Distributed device discovery in ProSe environments

Reusing the frequency resources has long been a desirable practice in most licensed wireless networks. In future, frequency reuse will be enabled by advanced technologies like device-to-device (D2D) communication which will allow eNB-free data exchange between end devices. However, the first challenge for devices to establish D2D links will be to "discover" each other in a distributed manner. Even with the availability of network infrastructure, the distributed discovery will offload eNB's processing burden. However, due to the autonomous selection of resources for discovery, issues like half-duplexing and resource-collision will prevent efficient device discovery. In this paper, we present an autonomous method for discovery resources selection by modifying the standard frame structure. Our scheme introduces an additional randomness to the discovery process, which tends to mitigate half-duplexing and collision. The results have shown that the proposed scheme improves D2D discovery compared to conventional method, especially with low SINR and for larger DUE communication range.