Advances in analog-to-digital converter (ADC) technology have opened up the possibility to directly digitize wideband radio frequency (RF) signals, avoiding the need for analog down-conversion. In this work, we consider an orthogonal frequency-division multiplexing (OFDM)-based massive multi-user (MU) multiple-input multiple-output (MIMO) uplink system that relies on direct RF-sampling at the base station and digitizes the received RF signals with 1-bit ADCs. Using Bussgang's theorem, we provide an analytical expression for the error-vector magnitude (EVM) achieved by digital down-conversion and zero-forcing combining. Our results demonstrate that direct RF-sampling 1-bit ADCs enables low EVM and supports high-order constellations in the massive MU-MIMO-OFDM uplink.
@article{arxiv.1907.07091,
title = {Massive MU-MIMO-OFDM Uplink with Direct RF-Sampling and 1-Bit ADCs},
author = {Sven Jacobsson and Lise Aabel and Mikael Coldrey and Ibrahim Can Sezgin and Christian Fager and Giuseppe Durisi and Christoph Studer},
journal= {arXiv preprint arXiv:1907.07091},
year = {2019}
}