Signal-Level Turbo Packet Combining for Multi-Rate Relay-Assisted Systems over Multi-Antenna Broadband Channels

This paper proposes a signal-level turbo packet combining strategy for multi-antenna multi-rate relay-assisted systems operating over broadband channel. We derive a fixed rate equivalent multi-antenna system communication model where the multi-rate multi-node received signals can be viewed as direct retransmissions from a virtual node with a fixed transmission rate. Using virtual antenna concept, we introduce a frequency domain turbo packet combiner inspired by minimum mean square (MMSE) criterion. Block error rate (BLER) performance are provided to demonstrate the gains offered by the proposed combining scheme over the conventional soft information-based combining.