Reconfigurable MIMO transceivers for next-generation wireless systems

Next-generation wireless systems are expected to optimize performance by providing adaptivity to varying network conditions. In this paper, we present recent advances in multiple input, multiple output (MIMO) networks that are designed to make reconfigurable operation possible in the context of a Universal Mobile Telecommunications System (UMTS*) network environment. We focus on the problem of robust/reconfigurable operation with respect to channel correlation, which is known to have a significant effect on the performance of MIMO links. Our approach to bringing such robustness to space-time encoded systems is to introduce linear precoding, which is designed to account for the effects of antenna correlation. After verifying the success of this approach in improving the robustness of MIMO links, we evaluate its benefits at the system level. We introduce link-to-system interface metrics to ensure realistic evaluation of system-level performance, and we evaluate the average-system-throughput and number-of-satisfied-users performance metrics. Finally, we describe our simulations, which demonstrate the performance improvements that can be achieved by applying reconfigurable techniques rather than conventional ones. (c) 2005 Lucent Technologies Inc.