Random Access Based Blind Relay Selection in Large-Scale Relay Networks

A random access based blind relay selection (RAB RS) scheme is proposed. Due to the size and the blind characteristic of the large-scale relay service networks, collecting the real-time status of the relays is a very difficult task. To address this problem, the proposed scheme enables the user to randomly select a relay through slotted ALOHA, without requiring any relay information. In addition, the high collision probability of the selection phase can be reduced by introducing an available relay region to adaptively decrease the number of the available relays. This geographical region consists of all the relays that satisfy the required rate of the user at the target outage probability. Compared with the upper bound that requires the complete relay information, the proposed RABRS scheme is implemented in a blind manner while maintaining almost optimal performance.