Sensitivity Analysis of a Low-Power Wake-Up Receiver Using an RF Barker Code SAW Correlator and a Baseband Narrowband Correlator

Abstract

In this paper we propose a novel low-power receiver architecture which uses a direct-detection receiver in combination with a 2.44 GHz 13 bit Barker Code SAW correlator for improvement of co-channel interference. Furthermore, to improve receiver sensitivity, a narrowband baseband correlator which uses pulse position modulation (PPM) is proposed. The receiver can be used as a Wake-up Receiver (WuRx) in Wireless Sensor Networks (WSN) to minimize the power dissipation and provide asynchronous and on-demand data communication. We present a rigorous analysis of the receiver. It shows that the RF front-end (SAW correlator and envelope detector) alone suffers from poor sensitivity due to the high baseband bandwidth and the absence of an RF low noise amplifier. However, by adding the narrowband correlator with an innovative Pulse Position Modulation (PPM) scheme, the overall sensitivity of the receiver reaches -63.1 dB with an improvement of 17.7 dB due to the use of the narrowband correlator that reduces the baseband bandwidth from 50 to 0.84 MHz. By scaling the narrowband correlator bandwidth further down, the receiver sensitivity can be further improved.