joint turbo equalization for relaying schemes over frequency-selective fading channels
We propose a single carrier joint frequency domain equalization and interference cancellation (FDE-IC) with diversity combining for different relaying schemes. We consider amplify-and-forward (AF) and ACK/NACK-aided decode-and-forward (DF) modes over multiple-input multiple-output (MIMO) frequency selective relay channels. During the first time slot, the source transmits to both the relay and destination. In the second slot, the relay transmits the signal packet to the destination in the case of AF mode, while in DF the data block is transmitted either by the relay or the source depending on the ACK/NACK feedback. By deriving an equivalent source-relay-destination ( S ? R ? D ) channel for the AF mode, we propose an integrated iterative minimum mean square error (MMSE)-FDE-IC-aided transmission combining scheme where reception over multiple slots is viewed as virtual antennas. We also derive the joint combining scheme in the case of ACK/NACK-aided DF. Block error rate (BLER) performance is evaluated for different system settings.
cooperative relaying multiple-antenna systems