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This paper presents the achievable capacity expressions with analytical closed forms of spatial multiplexing transmission (SMT) and single antenna transmission (SAT) for multicell downlink distributed antenna systems (DAS). Considering that SMT and SAT yield high transmission gains of the center and the edge of the cell, respectively, we also propose switching algorithms depending on a user location. The transmission scheme decides a favorable transmission technique between SMT and SAT through instantaneous or ergodic capacity comparison. Simulation results show that the analytical closed forms well match to the empirical expressions. Furthermore, the proposed transmission schemes are superior to SMT and SAT.

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In this paper, we investigate the effect of inaccurate channel estimation on the bit error rate (BER) performance of the convolutionally coded MJMO-OFDM systems with multilevel quadrature amplitude modulation (M-QAM, M= 16, 64) and diferent diversity orders, particularly in spatially correlated fading channels. It is shown that, in a highly correlated fading channel, the 16-QAM system employing increased diversity order is remarkably more sensitive to the channel estimation errors than the same system but with the 64-QAM On the other hand, when thefading correlation ofthe channel is low, the 16-QAM system with antenna diversity appears to become more robust to the channel estimation errors than the 64-QAM system with the same antenna diversity in terms ofthe BER performance.