研究目的

To propose a simple quantization scheme for adjusting separately the amplitudes and phases of signals in a codebook-based Transmit Beamforming (TBF) scheme, valid for both desired signal power maximization and co-channel interference mitigation, without requiring an exhaustive search to find the optimal TBF vector.

研究成果

The proposed simplified TBF codebook design, where both channel amplitudes and phases are quantized and reported separately, provides a good alternative to improve data rates in FDD mobile networks. For egoistic TBF, most of the available performance gain is achieved with a relatively low number of feedback bits. In case of altruistic TBF, the interference suppression performance increases with the number of feedback bits with no saturation, provided that feedback bits are properly shared between the quantizations of channel amplitude and phase parts of channel gains.

研究不足

The study is limited to a 2 Tx-1 Rx antenna scenario with independent block Rayleigh fading. The performance saturation is observed for egoistic TBF when the feedback resolution reaches a certain level, and for altruistic TBF, performance increases with the number of feedback bits without saturation, provided that feedback bits are properly shared between the quantizations of channel amplitude and phase parts of channel gains.