Authentication time is the main and important part of the authentication system. Normally the response time should be fast but as the number of persons in the database increases, there is probability of more response time taken for authentication. The need of fast authentication system arises so that authentication time (matching time) is very less. This paper proposes a sliding window approach...

We have developed a wideband digital frequency detector for high-speed frequency modulation atomic force microscopy (FM-AFM). We used a subtraction-based phase comparator (PC) in a phase-locked loop circuit instead of a commonly used multiplication-based PC, which has enhanced the detection bandwidth to 100 kHz. The quantitative analysis of the noise performance revealed that the internal noise...

We introduce definitions of the quantum efficiency for binary-outcome qubit detectors with imperfect fidelity, focusing on the subclass of quantum nondemolition detectors. Quantum efficiency is analyzed for several models of detectors, including indirect projective measurement, linear detector in binary-outcome regime, detector of the superconducting phase qubit, and detector based on tunneling...

This paper describes the implementation of a differential Continuous Phase FSK (CPFSK) detector suitable for Low-IF receiver architectures. By using both in-phase and quadrature channels the double frequency term resulting after differential detection can be avoided. The digital detector assumes limited I/Q input signals which are 16 times oversampled. The proposed detector can be used for CPFS...

In a classical PLL, the phase detector (PD) and charge pump (CP) noise is multiplied by N, when referred to the VCO output, due to the divide-by-N in the feedback path. It often dominates the in-band phase noise and limits the achievable PLL jitter•power Figure-Of-Merit (FOM). A sub-sampling PLL uses a PD that sub-samples the high frequency VCO output with the reference clock. The PD and CP noi...

Why are different mass states coherent? What is the correct formula for the oscillation phase? How can textbook formulas for oscillations in time describe experiments which never measure time? How can we treat the different velocities and different transit times of different mass eigenstates and avoid incorrect factors of two? How can textbook forumulas which describe coherence between energy s...

Concepts for the generation and the measurement of highly linear frequency ramps are presented. The fractional ramp synthesiser concept shown here is able to generate frequency ramps with a very low phase noise level, a very good frequency linearity and reproducibility. Related to the bandwidth of the generated frequency ramps of 4.5 GHz a relative linearity error below 4·10−10 is demonstrated ...

Controlled intersymbol interference may be used to design bandwidth efficient coded modulation schemes. The performance of the optimum receiver depends only on the free distance of the code and is independent of its phase. Large reductions in receiver complexity are obtained by using reduced search detection techniques like the MAlgorithm (MA). However, we show that MA detector performance depe...