Evaluation of turbo H-ARQ schemes for cooperative MIMO transmission

We compare the performance of different linear and non-linear receivers in the context of coded automatic retransmission schemes (type II hybrid ARQ) for cooperative transmission schemes as defined. Cooperative transmission can be seen as a "virtual" MIMO system, where the multiple transmit antennas are given by both the source and the relay terminal [R. Nabar et al.]. This relay may act as a regenerative or non-regenerative terminal, thus providing diversity/multiplexing gain. The evaluation of its actual performance requires the definition of distributed space time codes, forward error correction codes as well as an automatic repeat request protocols. Proposed schemes are evaluated in different conditions, both for linear and near-optimum (sphere decoder) receivers. Results show the benefits of coded cooperation over direct transmission in terms of increased throughput.