Modeling the Impact of Phase Noise on the Performance of Crystal-Free Radios

Abstract

We propose a crystal-free radio receiver exploiting a free-running oscillator as a local oscillator (LO) while simultaneously satisfying the 1% packet error rate (PER) specification of the IEEE 802.15.4 standard. This results in significant power savings for wireless communication in millimeter-scale microsystems targeting Internet of Things applications. A discrete time simulation method is presented that accurately captures the phase noise (PN) of a free-running oscillator used as an LO in a crystal-free radio receiver. This model is then used to quantify the impact of LO PN on the communication system performance of the IEEE 802.15.4 standard compliant receiver. It is found that the equivalent signal-to-noise ratio is limited to ~8 dB for a 75- ${\mu }\text{W}$ ring oscillator PN profile and to ~10 dB for a 240- ${\mu }\text{W}$ LC oscillator PN profile in an AWGN channel satisfying the standard’s 1% PER specification.