A position detection system (10) includes receivers (20a to 20g) constituting a radio mesh network, and a gateway device (30). Each of the receivers (20a to 20g) includes a receiving unit (22), a sending unit (23), and a control unit (24). When the receiving unit (22) in each of the receivers (20a to 20f) receives the beacon, the control unit (24) generates first reception information containing information indicating signal strength of the received beacon and identification information of the relevant receiver, and sends the first reception information from the sending unit (23). When the receiving unit (22) receives second reception information, the control unit (24) sends the second reception information. When receiving the second reception information generated by the other receiver, the receiver (20g) connected to the gateway device (30) sends the received second reception information to the server device (34) through the gateway device (30).