Frequency Offset Insensitive Multiple Symbol Differential Detection Scheme for IEEE 802.15.4 BPSK Receivers

A simple frequency offset insensitive multiple-symbol differential detection (MSDD) scheme is proposed for IEEE 802.15.4 binary phase shift keying (BPSK) receivers. The detection is initiated by estimating and compensating the carrier frequency offset (CFO) effect in the chip sample. With these compensated statistics, the decisions are jointly made by allowing the observation window length to be longer than two bit intervals. Simulation results demonstrate that, at packet error rate (PER) of 1×10^-3, the chip signal-to-noise ratio (SNR) gap between the ideal coherent detection (perfect carrier reference phase and no CFO) with differential decoding and conventional optimal single differential coherent detection (SDCD) is filled by 2.1 dB when the observation window length is set to be 6 bit intervals. Namely, detection reliability of the present IEEE 802.15.4 BPSK receivers is significantly improved. Then, the benefit that less energy consumed by retransmissions is successfully achieved.