Collection of Correlated Information from Superimposed Multiple Chirp Signals

Wireless Sensor Networks (WSNs) based on Long-Range Wide Area Networks (LoRaWAN) are being used in various applications. In WSNs, in addition to periodic packet transmission, sensor nodes transmit packets when they detect an event. This action enables real-time information aggregation. When multiple sensor nodes detect an event at the same time, they send signals simultaneously, which may result in signal collisions at the receiver. This paper proposes a symbol detection method that allows information aggregation even when receiving superimposed chirp signals. Furthermore, this paper introduces an event source estimation method as a use case for collecting aggregate correlated information. Computer simulations show that the proposed method increases the probability of achieving the absolute source estimation error of 10 [deg.] by 11 points compared to conventional methods.