Performance analysis of analog network coding ALOHA systems using tagged user approach

In this paper, we analyze the analog network coding ALOHA (ANC-ALOHA) system using the tagged user approach (TUA). ANC-ALOHA is the first random access scheme to apply analog network coding to slotted ALOHA for the throughput enhancement of a two-way relay channel. We analyze the performance of an ANC-ALOHA system with propagation delay, a finite population and finite buffer capacity. This model of the system is more practical than one with infinite population and a single buffer. Under the assumption that the statistical behavior of all users is identical, the TUA can solve a complicated buffered system without computational complexity concerns arising from a large state space. We design a message service time distribution (MSTD) by taking into account the service patterns of ANC-ALOHA. We then apply the derived MSTD to conventional queueing theory and obtain performance measures such as channel throughput, mean queue length, and mean message response time. Numerical results confirm the efficient performance and stability of ANC-ALOHA. We also verify the accuracy of our analysis through extensive simulations.