This work extends the concept of channel hardening to multi-antenna systems that are aided by intelligent reflecting surfaces (IRSs). For fading links between a multi-antenna transmitter and a single-antenna receiver, we derive an accurate approximation for the distribution of the input-output mutual information when the number of reflecting elements grows large. The asymptotic results demonstrate that by increasing the number of elements on the IRS, the end-to-end channel hardens as long as the physical dimensions of the IRS grow as well. The growth rate however need not to be of a specific order and can be significantly sub-linear. The validity of the analytical result is confirmed by numerical experiments.
@article{arxiv.2205.15642,
title = {How Should IRSs Scale to Harden Multi-Antenna Channels?},
author = {Ali Bereyhi and Saba Asaad and Chongjun Ouyang and Ralf R. Müller and Rafael F. Schaefer and H. Vincent Poor},
journal= {arXiv preprint arXiv:2205.15642},
year = {2022}
}
Comments
Accepted for presentation at 2022 IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM ) in Trondheim, Norway; 5 pages and 2 figures. arXiv admin note: text overlap with arXiv:2203.11592