Asymmetric Quantizers Are Better at Low SNR
Abstract
We study the behavior of channel capacity when a one-bit quantizer is employed at the output of the discrete-time average-power-limited Gaussian channel. We focus on the low signal-to-noise ratio regime, where communication at very low spectral efficiencies takes place, as in Spread-Spectrum and Ultra-Wideband communications. It is well know that, in this regime, a symmetric one-bit quantizer reduces capacity by 2/pi, which translates to a power loss of approximately two decibels. Here we show that if an asymmetric one-bit quantizer is employed, and if asymmetric signal constellations are used, then these two decibels can be recovered in full.
Cite
@article{arxiv.1101.0970,
title = {Asymmetric Quantizers Are Better at Low SNR},
author = {Tobias Koch and Amos Lapidoth},
journal= {arXiv preprint arXiv:1101.0970},
year = {2011}
}
Comments
5 pages. To be presented at the 2011 IEEE International Symposium on Information Theory (ISIT) in Saint Petersburg, Russia. Replaced with version that will appear in the proceedings