Transmitter channel state information and repetition protocols in block fading channels

In this paper, we study the throughput performance of repetition protocols over block fading channels. We show that, by allocating different power to different retransmissions, the throughput can be improved, especially at high SNR. We also show that, if one bit of available feedback is used to signal decoding failure and channel condition, then great throughput improvements are possible, especially at low SNR. We conclude, by proposing a simple repetition protocol with a single retransmission that improves the throughput with respect to the incremental redundancy protocol without TXCSI and with respect to the repetition protocol with TXCSI.