Reconfigurable Dual Mode IEEE 802.15.4 Digital Baseband Receiver for Diverse IoT Applications

TL;DR

This paper presents a reconfigurable dual mode receiver for IEEE 802.15.4 IoT applications, capable of switching between QPSK and MSK demodulation modes based on SNR to optimize performance and power consumption.

Contribution

It introduces a single-chip dual mode receiver exploiting the dual nature of IEEE 802.15.4 PHY, enabling adaptive demodulation for diverse IoT scenarios.

Findings

MSK detection offers low power, low complexity, and low latency.

QPSK detection achieves minimal error rates.

The receiver mode can be configured based on SNR feedback.

Abstract

IEEE 802.15.4 takes a center stage in IoT as Low- Rate Wireless Personal Area Networks(LR-WPANs). The standard specifies Offset Quadrature Phase Shift Keying Physical Layer (O-QPSK PHY) with half-sine pulse shaping which can be either analyzed under the class of M-ary PSK signals (QPSK signal with offset) or as Minimum Shift Keying (MSK) signal. M-ary PSK demodulation is requires perfect carrier and has minimal error. MSK signals which falls under Continuous Phase Frequency Shift Keying can be demodulated non-coherently but error performance is not as good. In our paper, this dual nature of IEEE 802.15.4 PHY is exploited to propose a dual mode receiver comprising of QPSK demodulator chain and MSK demodulator chain as a single system on chip. The mode can be configured manually depending on the type of application or based on the feedback from a Signal to Noise (SNR) indicator employed in the proposed receiver. M-ary PSK chain is selected for lower SNRs and MSK for higher SNRs. Each of these properties are analyzed in detail for both demodulator chains and we go on to prove that MSK detection can be used for low power, low complex and low latency while QPSK detection is employed for minimal error.