Wei Wang
ABSTRACT
In multiuser MIMO-OFDM closed-loop system downlink, a proper scheduling algorithm can be used to extract the multi-user diversity by pouring more space-time-frequency (STF) resources to the user with better channel quality. For these systems, we aim to achieve further improvement without increasing the feedback overhead, and without sacrificing the performance gain the multiuser scheduling can provide. In this paper, a new space-frequency precoding scheme is proposed which makes better use of the additional diversity among different STF resources. In this scheme, the symbol streams at different STF resource are rotated before transmitting. These symbol streams should belong to the same user and have the same modulation and coding (MC) level. The rotation balances the signal to interference plus noise ratio (SINR) of each symbol stream, the average bit error rate (BER) performance is improved. With linear receiver, we proposed to use FFT basis as the rotation. Two cases occurred in space division multiple assess (SDMA) system are discussed. By the simulations in 3GPP long term evaluation (LTE) environment, the proposed scheme is proved to achieve lower BER and higher throughput than the existing systems.
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Digital Library
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- 3GPP TR 25.814 V2.0.0 (2006-6).Google Scholar
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Index Terms
- Space-frequency precoding scheme for multiuser MIMO-OFDM systems
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