Superimposed Pilot ODMA Transmission for Massive MIMO Unsourced Random Access

This letter proposes a novel superimposed pilot (SP) on-off division multiple access (ODMA) transmission scheme for massive multiple-input multiple-output (MIMO) unsourced random access (URA). In this scheme, the SP conveys on-off pattern information by sharing the transmission frame with data load, utilizing the super sparse property of ODMA to minimize multi-user interference. On the receiver side, an energy detection aided non-Bayesian superimposed pilot detection (NB-SPD) receiver is designed to recover the messages transmitted by the active users. Furthermore, a low complexity successive interference cancellation (SIC) is used to enhance the performance. Numerical results demonstrate superior performance compared to state-of-the-art approaches.