Asynchronous Blind Network Division Multiple Access

Abstract

We present a blind collision resolution algorithm in slow fading channels based on retransmission diversity. The algorithm neither assumes packet nor symbol synchronization of the different users and it does not demand estimates of the arrival times of the colliding signals. The proposed scheme works independently of the relative alignment of the packets, and so it can also resolve synchronous collisions. The decoding complexity does not scale with the packet size and thus does not burden the receiver. Having forgone synchronization, the penalty paid is a longer queueing delay of data at the transmitters. Still the algorithm achieves high throughputs similar to synchronous network division multiple access (NDMA) protocols.