A modified cascaded FFT acquisition algorithm for tiered spreading code

作者：Li Yangzhi^*; Li Guangxia; Cheng Jian; Luo Kui; Lv Jing

来源：International Journal of Digital Content Technology and Its Applications, 2011, 5(7): 25-31.

DOI：10.4156/jdcta.vol5.issue7.4

• Acquisition
• Cascaded FFT
• Correlation loss
• Discontinuity problems
• FFT (fast Fourier transform)
• FFT acquisition
• Frame overlap
• Frequency domains
• Global Navigation Satellite Systems
• Modified algorithms
• Phase compensation
• Signal acquisitions
• Simulation result
• Spectrum shifts
• Spreading codes

The tiered spreading codes which are adopted in GNSS (Global Navigation Satellite System) increase the difficulties of signal acquisition. This paper investigates the cascade FFT(Fast Fourier Transform) algorithm applied to the acquisition of tiered spreading codes. A deficiency of the algorithm lie in implementation is under consideration, the phase discontinuity. When utilizing the frequency domain spectrum shift technique in acquisition, subsection FFT operation leads to the phase discontinuity, which results in correlation loss and acquisition failure. A modified algorithm suitable for practical application is proposed. The modified algorithm adopts phase compensation method to solve the phase discontinuity problem. Simulation results show the modified algorithm can avoid the correlation loss and acquire the tiered spreading code effectively.

• 出版日期2011