A Novel Detection Algorithm for Random Multiple Access Based on Physical-Layer Network Coding

In this paper, we propose a novel detection algorithm for random multiple access, which combines slot based decoding and frame based decoding to recover users' messages. For the slot based decoding, we exploit a linear physical-layer network coding (LPNC) algorithm to decode the linear combinations of collided packets at each slot. By designing the coefficient matrix of linear combinations, we have the decoded linear combinations independent of each other in each slot. At frame level, we have equations constructed by linear combinations from all slots within one frame, and we adopt Gaussian elimination aided successive interference cancellation (GE-SIC) decoding method to recover users' messages. We show that our LPNC algorithm can increase the number of linear combinations per slot by minimizing the decoding error probability. In addition, we demonstrate that the proposed scheme can significantly improve the system performance in terms of throughput and packet loss rate.