Downlink SDMA with Limited Feedback in Interference-Limited Wireless Networks
Marios Kountouris, Jeffrey G. Andrews

TL;DR
This paper analyzes the performance of SDMA with limited feedback in interference-limited wireless networks, revealing that limited feedback significantly degrades capacity and that single-stream transmission is often optimal.
Contribution
It provides closed-form expressions for key performance metrics and demonstrates the necessity of increasing feedback with antennas and SINR to maintain multiplexing gains.
Findings
Per-user feedback rate must increase linearly with antennas and SINR for full multiplexing.
Single-stream transmission is optimal in most practical interference-limited scenarios.
SDMA is generally not advisable for interference-limited wireless networks.
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…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
