Impact of a clipped phase-modulated photodiode signal on the demodulated signal

Ma, Yong; Schewe, Marvin; Bauer, Georg; Rembe, Christian

doi:10.1088/1742-6596/2041/1/012006

Cited by 2 publications

(1 citation statement)

References 5 publications

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“…When 𝑞 > 2 , the amplitude spectrum of a clipped signal 𝑈 s,clipped [𝑘] still contains the carrier component and the carrier peak amplitude 𝑈 s,clipped [𝑐] is limited by the clipping threshold 𝐾 as shown in Figure 3b for 𝑞 = 4. The results of IQ (In phase and Quadrature) demodulation for the clipped digital signal 𝑢 s, clipped [𝑛] sampled by 𝑞 > 2 cannot reflect the exact amplitude or modulation index 𝑀 of the demodulated phase 𝜑[𝑛] [40]. Therefore, in the case of 𝑞 > 2, the sampling rate can be firstly reduced to 𝑞 = 1 or 𝑞 = 2 by discarding the clipped sample points 𝑢 s,clipped [𝑛] when 𝑢 s,clipped [𝑛] = 𝐾.…”

Section: Demodulation Methods For Clipped Signalmentioning

confidence: 99%

Demodulation of phase-modulated signals with small modulation index without digital noise limitation

Schewe²,

Bauer³

et al. 2022

Preprint

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In many communication and sensor applications, receivers digitize phase-modulated carrier signals directly by analog-to-digital converters. The obtained phase-modulated digital carrier signals are numerically demodulated in order to extract the relevant information. However, the limited dynamic range of the analog-to-digital converter may reduce the carrier-to-noise ratio of carrier signals after digitization. Correspondingly, the resolution of the demodulated digital signal is degraded. We demonstrate a sampling and demodulation scheme for phase-modulated signals with a small modulation index. Our new scheme overcomes the limitation due to digital noise defined by the analog-to-digital converter. Through simulations and experiments, we provide evidence that our method can improve the resolution of the demodulated digital signal, when the carrier-to-noise ratio of phase-modulated signals is limited by digital noise. Our proposed method is applicable, for example, to solve the problem of a possible degradation of measurement resolution after digital demodulation in heterodyne interferometers measuring small vibration amplitudes.

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Section: Demodulation Methods For Clipped Signalmentioning

confidence: 99%

Demodulation of phase-modulated signals with small modulation index without digital noise limitation

Schewe²,

Bauer³

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

Improved demodulated phase signal resolution for carrier signals with small modulation index by clipping and synchronous sampling for heterodyne interferometers

Meng

Schewe

Bauer

et al. 2023

Sci Rep

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Digitization of phase-modulated carrier signals with a commercially available analog-to-digital converter (ADC) is a common task in many communication and sensor applications. ADCs deliver phase-modulated digital carrier signals, which are numerically demodulated in order to extract the relevant information. However, the limited dynamic ranges of available ADCs limit the carrier-to-noise ratio of carrier signals after digitization. Correspondingly, the resolution of the demodulated digital signal is degraded. We demonstrate a sampling method with a simple demodulation scheme for phase-modulated signals with a small modulation index. Our new scheme overcomes the limitation due to digital noise defined by the ADC. Through simulations and experiments, we provide evidence that our method can improve the resolution of the demodulated digital signal significantly, when the carrier-to-noise ratio of phase-modulated signals is limited by digital noise. We employ our sampling and demodulation scheme to solve the problem of a possible degradation of measurement resolution after digital demodulation in heterodyne interferometers measuring small vibration amplitudes.

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Impact of a clipped phase-modulated photodiode signal on the demodulated signal

Cited by 2 publications

References 5 publications

Demodulation of phase-modulated signals with small modulation index without digital noise limitation

Demodulation of phase-modulated signals with small modulation index without digital noise limitation

Improved demodulated phase signal resolution for carrier signals with small modulation index by clipping and synchronous sampling for heterodyne interferometers

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