Cooperative ARQ for distributed space-time coding: The diversity-multiplexing-delay tradeoff

The throughput and the tradeoff between the diversity, multiplexing and the delay constraint of cooperative automatic retransmission request (ARQ) are investigated for distributed space-time coding (DSTC). According to the analysis, the maximum operational throughput turns out to be a piecewise linear curve with respect to the signal to noise ratio in decibel. In addition, the multiplexing gain divided by the average transmission times, referred to as the effective multiplexing gain, appears to be a better performance measure for delay-limited cooperative ARQ schemes. The tradeoff between the diversity and effective multiplexing gains is characterized for cooperative ARQ using DSTC in slow and fast fading channels, respectively.