Channel Estimation and Data Decoding Analysis of Massive MIMO with 1-Bit ADCs

We present an analytical framework for the channel estimation and the data decoding in massive multiple-input multiple-output uplink systems with 1-bit analog-to-digital converters (ADCs). First, we provide a closed-form expression of the mean squared error of the channel estimation for a general class of linear estimators. In addition, we propose a novel linear estimator with significantly enhanced performance compared with existing estimators with the same structure. For the data decoding, we provide closed-form expressions of the expected value and the variance of the estimated symbols when maximum ratio combining is adopted, which can be exploited to efficiently implement maximum likelihood decoding and, potentially, to design the set of transmit symbols. Comprehensive numerical results are presented to study the performance of the channel estimation and the data decoding with 1-bit ADCs with respect to the signal-to-noise ratio (SNR), the number of user equipments, and the pilot length. The proposed analysis highlights a fundamental SNR trade-off, according to which operating at the right noise level significantly enhances the system performance.