Implementation Strategies for High-Performance Multiuser MIMO Precoders

Abstract

The multiuser MIMO environment enables the communication between a base-station and multiple users with several antennas. In such a scenario, the use of precoding techniques is required in order to detect the signal at the users' terminals without any cooperation between them. This contribution presents various designs and hardware implementations of a high-capacity precoder based on vector perturbation. To this aim, three tree-search techniques and their associated user-ordering schemes are investigated in this chapter: the well-known K-Best precoder, the fixed-complexity Fixed Sphere Encoder (FSE), and the variable complexity Single Best-Node Expansion (SBE). All of the aforementioned techniques aim at finding the most suitable perturbation vector within an infinite lattice without the high computational complexity of an exhaustive search.