Focusing on the near-far influence problem in the multiple-antenna downlink
the performance of spatial multiplexing(SM)in the distributed multiple-antenna system is studied. It is shown that the distributed multiple-antenna system can lead to effective reduction of the near-far influence. Thereby
an adaptive transmission scheme is proposed. This scheme flexibly switches the transmission strategy according to the locations of the users relating to the antenna ports. SM joint transmission is chosen to eliminate the inter-user interference when the users are far from the antenna ports
while the transmit selection(TS)is chosen to reduce the feedback load and the complexity when users come close to the antenna ports. Simulation results show that by rightly setting the adaptive switching threshold
the proposed scheme can considerably reduce the feedback load and the processing complexity in 40% of all the channel realizations with only 7% loss of system capacity compared to the SM joint transmission.
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references
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