This paper derives approximate outage probability (OP) expressions for uplink cell-free massive multiple-input-multiple-output (CF-mMIMO) systems with and without pilot contamination. The system's access points (APs) are considered to have imperfect channel state information (CSI). The signal-to-interference-plus-noise ratio (SINR) of the CF-mMIMO system is approximated via a Log-normal distribution using a two-step moment matching method. OP and ergodic rate expressions are derived with the help of the approximated Log-normal distribution. For the no-pilot contamination scenario, an exact expression is first derived using conditional expectations in terms of a multi-fold integral. Then, a novel dimension reduction method is used to approximate it by the sum of single-variable integrations. Both the approximations derived for the CF-mMIMO systems are also useful for single-cell collocated massive MIMO (mMIMO) systems and lead to closed-form expression. The derived expressions closely match the simulated numerical values for OP and ergodic rate.
@article{arxiv.2101.07737,
title = {Outage Probability Analysis of Uplink Cell-Free Massive MIMO Network with and without Pilot Contamination},
author = {Shashank Shekhar and Muralikrishnan Srinivasan and Sheetal Kalyani and Mohamed-Slim Alouini},
journal= {arXiv preprint arXiv:2101.07737},
year = {2023}
}
Comments
In this version, we have extended our analysis to multiple antenna AP and the scenario with and without pilot contamination