WLC35-6: Relay-Assisted Spatial Multiplexing in Wireless Fixed Relay Networks

Fixed relays are expected to be a part of future infrastructure-based wireless networks. Besides coverage extension, such relays can form advanced architectures due to the flexibility in their power expenditure and physical size. This paper explores the potential benefits of multi-antenna relays for spatial multiplexing of independent data sources sending data to a common multi-antenna destination such as a base station or an access point. Overall, the system resembles a horizontally coded layered space-time architecture. In particular, we consider zero forcing decision feedback (ZF-DF) type MIMO receivers and study their outage performance under various (non-selective and selective) digital relaying protocols. For diversity relaying protocol, we propose two schemes, Joint ZF-DF and Parallel ZF-DF, for joint processing (combining and decoding) of the direct user signals and the signal from the relay. We show that with the proposed selective diversity relaying protocols and joint ZF-DF processing, the outage probability of the system can be decreased significantly.