Blind collision resolution using retransmission diversity under quasi-static fading channels

Abstract

Wireless multiple access protocols with retransmission diversity resolve packet collisions through source separation techniques. The number of retransmissions to achieve the necessary diversity level equals the collision multiplicity, whose proper detection is essential for good performance. The so-named network-assisted diversity multiple access (NDMA) resolves the collisions under quasi-static fading, but it is a non-blind approach. Moreover, the blind version of NDMA (BNDMA) requires tight transmitter phase control and static channels. As another blind method, NDMA with independent component analysis (ICA-NDMA) performs under quasi-static channels, but its multiplicity detection technique suffers at low SNRs. In this paper, efficient collision resolution is achieved by employing a new multiplicity detection technique for ICA-NDMA, where both theoretical and experimental results are presented. © Springer-Verlag 2004.