Multicarrier SDMA system with reduced intra-user cross-correlations
The ability of the basestation to separate several users spatially depends on the pair wise cross-correlations between the channel matrices of the users. In this paper we propose an improved null steering downlink MIMO-OFDM system that reduces the intra-user correlations resulting in significant enhancement in system performance. In this system, several basestation multi-antenna arrays are distributed in a given area. Each array is communicating with the basestation via optical fiber links. All signal processing is performed at the basestation. Multi-antenna users are spatially separated such that in each tone of the OFDM symbol only a certain number of users (out of the total number of users) are selected. The selection is based on an algorithm that reduces the pair-wise intra-user correlations. The channel matrix of each user is assumed correlated (generated based on certain angular spectrum and random angular spread) and Ricean distributed (each array has a random K-factor). Several data symbols can be spatially multiplexed to each user over each OFDM tone with high reliability and with very good total system capacity.
|Keywords||Distributed antennas, MIMO, OFDM, SDMA|
|Conference||5th International Workshop on Multi-Carrier Spread-Spectrum, MC-SS 2005|
Dawod, N.H. (Nadem H.), Hafez, R, & Marsland, I. (2006). Multicarrier SDMA system with reduced intra-user cross-correlations. Presented at the 5th International Workshop on Multi-Carrier Spread-Spectrum, MC-SS 2005.