Limited Feedback-based Block Diagonalization for the MIMO Broadcast Channel
Abstract
Block diagonalization is a linear precoding technique for the multiple antenna broadcast (downlink) channel that involves transmission of multiple data streams to each receiver such that no multi-user interference is experienced at any of the receivers. This low-complexity scheme operates only a few dB away from capacity but requires very accurate channel knowledge at the transmitter. We consider a limited feedback system where each receiver knows its channel perfectly, but the transmitter is only provided with a finite number of channel feedback bits from each receiver. Using a random quantization argument, we quantify the throughput loss due to imperfect channel knowledge as a function of the feedback level. The quality of channel knowledge must improve proportional to the SNR in order to prevent interference-limitations, and we show that scaling the number of feedback bits linearly with the system SNR is sufficient to maintain a bounded rate loss. Finally, we compare our quantization strategy to an analog feedback scheme and show the superiority of quantized feedback.
Cite
@article{arxiv.0711.3251,
title = {Limited Feedback-based Block Diagonalization for the MIMO Broadcast Channel},
author = {Niranjay Ravindran and Nihar Jindal},
journal= {arXiv preprint arXiv:0711.3251},
year = {2016}
}
Comments
20 pages, 4 figures, submitted to IEEE JSAC November 2007