Cell-Free System's Performance under RF Mismatch

The need to increase and to uniformize transmission rates for all users of multi-user communications revived the interest in configurations in which base station antennas are distributed in space. In particular, cell-free system, where space is not divided into limited regions, and all access points serve all users, have received special attention. Although its weak channel hardening, this systems have shown to be advantageous in several ways. In this work, we obtained an analytical expression for the signal-to-interference-plus-noise-ratio in systems cell-free affected by an effect called radio frequency mismatch. The effectiveness of this expression was evaluated based on the analysis of achievable rates under various conditions. Since there was a displacement between the Cumulative Distribution Function curves obtained with the analytical expression and the channel realizations, the rates remained in the same order of magnitude, indicating that it can be used to predict system performance with some precision.