Linear Precoding for Multi-Antenna CDMA over Multipath ISI Channels
نویسندگان
چکیده
We consider the performance of linear transmitter precoding techniques for the downlink of multiinput single output (MISO) DS-CDMA systems over multipath channels with and without intersymbol interference (ISI). Our receivers are constrained to simple match filters while the transmitter is assumed to have complete or partial channel state information (CSI). Our contribution in this paper is the design of linear interference cancelling precoders which simultaneously exploit the available multipath diversity to improve the signal to interference noise ratio (SINR) performance. Precoders are designed such that the resulting decision statistics at the receivers closely mimic those due to maximum ratio weighting which maximizes the effective SINR. Simulation results indicate that linear precoders designed for channels without ISI achieve full diversity gain while completely suppressing multiuser interference at the cost of a SINR loss in the performance. Those designed for ISI channels achieve full diversity gain when there are a small number of distinct paths from any transmit antenna to the single receive antenna of each decentralized receiver.
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