Space-time codes with full antenna diversity using weighted nonbinary repeat-accumulate codes

Like turbo codes, repeat-accumulate codes have remarkably good performance when r≥3, where r is the number of repetition times. We present space-time codes with full antenna diversity using "weighted" nonbinary repeat-accumulate codes. Compared with the space-time turbo codes of Y. Liu et al. (see IEEE J. Select. Areas Commun., vol.19, p.969-80, 2001) and of H. Su and E. Geraniotis (see ibid., vol.49, p.47-57, 2001), the main advantage of this new scheme is to construct space-time codes with full diversity for any m≤r and any length of frame without searching for interleavers, where m is the number of transmit antennas. These space-time codes have rate m/r and, so, have full rate when m=r. Furthermore, they have an efficient decoding based on the message passing algorithm.