New QPSK space-time trellis codes

It has been shown that the design criteria for space-time trellis codes over quasi-static Rayleigh fading channels are the rank criterion and the determinant criterion. Recently, a new design criterion that maximizes only the trace of the distance matrices has been proposed for systems with a large product of the numbers of transmit and receive antennas. These codes are superior when the number of receive antennas is 4 or more. In this paper, the two design criteria are combined so that the codes are good or robust whatever the number of receive antennas is. New QPSK codes that optimize the trace/determinant pair and achieve the full rank are presented. These codes outperform other previously known codes whether there are two receive antennas or more.