Direction of Arrival (DOA) estimation remains a pivotal aspect in the field of signalprocessing, finding applications across diverse domains. This paper introduces an innovative approach to DOA estimation by integrat...
详细信息
ISBN:
(纸本)9798350361261;9798350361278
Direction of Arrival (DOA) estimation remains a pivotal aspect in the field of signalprocessing, finding applications across diverse domains. This paper introduces an innovative approach to DOA estimation by integrating adaptive beamforming techniques. We start by exploring the adaptive array theory, focusing on pattern synthesis and beamforming algorithms to enhance signal clarity and direction detection. The paper then delves into the application of Machine Learning (ML) algorithms for dynamic environment adaptation and improved accuracy in DOA estimation. Our approach contrasts the conventional methods by leveraging adaptive beamforming combined with ML, resulting in not only enhanced estimation accuracy but also in adaptability to varying signal conditions. The paper presents comparative analyses with traditional methods, demonstrating the potential of this integrated approach in complex signal environments.
We propose two-dimensional signal gating for high-performance multipliers including tree multipliers and array multipliers with an upper/lower left-to-right leapfrog (ULLRLF) structure. In ULLRLF array multipliers, th...
详细信息
ISBN:
(纸本)0819450782
We propose two-dimensional signal gating for high-performance multipliers including tree multipliers and array multipliers with an upper/lower left-to-right leapfrog (ULLRLF) structure. In ULLRLF array multipliers, the G-Y gating line follows the boundary of existing upper/lower partitioning. The G-X gating line goes through the upper and lower LRLF arrays. In tree multipliers, the G-Y gating line follows the existing partitioning of tree branches. The G-X line goes through all carry-save adders for partial product reduction. Because of the irregularity of the tree reduction structure, signal gating in tree multipliers is more complex than that in array multipliers. Experimental results indicate that two-dimensional gating is quite efficient in high-performance multipliers, with 65% power reduction under test data with large dynamic range.
Novel arithmetic units are needed to achieve the cost, performance, power, and functionality requirements of emerging multimedia systems. This paper presents the design and implementation of a 64-bit arithmetic and lo...
详细信息
ISBN:
(纸本)0819450782
Novel arithmetic units are needed to achieve the cost, performance, power, and functionality requirements of emerging multimedia systems. This paper presents the design and implementation of a 64-bit arithmetic and logic unit (ALU) for multimedia processing. The 64-bit ALU supports subword-parallel processing by allowing one 64-bit, two 32-bit, four 16-bit, or eight 8-bit operations to be performed in parallel. In addition to conventional ALU operations, the ALU also supports several operations for enhanced multimedia processing including parallel compare, parallel average, parallel minimum, parallel maximum, and parallel shift and add. To efficiently implement a variety of multimedia applications, the ALU supports saturating and wrap-around arithmetic operations on unsigned and two's complement operands. This paper compares the area and delay of the 64-bit multimedia ALU to those of a more conventional 64-bit ALU.
作者:
Schumer, SeanUSA
Acoust & Networked Sensors Div ARDEC RDAR MEF A Picatinny Arsenal NJ 07806 USA
This paper introduces a method of enhancing an unattended ground sensor (UGS) system's classification capability of humans via seismic signatures while subsequently discriminating these events from a range of othe...
详细信息
ISBN:
(纸本)9781457705397
This paper introduces a method of enhancing an unattended ground sensor (UGS) system's classification capability of humans via seismic signatures while subsequently discriminating these events from a range of other sources of seismic activity. Previous studies have been performed to consistently discriminate between human and animal signatures using cadence analysis. The studies performed herein will expand upon this methodology by improving both the success rate of such methods as well as the effective range of classification. This is accomplished by fusing multiple seismic axes in real-time to separate impulsive events from environmental noise. Additionally, features can be extracted from the fused axes to gather more advanced information about the source of a seismic event. Compared to more basic cadence determination algorithms, the proposed method substantially improves the detection range and correct classification of humans and significantly decreases false classifications due to animals and ambient conditions.
Modern acoustic signalprocessing is often a combination of sound propagation physics and advancedsignalprocessingalgorithms, which involves intensive acoustic, environmental, and statistical modeling. This paper d...
详细信息
ISBN:
(纸本)9780933957398
Modern acoustic signalprocessing is often a combination of sound propagation physics and advancedsignalprocessingalgorithms, which involves intensive acoustic, environmental, and statistical modeling. This paper discusses three different statistical signal models in low-frequency matched-field processing accounting for different source and channel conditions, and presents the Cramer-Rao bound (CRB) associated with each model. CRB evaluation examples show that under the same signal-to-noise ratios, the source localization performance degrades with increasingly-complicated as well more realistic data models.
Many system and signal related problems involve matrix inversion of some kind. For example, in estimation and signal recovery applications, inversion of the channel response matrix is often required in order to estima...
详细信息
ISBN:
(纸本)0819450782
Many system and signal related problems involve matrix inversion of some kind. For example, in estimation and signal recovery applications, inversion of the channel response matrix is often required in order to estimate the source signals. In the control of multivariable systems, inverting a process gain matrix may be called for in order to deliver appropriate control actions. There are situations where these matrices should be considered as uncertain (or random): for example, when the process/channel environments vary randomly, or when significant uncertainties are involved in estimating these matrices. Based on a unified approach, this paper considers both the right inversion (for control) and the left inversion (for estimation) of random matrices. In both cases, minimizing a statistical error function leads to the determination of optimal or linear optimal inversion. Connections with related techniques, such as the total least squares (TLS), the ridge regression, the Levenberg-Marquardt algorithm and the regularization theory are discussed. A variant Kalman filtering problem with randomly varying measurement gain matrix is among the applications addressed. Monte Carlo simulation results show substantial benefits by taking process/model uncertainty into consideration.
A new feature set and decision function are proposed for classifying transient wandering-tone signals. signals are partitioned in time and modeled as having piecewise-linear instantaneous frequency and piecewise-const...
详细信息
ISBN:
(纸本)0819445584
A new feature set and decision function are proposed for classifying transient wandering-tone signals. signals are partitioned in time and modeled as having piecewise-linear instantaneous frequency and piecewise-constant amplitude. The initial frequency, chirp rate, and amplitude are estimated in each segment. The resulting sequences of estimates are used as features for classification. The decision function employs a linear Gaussian dynamical model, or hidden Gauss-Markov model (HGMM). The parameters that characterize the HGMM for each class are estimated from labeled training sequences, and the trained models are used to evaluate the class-conditional likelihoods of an unlabeled signal. The signal is assigned to the-class whose model gives the maximum conditional likelihood. Simulation experiments demonstrate perfect classification performance in a three-class forced-choice problem.
An adaptive algorithm and two stage filter structure were developed for adaptive filtering of certain classes of signals that exhibit cyclostationary characteristics. The new modified P-vector algorithm (mPa) eliminat...
详细信息
ISBN:
(纸本)0819422347
An adaptive algorithm and two stage filter structure were developed for adaptive filtering of certain classes of signals that exhibit cyclostationary characteristics. The new modified P-vector algorithm (mPa) eliminates the need for a separate desired signal which is typically required by conventional adaptive algorithms. It is then implemented in a time-sequenced manner to counteract the nonstationary characteristics typically found in certain radar and bioelectromagnetic signals. Initial algorithm testing is performed on evoked responses generated by the visual cortex of the human brain with the objective, ultimately, to transition the results to radar signals. Each sample of the evoked response is modeled as the sum of three uncorrelated signal components, a time-varying mean (M), a noise component (N), and a random jitter component (Q). A two stage single channel time-sequenced adaptive filter structure was developed which improves convergence characteristics by de coupling the time-varying mean component from the `Q' and noise components in the first stage. The EEG statistics must be known a priori and are adaptively estimated from the pre stimulus data. The performance of the two stage mPa time-sequenced adaptive filter approaches the performance for the ideal case of an adaptive filter having a noiseless desired response.
作者:
Pitton, JWMathSoft
Seattle WA 98109 1700 Westlake Ave N United States
An algorithm for computing positive time-frequency distributions (TFDs) for nonstationary signals is presented. This work extends the earlier work of the author and his colleagues in computing positive TFDs [11, 15]. ...
详细信息
ISBN:
(纸本)0819425842
An algorithm for computing positive time-frequency distributions (TFDs) for nonstationary signals is presented. This work extends the earlier work of the author and his colleagues in computing positive TFDs [11, 15]. A general approach to the problem of computing these signal-dependent distributions is derived. The method is based on an evolutionary spectrum formulation of positive TFDs. Following earlier work [15], a relationship is derived between positive TFDs and the ambiguity function of the observed signal. In particular, it is shown that the TFD is approximately equal to the two-dimensional Fourier transform of the ambiguity function. A method for computing the positive TFD is then presented based on minimizing the squared error in this approximation subject to the TFD being positive and satisfying the time and frequency marginals. The squared error may be weighted non-uniformly, resulting in a constrained weighted least-squares optimization problem. A solution to this optimization problem based on an alternating projections framework is presented, and an example is provided. The resulting TFD provides excellent time-frequency resolution while maintaining positivity and satisfying the marginals.
Detection and estimation of harmonic signals embedded in noise is one of the most encountered problems in the signalprocessing area. Much research has been done for solving such a problem regarding its importance in ...
详细信息
ISBN:
(纸本)0819419222
Detection and estimation of harmonic signals embedded in noise is one of the most encountered problems in the signalprocessing area. Much research has been done for solving such a problem regarding its importance in many applications. Second order statistics have been used extensively by many authors such as Whittle, Bartlett, Hannan, and Priestley. Each of them proposed a test for harmonic signal detection. However, most of these tests have been proposed under the Gaussina assumption. As a matter of fact, when the the noise is non- Gaussian, statistics of higher order could provide much more information. This is where this paper is directed. We particularly focus our attention on the third and fourth order cumulant methods. Statistical tests based on an extension of the existing tests are used and their efficiency analyzed and discussed.
暂无评论