Towards optimal space-time coding

We study the effect of number of receive antennas on the design criteria of space-time codes. We present an upper bound on the probability of error that captures the dependence of code design on the number of receive antennas. Using this bound, we analyze the optimality trends of a class of linear space-time block codes. Numerical results demonstrate the utility of the bound in characterizing the relative performance ordering of different space-time codes. We further prevent a simple approach for constructing space-time trellis codes that exhibit near-optimal performance with different levels of receive diversity.