2021 年 12 巻 4 号 p. 726-737
An Internet of Things (IoT) employing resource-restricted (e.g., battery-limited) IoT devices at high densities will require an effective multiplexing protocol that can be implemented with low energy consumption, while being able to effectively avoid collisions between the transmissions from multiple IoT devices. Asynchronous Pulse-Code Multiple Access (APCMA) has been proposed as a communication protocol based on pulse-encoded signals that allows multiple senders to simultaneously transmit their messages. Even if multiple messages on the same band overlap in time during transmission, they are disentangled at the receiver by a decoding algorithm that is based on pattern matching of pulse trains. In this paper, we implement the APCMA protocol on an FPGA and evaluate its performance in wireless communication. We also implement a decoding algorithm that matches pulses by logical operations on a shift register. Our experiments show that the APCMA protocol can realize multiplexing with low overhead and that the error rate caused by misdetection during decoding is reduced with longer pulse trains.