scholarly journals Photoplethysmographic signal processing using adaptive sum comb filter for pulse delay measurement

2010 ◽  
Vol 16 (1) ◽  
pp. 78 ◽  
Author(s):  
K Pilt ◽  
K Meigas ◽  
R Ferenets ◽  
J Kaik
Keyword(s):  
Signal Processing ◽  
Comb Filter ◽  
Pulse Delay ◽  
Delay Measurement

Improved Raman-fibre pulse delay measurement system

1985 ◽  
Vol 21 (7) ◽  
pp. 282 ◽  
Author(s):  
A.C. van Bochove ◽  
J.F. Jacobs ◽  
H.T. Nijnuis
Keyword(s):  
Measurement System ◽  
Pulse Delay ◽  
Delay Measurement

scholarly journals A VLSI DSP DESIGN AND IMPLEMENTATION OF COMB FILTER USING UN-FOLDING METHODOLOGY

2012 ◽  
pp. 72-77
Author(s):  
PURU GUPTA ◽  
TARUN KUMAR RAWAT
Keyword(s):  
Signal Processing ◽  
Computation Time ◽  
Digital Signal ◽  
Vlsi Circuits ◽  
Comb Filter ◽  
Destructive Interference ◽  
Sample Period ◽  
Iteration Bound ◽  
Comb Filters ◽  
Digital Waveguide

In signal processing, a comb filter adds a delayed version of a signal to itself, causing constructive and destructive interference. Comb filters are used in a variety of signal processing applications that is Cascaded Integrator-Comb filters, Audio effects, including echo, flanging, and digital waveguide synthesis and various other applications. Comb filter when implemented has lower through-put as the sample period can not be achieved equal to the iteration bound because node computation time of comb filter is larger than the iteration bound. Hence throughput remains less. This paper present the comb filter using one of the methodology needed to design custom or semi custom VLSI circuits named as Un-Folding which increases the throughput of the comb filter. Un-Folding is a transformation technique that can be applied to a DSP program to create a new program describing more than one iteration of the original program. It can unravel hidden con-currency in digital signal processing systems described by DFGs. Therefore, unfolding has been used for the sample period reduction of the comb filter for its higher throughput.

scholarly journals Sampling Rate Optimization for Improving the Cascaded Integrator Comb Filter Characteristics

2021 ◽  
Vol 38 (1) ◽  
pp. 97-103
Author(s):  
Raouf Amrane ◽  
Youcef Brik ◽  
Samir Zeghlache ◽  
Mohamed Ladjal ◽  
Djamel Chicouche
Keyword(s):  
Signal Processing ◽  
Finite Impulse Response ◽  
Sampling Rate ◽  
Comb Filter ◽  
Existing Structures ◽  
High Sampling Rate ◽  
Cic Filter ◽  
Stopband Attenuation ◽  
Rate Optimization ◽  
Passband Droop

The cascaded integrator comb (CIC) filters are characterized by coefficient less and reduced hardware requirement, which make them an economical finite impulse response (FIR) class in many signal processing applications. They consist of an integrator section working at the high sampling rate and a comb section working at the low sampling rate. However, they don’t have well defined frequency response. To remedy this problem, several structures have been proposed but the performance is still unsatisfactory. Thence, this paper deals with the improvement of the CIC filter characteristics by optimizing its sampling rate. This solution increases the performance characteristics of CIC filters by improving the stopband attenuation and ripple as well as the passband droop. Also, this paper presents a comparison of the proposed method with some other existing structures such as the conventional CIC, the sharpened CIC, and the modified sharpened CIC filters, which has proven the effectiveness of the proposed method.

scholarly journals Quantitative Evaluation on Valve Leakage of Reciprocating Compressor Using System Characteristic Diagnosis Method

2020 ◽  
Vol 10 (6) ◽  
pp. 1946 ◽  
Author(s):  
Liubang Han ◽  
Kuosheng Jiang ◽  
Qidong Wang ◽  
Xuanyao Wang ◽  
Yuanyuan Zhou
Keyword(s):  
Signal Processing ◽  
Fault Diagnosis ◽  
Comb Filter ◽  
Support Vector ◽  
Complex Signal ◽  
Reciprocating Compressor ◽  
Quantitative Diagnosis ◽  
System Characteristic ◽  
Valve Leakage ◽  
Diagnosis Method

High impact and strong noise complicate the response of reciprocating compressor (RC). It requires a complex signal processing method that is a single response-based or excitation-based fault diagnosis method applied to RC valve leakage fault diagnosis. This paper proposes a quantitative diagnosis method of RC valve leakage that is based on system characteristic diagnosis method. First, the current signal of the RC induction motor and the cylinder vibration signal are introduced as the excitation and response signals, the mathematical model of the RC motor current is established, and the influence mechanism of the valve leakage on the RC vibration is analyzed. Subsequently, the ensemble empirical mode decomposition and comb filter are respectively used to extract the fault characteristic information of excitation signal and response signal to obtain the excitation condition indicators (CIs), response CIs, and system CIs. Finally, the support vector machine based on the obtained CIs classified the valve leakage failure patterns of different severity, and a fault diagnoser was constructed for the quantitative diagnosis of valve leakage fault. The results of experiment and application proved that the proposed method could realize the quantitative diagnosis of RC valve leakage fault while using simple signal processing technology.

Silicon-Based Integrated Comb Filter and Demultiplexer for Simultaneous WDM Signal Processing

2014 ◽  
Vol 20 (4) ◽  
pp. 240-247 ◽  
Author(s):  
Lei Xiang ◽  
Dingshan Gao ◽  
Yu Yu ◽  
Mengyuan Ye ◽  
Bingrong Zou ◽  
...  
Keyword(s):  
Signal Processing ◽  
Comb Filter ◽  
Silicon Based

scholarly journals DIGITAL PROCESSING OF INVESTIGATED DAC’S SIGNALS

2010 ◽  
Vol 2 (1) ◽  
pp. 45-49
Author(s):  
Tomas Ustinavičius
Keyword(s):  
Signal Processing ◽  
Digital Filters ◽  
Internal Noise ◽  
Digital Signal ◽  
Digital Processing ◽  
Periodic Sequence ◽  
Comb Filter ◽  
The Given ◽  
Very High

The article shows that in designed algorithm for determination of digital signal processing and settling time of DAC the greatest influence on the test has 1/f type internal noise of the sampling converter. It is offered to filter the preliminary digital signal and to construct pseudo-periodic sequence from n realization periods of examined signals and internal noise. It is shown, that standard digital filters because of very high the demands are not suitable. The structure of digital comb filter is proposed. Investigations have shown that the given filter can effectively be used for filtering of various signals.

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