Mobile radio slotted ALOHA with capture, diversity and retransmission control in the presence of shadowing

In this paper, the capture performance of a random access scheme in the presence of Rayleigh fading, shadowing and diversity is studied. The conditional throughput Cn, i.e., the average number of packets which are correctly received per slot, given the number of colliding packets, n, is computed, as well as its limit as n ! 1. Some different diversity schemes are compared. Also, retransmission control is considered as a means to enhance the system performance. The stability of the controlled system is directly proved. Finally, the effect of long-term attenuations on the system performance and stability is discussed.