Performance analysis of framed ALOHA systems with diversity transmission and erasure

The performance of a framed ALOHA system that employs diversity transmission techniques in an erasable multiple access radio channel is investigated. Two diversity transmission schemes, as well as a modified version of them, differentiated by the underlying channel sampling procedure, i.e., sampling with replacement and sampling without replacement, are presented. The modified schemes use the same channel sampling algorithm as their predecessors, but diversity transmission applies only to a backlogged user. For all the cases considered, an exact combinatorial analysis has been developed to evaluate the system throughput and the activity factor versus throughput characteristics. Pros and cons of using diversity transmission and effects of erasure on the performance are discussed