Dimension Compression Relaying for Slow Fading Channels Based on Hybrid Digital-Analog Source-Channel Coding

Hybrid digital-analog schemes for bandwidth compression/expansion have been proposed in source-channel coding to increase the robustness in terms of end-to-end distortion, and to combat threshold and leveling-off effects in the absence of transmitter channel state information. In the scenario that the dimension of the incoming codeword is compressed by the relay, we address a similar problem in a three-node half-duplex orthogonal relay network over slow fading channels, and propose two hybrid digital-analog relaying protocols that show significant improvements over digital-only (compress-and-forward and decode-and-forward) and analog-only (amplify-and- forward) schemes, in terms of the maximum achieved expected rate from source to destination.