DocumentCode :
1525503
Title :
Downlink SDMA with Limited Feedback in Interference-Limited Wireless Networks
Author :
Kountouris, Marios ; Andrews, Jeffrey G.
Author_Institution :
Department of Telecommunications, SUPELEC (Ecole Superieure d´´Electricite), Gif-sur-Yvette, France
Volume :
11
Issue :
8
fYear :
2012
fDate :
8/1/2012 12:00:00 AM
Firstpage :
2730
Lastpage :
2741
Abstract :
The tremendous capacity gains promised by space division multiple access (SDMA) depend critically on the accuracy of the transmit channel state information. In the broadcast channel, even without any network interference, it is known that such gains collapse due to interstream interference if the feedback is delayed or low rate. In this paper, we investigate SDMA in the presence of interference from many other simultaneously active transmitters distributed randomly over the network. In particular we consider zero-forcing beamforming in a decentralized (ad hoc) network where each receiver provides feedback to its respective transmitter. We derive closed-form expressions for the outage probability, network throughput, transmission capacity, and average achievable rate and go on to quantify the degradation in network performance due to residual self-interference as a function of key system parameters. One particular finding is that as in the classical broadcast channel, the per-user feedback rate must increase linearly with the number of transmit antennas and SINR (in dB) for the full multiplexing gains to be preserved with limited feedback. We derive the throughput-maximizing number of streams, establishing that single-stream transmission is optimal in most practically relevant settings. In short, SDMA does not appear to be a prudent design choice for interference-limited wireless networks.
Keywords :
Ad hoc networks; Interference; Multiaccess communication; Receivers; Signal to noise ratio; Throughput; Transmitters; MIMO communication; ad hoc networks; finite rate feedback; poisson point process; space-division multiple access (SDMA);
fLanguage :
English
Journal_Title :
Wireless Communications, IEEE Transactions on
Publisher :
ieee
ISSN :
1536-1276
Type :
jour
DOI :
10.1109/TWC.2012.051712.110357
Filename :
6205588
Link To Document :
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