Input Amplitude Compression in Digital Signal-Detection Systems

1981 ◽  
Vol 29 (5) ◽  
pp. 707-710 ◽  
Author(s):  
H. Poor ◽  
Y. Rivani
Author(s):  
A.C.T. Quah ◽  
J.C.H. Phang ◽  
L.S. Koh ◽  
S.H. Tan ◽  
C.M. Chua

Abstract This paper describes a pulsed laser induced digital signal integration algorithm for pulsed laser operation that is compatible with existing ac-coupled and dc-coupled detection systems for fault localization. This algorithm enhances laser induced detection sensitivity without a lock-in amplifier. The best detection sensitivity is achieved at a pulsing frequency range between 500 Hz to 1.5 kHz. Within this frequency range, the algorithm is capable of achieving more than 9 times enhancement in detection sensitivity.


2021 ◽  
pp. 108-114
Author(s):  
D.D. Privalov

The sampling rate at a given bit rate is a requirement for the speed of digital signal processors. In this regard, it is necessary to strive to reduce it in the development of electronic devices, especially portable ones. However, this can lead to an increase in the bit error rate during signal detection. Therefore, it is important to determine the degradation of signal detection with decreasing sampling frequency and to develop practical recommendations to ensure the specified quality of communication. The aim of the article is to study the influence of sampling frequency and interpolation on the bit error rate of GMSK Signal. The article considers the incoherent detection of a GMSK signal in a channel with additive white Gaussian noise, taking into account the influence of the clock synchronization error. Numerical results are presented that characterize an increase in the bit error rate with a decrease in the signal sampling frequency. It is shown that when using the cubic Farrow interpolator, there is no significant degradation in the bit error probability. The minimum number of samples per symbol is determined, at which the bit error rate is close to the theoretical values in the absence of synchronization error. The presented results can be used in development of wireless data transmission systems.


1990 ◽  
Vol 36 (11) ◽  
pp. 1897-1901 ◽  
Author(s):  
P Vilja

Abstract I adapted the noncompetitive avidin-biotin immunoassay (NABA) of lutropin (LH) for use with radiometric, fluorometric, time-resolved fluorometric, and luminometric detection systems by changing the enzyme substrate or conjugating avidin with different labels. The corresponding methods were used to determine LH in 40 urine samples, and the results were compared with those obtained by an immunoenzymometric assay (IEMA), also based on the NABA principle. Scatter plots of the results showed a linear relation with high correlation coefficients (r = 0.972-0.983), and bias plots showed good agreement between the four comparison methods and the IEMA. The results indicate that the effectiveness of the NABA of LH is independent of the signal detection system. This means good flexibility for the user in choice of instrument and signal detection system.


2012 ◽  
Vol 19 (1) ◽  
pp. 95-104
Author(s):  
Adam Rutkowski

A Concept of a Passive Radar with Quadrature Microwave Phase Discriminators Passive radar does not have its own emitter. It uses so-called signals of opportunity emitted by non-cooperative illuminators. During the detection of reflected signals, a direct signal from a non-cooperative emitter is used as the reference signal. Detection of electromagnetic echoes is, in present day radars, performed by finding the maximum of the cross ambiguity function. This function is based on the multiplication of the received signal and the reference signal. Detection of echoes by means of a quadrature microwave phase discriminator QMPD was proposed in the work as an alternative solution for ambiguity function evaluation. This discriminator carries out vectorial summing of the received and the reference signals. The summing operations in QMPD are carried out with the aid of microwave elements and without the use of expensive digital signal processors. Definitions of the phase and phase difference of the so-called simple signals and noise signals were described. A proposal of a passive radar equipped with several independent quadrature microwave phase discriminators was presented. Ideas of algorithms of object detection and of the distance-to-object estimation designed for this radar have been also sketched.


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