Research on Acquisition Method of DSSS System Based on PMF-FFT
Xinyu Wang, Kun Jiang, Ran Chu, Haozhe Zhang, Changheng Wang · 2023
Spread spectrum communication, as an essential communication technique, has a wide range of applications in the real world. This article focuses on the acquisition methods in DSSS (direct sequence spread spectrum) systems. The PMF-FFT (Partial Match Filtering Fast Fourier Transform) algorithm, recognized as an excellent acquisition algorithm, combines timedomain and frequency-domain acquisition algorithms, exhibiting characteristics such as high dynamic range and fast acquisition speed. Firstly, the basic principles of the PMF - FFT algorithm are introduced, and a corresponding mathematical model is established to analyze the characteristics of this algorithm. Secondly, improvements are made in response to the practical design requirements and issues in multi-rate, multi-user communication systems. These improvements mainly include the selection of spread spectrum sequences, frame composition, and acquisition architecture. Through these improvements, the algorithm's performance is enhanced. Finally, through simulation verification at rates of 16Kbps and 128Kbps, the improved algorithm successfully achieved acquisition of eight different time slots under a significant Doppler frequency.