P-Persistent stabilisation for wireless network diversity multiple access protocols

The Network Diversity Multiple Access (NDMA) protocols constitute an innovative way to resolve the packet collisions in wireless random access networks. However, unfavorable joint detection conditions at finite SNR can degrade their throughput performance. To mitigate this problem we propose a p-persistent stabilisation scheme to control the average number of colliding users. The optimum solution for the system parameters-i.e. the probability of false alarm and the parameter p-are given by a set of polynomial equations. A closed-form suboptimal solution, valid for large number of users and low SNR is demonstrated to be asymptotically bounded by the S-ALOHA characteristic. Further, with this new approach the throughput is optimized at the expense of a small delay degradation, and for traffic loads larger than a particular value the solution becomes traffic load independent. System parameters are analyzed by their analytical expressions and by simulations.