Asynchronous Blind Network-Assisted Diversity 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 collided signals. The proposed scheme works independently of the relative alignment of the packets, so it can also resolve synchronous collisions. The decoding complexity does not scale with the packet size and thus does not burden the receiver. In the blocking mode, the algorithm achieves high throughput and low queuing delay similar to synchronous network division multiple access (NDMA) protocols. In the non-blocking mode, there is longer queuing delay of the packets before transmission, but the throughput is still high due to faster accumulation of the buffered packets at the transmitters.