Spread Unsourced Random Access With an Iterative MIMO Receiver

Abstract

This work is dedicated to the unsourced random access (URA) with multiple-antenna receiver. We utilize a preamble-payload packet format where the preamble, selected from a pool shared between all active users, serves as a temporary activity detection identifier. The payload carries the main portion of the message data which is encoded for error correction, permuted, and scrambled. The compressed-sensing (CS) preamble receiver that estimates the active preambles and the respective user channels is followed by a payload receiver which performs several iterations of data and channel estimation and parallel interference cancellation. Our numerical and analytic results demonstrate that the presented system outperforms the related work in terms of the achievable numbers of active users and signal-to-noise ratios (SNR)s supported by the system.