On the design of discovery patterns for half-duplex TDD nodes operating in frame-based systems

Future telecommunication systems need to support a discovery function, enabling all network nodes to discover each other directly over the air. In addition to discovery in traditional access point-to-user equipment (AP2UE) links, there is a need to support also other link types, such as device-to-device (D2D) communication and wireless backhauling. In this paper, we provide a design for discovery patterns and groups of patterns applicable to half-duplex time division duplexing (TDD) nodes operating in a frame based system. The proposed scheme allows an easy design of discovery patterns, which can be used for comprehensive bi-directional communication where all nodes are able to listen to each other. Proposed approach provides also an upper limit for the discovery time with an assumption that discovery signal is received correctly at the receiving node. We also support network topologies containing network elements of different hierarchies which require mono-directional discovery function among network nodes, e.g. from higher towards lower hierarchy levels.