Optimal precoding for orthogonalized spatial multiplexing in closed-loop MIMO systems

In this paper, we propose a new precoding algorithm for orthogonalized spatial multiplexing (OSM) systems over flatfading multiple-input multiple-output (MIMO) channels. The OSM scheme was recently introduced for closed-loop MIMO systems which allows single symbol decodable maximum likelihood detection. To further improve the performance of the OSM system, we propose a new precoding method by maximizing the minimum Euclidean distance between constellation points in the effective channel. In order to efficiently identify the parameters of a precoder which maximizes the minimum distance, we introduce a partitioning approach. Through analysis, it is shown that one real value parameter and two bits are required for feedback information for precoding in 16-QAM systems. Simulation results demonstrate that our algorithm provides 9dB and 7.5dB gains at a bit error rate (BER) of 10-4 over the conventional OSM systems for 4-QAM and 16-QAM, respectively. We also confirm that the performance of th...

• Type: Journal
• Year: 2008
• Where: JSAC
• Authors: Young-Tae Kim, Heunchul Lee, Seokhwan Park, Inkyu Lee
• Keywords: Closed-loop Mimo Systems, JSAC 2008, Minimum Distance, Minimum Euclidean Distance