A Frequency Demodulation Technique Based on Sliding DFT Phase Locking Scheme for Large Variation FM Signals

• Published in: IEEE communications letters Vol. 16; no. 11; pp. 1864 - 1867
• Main Author: Sumathi, P.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.11.2012; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Demodulation; Deviation; Discrete Fourier transforms; Exact sciences and technology; Fourier transforms; Frequency demodulation; Frequency modulation; Harmonic analysis; Information, signal and communications theory; large deviation FM; Locking; Messages; Modulation; Modulation, demodulation; Phase frequency detector; Phase locked loops; Phase locked systems; phase locking scheme; Signal and communications theory; Sliding; sliding discrete Fourier transform; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Frequency modulation; Frequency demodulation; Large signal behavior; Modulated signal; Discrete Fourier transformation; Phase locking; Phase locked loop; Large deviation; Simulation; Second harmonic; sliding discrete Fourier transform; large deviation FM; phase locking scheme; Sinusoidal signal; Demodulation; Fundamental frequency
• ISSN: 1089-7798; 1558-2558
• DOI: 10.1109/LCOMM.2012.092812.121133

A new frequency demodulation scheme based on sliding discrete Fourier transform (SDFT) and a phase locking scheme (PLL) is proposed for extracting message signal from sinusoidal frequency modulated signals. A wide operating range of the PLL, especially the pull-in range is utilized in extracting modulation signal from the large deviation FM signals. As fundamental frequency SDFT bin is involved in the design, the SDFT PLL scheme is suitable for demodulating linear FM signals of frequency range between d.c. and second harmonic of the carrier. Simulation and experimental results prove the fast acquisition behavior and competence of the SDFT PLL in modulation signal retrieval.