Code and carrier synchronization for IEEE 802.15.4K DSSS PHY

摘要

IEEE 802.15.4k standard is mainly designed for Low Energy Critical Infrastructure Monitoring Networks (LECIM) whose direct sequence spread spectrum physical layer (DSSS PHY) requires the properties of long deployment lifetime and high receiver sensitivity. To save energy and realize the reliable data detection at low SNR situation, the estimation of synchronization parameters, i.e. carrier frequency offset and code initial phase from the received signal is of great importance. In this paper, we propose a fast, open-loop, all-digital signal acquisition technique which is widely used to get the carrier frequency and initial code phase. Fast Fourier Transform (FFT) combined with quadratic interpolation is used to implement carrier synchronization. Auto-correlation of Gold code is used for code synchronization by correlating the receive signal with local sequences. Besides, the performance of the estimator is analyzed in detail and simulation results are shown. Finally, by altering the parameters such as despread factor, FFT size and interpolation number, we have proposed a scheme of code and frequency synchronization for IEEE 802.15.4k DSSS PHY.