Outage Probability of a Multi-User Cooperation Protocol in an Asychronous CDMA Cellular Uplink

In a recent paper, we proposed a multiuser space-time coded cooperative diversity protocol that operates in an asynchronous code-division multiple-access (CDMA) uplink under non-orthogonal channel assignment. The diversity combining of the relayed information was considered at the base station and the information-outage probability performance was investigated in a high-SNR regime. The goal of this paper is to extend those results and compare the performance of the proposed multi-user sharing protocol under diversity combining and code combining of the relayed transmissions at the base station and to examine the impact of using practical modulation techniques on the information-outage probability performance of the proposed multi-user cooperation protocol. We see that the performance loss due to modulation constraints and the use of diversity combining instead of code combining is relatively small.