Integrated Phase-Locking Scheme for SDFT-Based Harmonic Analysis of Periodic Signals

Sumathi, P.; Janakiraman, P.A.

doi:10.1109/tcsii.2007.907854

Cited by 49 publications

(25 citation statements)

References 8 publications

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“…Arterial wall motion parameters are estimated using phase locking schemes in [10]. A sliding discrete Fourier transform (SDFT) based phase locking scheme [62] has been applied for frequency demodulation in [63]. From a vibration measurement system, the received ultrasonic signal S 0 (t) = A 2 cos(ω 0 t + f 0 + βsin(ω L t + f L )) can be fed to the SDFT phase locking scheme.…”

Section: Wwwietdlorgmentioning

confidence: 99%

Vibration parameter estimation methods for ultrasonic measurement systems – a review

Singh

Sumathi

2015

IET Science, Measurement & Technology

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A review of vibration signal estimation techniques employed in ultrasonic vibration measurement systems is presented. The review focuses on the Doppler signal extraction methods including the theory and analysis pertaining to the background of ultrasonic vibration measurement techniques. The phase modulated received signal in the vibration measurement system involves constant phase shift because of ultrasonic path length, phase shift introduced by Doppler effect because of vibrating object and the parametric phase shift caused by interaction of high frequency ultrasonic wave and low pressure developed by vibrating object. Among the three phase shifts, the Doppler phase shift contains the vibrating signal information and the extraction of Doppler signal helps in knowing the velocity of the vibrating object, amplitude and phase of the vibration. Various techniques of Doppler phase shift retrieval are categorised based on the modulation index estimation procedures from the received ultrasonic signal. An analysis is made based on the information retrieval methods for estimation of vibration signal parameters, range of the vibration amplitude, frequency and the preferable carrier frequency for transmission. Further, the analysis also presents various applications in which ultrasonic vibration measurements system are employed successfully.

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Section: Wwwietdlorgmentioning

confidence: 99%

Vibration parameter estimation methods for ultrasonic measurement systems – a review

Singh

Sumathi

2015

IET Science, Measurement & Technology

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“…3, determines the peak of the fundamental component of a-phase voltage. A single phase digital adaptive observer [49] has been employed to achieve this. The on-line observer acts as a low pass filter and provides the fundamental component in the mains voltage u 1 = V a Á sin(xt) as well as the quadrature voltage u 2 = V a Á cos(xt).…”

Section: Sag and Swell Estimationmentioning

confidence: 99%

“…The adaptive observer acts as phase-locked-loop, while simultaneously dividing the period of the signal tracked into 128 parts. At the nominal mains frequency of 50 Hz, it also provides a pulse-train at 25.6 kHz (=4 Â 128 Â 50), which is used for generating the triangular dither at 6.4 kHz [49]. The frequency of the triangular dither signal would naturally vary in tune with the wandering mains frequency, so that the number of divisions of the mains-sine-wave remains constant at 128, enabling the use of commonly available DSP algorithms [50].…”

Section: Sag and Swell Estimationmentioning

confidence: 99%

Voltage sag and swell mitigation based on modulated carrier PWM

Rahman¹,

Janakiraman²,

Somasundaram³

2015

International Journal of Electrical Power & Energy Systems

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“…The major portion, structure 1, of the adaptive scheme comprises of sliding DFT filter, moving averager, proportional and integral (PI) controller and numerically controlled oscillator (NCO). The z-domain transfer function of SDFT filter [24] is expressed as…”

Section: Iet Communicationsmentioning

confidence: 99%

Sliding discrete Fourier transform‐based mono‐component amplitude modulation–frequency modulation signal decomposition

Sumathi

Singh

2015

IET Communications

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The sliding discrete Fourier transform-based phase locking scheme (SDFT-PLL) has been adapted for the extraction of message signals from mono-component amplitude modulation-frequency modulation (AM-FM) signals. In the proposed scheme, the SDFT-PLL is designed to track a carrier signal, which has been modulated by sinusoidal message signals both in amplitude and frequency. The sliding DFT filter is prone to windowing effect if input signal frequency drifts from centre carrier frequency. The amplitude and phase errors caused by this effect have been utilised to achieve locking condition by adaptive sampling frequency control. The SDFT-PLL is modified in such a way that the numerically controlled oscillator produces sampling pulses suitable for SDFTbin-1 and SDFT bin-0 for the retrieval of frequency and amplitude modulation signals, respectively. Hence, the frequency and amplitude variation of monocomponent AM-FM could be retrieved simultaneously. Furthermore, Bessel function-based analysis provides an insight to the removal of unwanted spectral components present in error signal. Simulation results prove the capability of PLL in message signal retrieval for large variation in frequency and amplitude. The proposed scheme is implemented in field programmable gate array to validate the performance of SDFT-PLL in decomposition of the mono-component AM-FM signal.

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Integrated Phase-Locking Scheme for SDFT-Based Harmonic Analysis of Periodic Signals

Cited by 49 publications

References 8 publications

Vibration parameter estimation methods for ultrasonic measurement systems – a review

Vibration parameter estimation methods for ultrasonic measurement systems – a review

Voltage sag and swell mitigation based on modulated carrier PWM

Sliding discrete Fourier transform‐based mono‐component amplitude modulation–frequency modulation signal decomposition

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