSI) at the receiver. This criterion exploits the statistical information of the channel estimates in code design. The minimum error performance can be achieved by optimally distributing the symbol-wise Euclidean distance based on the variances of the channel estimates. New codes designed with imperfect CSI are obtained using an iterative algorithm with reduced complexity. Simulation results show that in the presence of channel estimation errors, the codes designed based on our criterion assuming imperfect CSI have improved bit error probability performance compared with existing codes that were designed under the perfect CSI assumption. It is also shown that the effect of channel estimation on code design increases with the channel fade rate and the number of transmit antennas