Automatic protocol configuration in single-channel low-power dynamic signaling for IoT devices

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Pulsed-Index Communication (PIC) is a novel technique for single-channel, high-data rate, low-power dynamic signaling that does not require any clock and data recovery. It is fully adapted to the simple yet robust communication needs of Internet of Things (IoT) devices and sensors. However, its error-free operation with maximum data rate requires a careful and judicious setting of PIC data packet and pulse timing parameters. In this paper, we present a new algorithm for automatically detecting and setting the PIC protocol parameters at the power-on phase while removing the restriction on the IoT devices in the PIC network to communicate at a baud rate. The hardware realization of the algorithm is power-efficient and uses closed-form formulas that assign suitable protocol parameters to both ends of the transmission link based on clock rate differences. This difference is determined by a preliminary exchange of clock pulse streams between the transmitter and the receiver. The automatic parameter setting remains operational even in the presence of variations between the local clock frequencies of the IoT devices communicating via PIC. The algorithm is illustrated in the case of several IoT devices with different local clock frequencies that are in need to synchronize their communication parameters with respect to the clock frequency of a master gateway node. A power-on PIC parameter configuration process is rigorously specified, and both an FPGA and an ASIC implementations are presented. In particular, we show that for an ASIC implementation in 65nm technology, the low-power operation of PIC is maintained, consuming only 4.35µW of power at a clock frequency of 25MHz. This architecture is experimentally verified and tested on a point-to-point communication link between two IoT devices connected via a single PIC channel in a master-slave mode.