Distributed Cooperative Data Relaying for Diversity in Impulse-Based UWB Ad-Hoc Networks

In this paper we develop and investigate two families of efficient distributed cooperative data relaying schemes that can be adopted to forward data in the impulse-based ultra wide band wireless ad-hoc network composed of a pair of source and destination and multiple parallel two-hop relays. The new schemes combine the mechanism of the medium access control and physical layers in a cooperative and distributed way to either select the best relay from multiple available ones for data forwarding or optimally combine the synchronized data forwarding of all participating relays, such as to improve the data transfer diversity. For distributed cooperative routing, we propose efficient protocols for use at all relays to perform an enhanced ultra wide band pulse sensing multiple access with the backoff periods deterministically and optimally mapped from associated instantaneous source-relay-destination route qualities, to ensure that only the best relay can firstly and successfully forward its received data to the destination; For distributed cooperative beamforming, we propose efficient protocols for use at all relays to take advantages of the widely spread and independently distributed multiple paths of the fading ultra wide band channels in the synchronized data forwarding combination, to create an optimally combined route for source-destination data transfer. Performance analysis and simulation studies show the effectiveness and efficiency of our proposed schemes.