| In this paper, we consider adaptive modulation (AM) using
differential space-time block codes (DSTBC) in the presence of
Rayleigh fading channel. A MIMO system, DSTBC can be simplified to
be a multiple SISO (scalar) system with a diversity gain. A
near-instantaneous signal-to-noise (SNR) ratio at the DSTBC receiver
is used as a channel quality estimate. Using the channel quality,
the system is able to choose a set of SNR thresholds that maximize
throughput and keeps the target bit-error-rate (BER) for a given
average transmitted SNR. |