Performance enhancement of mobile radio slotted ALOHA networks using retransmission combining

The throughput of slotted ALOHA in a mobile radio channel is degraded due to signal fading and a packet may not be received successfully even when there is no collision. A retransmission combining technique is introduced in which a packet received with errors is not discarded; instead, it is stored and combined with the packet(s) received in the following retransmission(s). The throughput performance of slotted ALOHA with retransmission combining is studied, and an improvement in performance is observed. A comparison with space diversity is made