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Spectral testing and linearity testing are two important categories in ADC testing. The sampling clock quality is a crucial factor in ADC spectral testing. The cumulative clock jitter of the sampling clock generates power leakage in the fundamental component of the ADC output spectrum, and the random clock jitter increases the noise floor of the ADC output spectrum, which corrupts the spectrum result...
Two-dimensional zero-attraction projection (2DZAP) algorithm for single snapshot direction of arrival (DOA) estimation is proposed in this paper. Compared with the traditional DOA estimation, the proposed 2D-ZAP algorithm can estimate DOA exactly by ℓ-norm with the same number of sensors, although each sensor samples the signal only one time. In addition, 2D-ZAP algorithm can reduce the noise interference...
One-dimensional (1D) compressive sensing is often adopted in traditional sparse target detection of pulse Doppler radar. However, the 1D sparse target detection problem often requires large computational memory due to large measurement matrix. To solve this problem, this paper proposes a two-dimensional iterative hard thresholding algorithm (2D-IHT) for CS-based pulse Doppler radar to directly detect...
To meet 1000x wireless traffic volume increment in the next decade, a larger number of small base stations (SBSs) have to be densely deployed for 5G cellular networks. Analyzing the optimal density of small base station from the perspective of energy efficiency is very meaningful for green 5G mobile networks. In this paper, we analyze the SBS density for energy efficiency in ultra-dense heterogeneous...
A method for separating and accurately estimating ADC noise, aperture jitter, and clock jitter is presented for ADC testing and characterization. This significantly relaxes clock jitter requirements and removes the need for high precision test instruments, but still allows ADC specifications like SNR, SNDR and ENOB to be accurately estimated.
Sparse adaptive filtering algorithms are utilized to exploit potential sparse structure information as well as to mitigate noises in many unknown sparse systems. Sparse recursive least square (RLS) algorithms have been attracted intensely attentions due to their low-complexity and easy- implementation. Basically, these algorithms are constructed by standard RLS algorithm and sparse penalty functions...
Adaptive sparse system identification (ASIDE) techniques have been successfully applied in many applications, such as sparse channel estimation and radar target detection. Normalized least mean fourth (NLMF)-type algorithms are considered as one of the stable ASIDE techniques even at low signal-to-noise ratio (SNR). However, the convergence capability of sparse NLMF algorithms is severely decreased...
Clock jitter is a crucial factor in high speed and high performance Analog-to-Digital Converter (ADC) testing. Random clock jitter increases the noise floor in the ADC output spectrum making it difficult to obtain the true ADC Signal to Noise Ratio (SNR). Periodic Jitter generates spurs in the ADC output spectrum. Another well-known challenge is to achieve precise coherent sampling. This paper proposes...
Underdetermined inverse sparse signal reconstruction problems in the presence of non-Gaussian noise interference are often encountered in high-mobility wireless communications and signal processing. These problems can be solved by finding the minimizer of a suitable objective function which consists of a data-fitting term and a regularization term with different mixed-norms. Based on the Gaussian-noise...
Nonlinear sparse sensing (NSS) techniques have been adopted for realizing compressive sensing (CS) in many applications such as Radar imaging and sparse channel estimation. Unlike the NSS, in this paper, we propose an adaptive sparse sensing (ASS) approach using reweighted zero-attracting normalized least mean fourth (RZA-NLMF) algorithm which depends on several given parameters, i.e., reweighted...
To estimate multiple-input multiple-output (MIMO) channels, invariable step-size normalized least mean square (ISSNLMS) algorithm was applied to adaptive channel estimation (ACE). Since the MIMO channel is often described by sparse channel model due to broadband signal transmission, such sparsity can be exploited by adaptive sparse channel estimation (ASCE) methods using sparse ISS-NLMS algorithms...
Cluster-sparse channels often exist in frequency-selective fading broadband communication systems. The main reason is received scattered waveform exhibits cluster structure which is caused by a few reflectors near the receiver. Conventional sparse channel estimation methods have been proposed for general sparse channel model which without considering the potential cluster-sparse structure information...
Jitter is a crucial factor in high speed and high performance ADC testing. This paper proposes an efficient and accurate jitter estimation method based on one frequency measurement. Applying simple mathematical processing to the ADC output in time domain, the RMS of jitter and noise power are obtained. Furthermore, prior information of harmonics does not need to know before the processing. The algorithm...
In Built-In Self-Test, it is hard to control the amplitude of the input sine wave approximately equal but slightly less than the full scale of the ADC under test, under which condition correct spectral performance can be obtained. This paper proposes a new algorithm which can achieve accurate testing result when the input sine wave is larger than the full scale of the ADC. It also relaxes an IEEE...
The vector sensor can be competent for measuring the information of pressure and velocity synchronously and independently. Acoustic multi user communication system based on single vector sensor, which can be used to separate several source from each other by calculating the inverse channel matrix, can be equivalent to MIMO system. Theoretical calculation and simulation have shown that the algorithm...
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