On the construction of layered space-time coded modulation (STCM) codes employing MTCM code design techniques

The field of space-time coded modulation (STCM) has recently attracted interest as a means of improving link reliability in mobile environments. It has been shown that these space-time multiple-antenna systems provide very high capacity when compared to single antenna systems in a Rayleigh fading environment. Specifically for the forward link, space-time coded transmit diversity should be incorporated into the wireless communication system in order to take full advantage of the combined space- (multiple-transmit antennas) and time- (forward error correction coding) diversity scheme. In this paper, we adopt an heuristic approach to the design and evaluation of diagonally layered STCM schemes by utilising classical multiple-trellis coded-modulation (MTCM) techniques. We focus mainly on the construction of simple 4-state diagonally layered space-time convolutionally coded systems. The designed STCM systems will be used in a comparative performance investigation with the originally proposed STCM codes. Computer simulations are used to evaluate the performance of the code designs on flat Rayleigh fading channels.