The Multiplexing Gain of the Network MIMO Channel With Distributed CSI

摘要: In this work, we discuss the joint precoding with finite rate feedback in so-called Network MIMO where TXs share knowledge of data symbols to be transmitted. We introduce a distributed channel state information (DCSI) configuration each TX has its own local estimate overall multi-user matrix and must make decision solely based on available CSI. refer as DCSI-MIMO problem precoding. extend DCSI setting work from Jindal for conventional Broadcast Channel (BC) which multiplexing gain (MG) achieved by Zero Forcing (ZF) was derived function scaling logarithm Signal-to-Noise Ratio (SNR) number quantizing bits. Particularly, show seemingly pessimistic result that MG at user is limited worst CSI across all users TXs. This contrast BC one dependent quality estimation his feedback. Consequently, provide schemes improving MG, two-user cases novel precoder achieves best accuracy instead lowest ZF. also advocate use hierarchical CSI, considerable gains are possible. Finally, previous analysis derive optimal allocation bits various under constraint size aggregate network.