Cooperative wireless medium access with multi-beam adaptive arrays

A cooperation-based medium access protocol for wireless networks was recently proposed, that through its ability to resolve collisions can achieve high throughput. In this paper, we propose a new scheme for collision resolution that combines the idea of cooperative retransmissions and use of multi-beam adaptive arrays (MBAA) at the base station (BS). In the event of multiple users accessing the channel in the same slot, the MBAA will form a number of beams, each of which will capture packets coming from different directions. Single-packet beams will yield the corresponding packets, while multiple-packet beams will invoke collision resolution via cooperative relaying. We show that the proposed approach can achieve significant throughput gains as it reduces the effective collision order and the collision resolution period as compared to the cooperative approach without MBAA. The improvement is obtained at the expense of additional hardware cost at the BS.