Unlocking Collision-Free Communication: Self-Interference Cancellation in Random Access Multiuser MIMO

Abstract

This study suggests a method for MU-MIMO transmission's interference detection that makes use of periodic preamble signals in the frequency domain and the idea of full-duplex transmission when assuming idle antennas at the access point (AP). The proposed technique uses random access MU-MIMO, an asynchronous form of MU-MIMO, to provide collision detection (CD) of MU-MIMO. Asynchronous MU-MIMO causes numerous antennas in random access MU-MIMO to exist even when they are not being used for transmission. In order to prevent self-interference between AP antennas, full-duplex transmission allows idle antennas at the AP to receive preamble signals while the AP's transmit antennas send out the preamble signals.The interference can be identified by subtracting the brief preamble signal from the received signal following FFT processing, which is then multiplied by the predicted channel response. Additionally, to lessen the mutual coupling between the broadcast and receive antennas at the AP, we employ dual polarisation. The suggested approach may successfully identify collision from other user terminals (UTs) with OFDM signals when the interfering power from the interfering user terminal (IT) is greater than the noise power, as demonstrated by a computer simulation. Additionally, the potential usage of the suggested approach at the AP is described utilising the measurement data for the interfering power from IT at the AP and the intended user terminal (DT) in a real interior environment.