On the Design of Turbo Packet Combining Schemes for Relay-Assisted Systems over Multi-Antenna Broadband Channels

Abstract

This paper focuses on turbo packet combining strategies for multi-relay-assisted systems operating over multiple-input-multiple-output (MIMO) broadband channel. We propose a frequency domain minimum mean square error (MMSE)-based turbo packet combining scheme where all slots received signals and their corresponding channel frequency responses (CFR)s are used to decode the data packet. We also provide an efficient recursive implementation way for the proposed scheme, and show that both its computational complexity and memory requirements are quite insensitive to the number of relays in the system. For the special case of cooperative automatic repeat request (ARQ) systems, we introduce an adaptive packet combining algorithm that enable to reduce the receiver implementation cost. Block error rate (BLER) performance are provided to demonstrate the gains offered by the proposed combining scheme over the conventional soft information-based combining.