Robust and Accurate Packet Detection and Frequency Offset Compensation for CSS System

In this paper, we propose a new robust packet detection and frequency offset compensation structure for IEEE 802.15.4a chirp spread spectrum (CSS) which is a standard for wireless personal area network (WPAN). The proposed structure takes benefits of both cross- and auto-correlation. Cross-correlation is useful to remove additional side band noise in the CSS system and to find sharp peaks among filtered output values. In addition, we use the auto-correlation in order to suppress the effect of frequency offset and the initial channel phase. Simulation results show that the proposed procedure is robust to the frequency offset, and can detect the presence of a signal in very low signal to noise ratio (SNR).