In this paper we investigate the ''global convergence'' phenomenon of the Steiglitz-McBridge adaptive identification/filtering method (SMM) observed previously under reduced order setting. Specifically...
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In this paper we investigate the ''global convergence'' phenomenon of the Steiglitz-McBridge adaptive identification/filtering method (SMM) observed previously under reduced order setting. Specifically, we relate the closeness of SMM solutions to minimum mean square error (MSE) points through sharpness of the MSE surface at these minima. We first define the sharpness, and then propose that generally global minima are sharper than local minima. A local analysis based on the first-order case then reveals that the smaller the MSE is and the sharper a minimum is, the closer the SMM solution will be to the minimum. This explains the striking closeness of the two points observed earlier. Some additional first-order examples are also presented that all agree with the results of the analysis. These local results are then generalized to higher order cases. The global properties of the SMM solutions are finally proposed in the form of a conjecture which is based on numerous calculated examples.
The multipath equalization time delay estimator (METDE) provides;an adaptive approach for estimating the difference in arrival times of a signal received at spatially separated sensors as well as the multipath channel...
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The multipath equalization time delay estimator (METDE) provides;an adaptive approach for estimating the difference in arrival times of a signal received at spatially separated sensors as well as the multipath channel characteristics. However, the parameter estimates of the METDE are biased in the presence of noise. The METDE algorithm is improved for unbiased parameter estimation via minimizing a modified cost function. Convergence behaviors and variances of the system variables of the amended method are derived. Computer simulations are included to corroborate the theoretical analysis and to evaluate the adaptive multipath delay estimation performance of the proposed algorithm.
In this paper, a probabilistic modification of the minimal element algorithm for solving the axial three-index assignment problem is suggested. Its general idea is to extend the basic greedy-type algorithmic schemes u...
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In this paper, a probabilistic modification of the minimal element algorithm for solving the axial three-index assignment problem is suggested. Its general idea is to extend the basic greedy-type algorithmic schemes using transition to a probabilistic setup based on variables randomization. The minimization of an objective function is replaced by the minimization of its expectation. The algorithm is implemented in three stages as follows. At the first stage, a motion in the set of random variables is defined. At the second stage, an inequality that expresses the local improvement condition is solved. At the third stage, the probabilities are recalculated, which represents an adaptation process. The second stage reveals a feature of the algorithm: the resulting solution depends on the qualities of the element itself and also on possible losses of its choice.
A new block-type adaptive-filtering algorithm is presented. This new block adaptive filter differs from the frequency-domain block adaptive filters of Ferrara (1980), and of Clark, Mitra, and Parker (1980), in that th...
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A new block-type adaptive-filtering algorithm is presented. This new block adaptive filter differs from the frequency-domain block adaptive filters of Ferrara (1980), and of Clark, Mitra, and Parker (1980), in that the new method applies a deterministic time-domain least-squares criteria within each of the data blocks. Information is carried from block to block via a weighted initial condition. This new block fast transversal filters (BFTF) algorithm is a numerically stable algorithm and can also be used to perform efficient least-squares system identification on any one data block, in which case it shows a moderate computational advantage over the previous most-efficient single-data-block algorithms of Morf et al. (1977), of Marple (1981), and of Kalouptsidis, Manolakis, and Carayannis (1984-1985). Mechanisms for tracking and varying block length from block to block are also presented and evaluated. Finally, we indicate how the new algorithm could be pipelined for maximum throughput with delay proportional to the number of parameters, after computation of the sample correlation lags.
The complex direct frequency estimation (CDFE) adaptive algorithm is developed and proposed in this paper. The motivation of this work is obtained from the previous real DFE (RDFE) adaptive algorithm. The methodology ...
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The complex direct frequency estimation (CDFE) adaptive algorithm is developed and proposed in this paper. The motivation of this work is obtained from the previous real DFE (RDFE) adaptive algorithm. The methodology of the CDFE is based on the linear prediction property of complex sinusoidal signals. The proposed algorithm is unbiased and computationally efficient. Moreover, it is easy to implement and appropriate for real-time applications. In addition, the convergence behavior is analyzed and the steady-state mean square error (MSE) of the frequency estimate is derived in closed form. Computer simulations are treated to corroborate the theoretical analysis. (C) 2012 Elsevier GmbH. All rights reserved.
A new algorithm for spatially filtering out, enhanceing, and tracking individual directional sources in an adaptive array is proposed and investigated. In this algorithm, the sources are separated by using an adaptive...
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A new algorithm for spatially filtering out, enhanceing, and tracking individual directional sources in an adaptive array is proposed and investigated. In this algorithm, the sources are separated by using an adaptive beamformer whose outputs are processed by employing the LMS algorithm to track distinct sources individually. From the LMS weights employed, the source locations can be estimated and whenever significant changes in these are detected, the beamformer is updated so that its outputs will be due to different sources in the steady state. With this algorithm, the problems of look direction errors in look-direction constrained arrays and of large signal power in power inversion arrays are eliminated, and the enhancement of multiple moving sources becomes a natural process. Furthermore, because the sources are individually tracked and the beamformer is only updated occasionally, the algorithm possesses fast tracking behavior, and its implementation complexity is comparable to that of beamformer-based adaptive arrays using the LMS algorithm.
This correspondence studies the effect of a nonzero delay on the performance of the leaky LMS algorithm, The stability bound on the stepsize is derived for error convergence, It is shown that leakage allows for larger...
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This correspondence studies the effect of a nonzero delay on the performance of the leaky LMS algorithm, The stability bound on the stepsize is derived for error convergence, It is shown that leakage allows for larger bounds on the step size of the delayed LMS algorithm, Theoretical bounds are verified by simulations.
One of the main problems facing beamforming in smart antenna system is the alpha-stable noise. To address this problem, a novel algorithm, named the recursive continuous logarithmic mixed p-norm (RCLMP) algorithm, whi...
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One of the main problems facing beamforming in smart antenna system is the alpha-stable noise. To address this problem, a novel algorithm, named the recursive continuous logarithmic mixed p-norm (RCLMP) algorithm, which employs a logarithmic cost, is proposed in this brief. The proposed algorithm combines the logarithmic p-norms 1 <= p <= 2 which does not need the parameter selection and prior knowledge of astable noise, and exhibits good robustness against alpha-stable noise. Moreover, we show some H-infinity norm bounds for the proposed algorithm. Simulation results show that the RCLMP algorithm outperforms the existing algorithms in terms of interference rejection capability and estimation accuracy.
Closed-loop power control in the reverse link of a DS/CDMA system is analysed. The transmitter/receiver based on IS-95 and the radio propagation channel under mobile communication environments are modelled and a new p...
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Closed-loop power control in the reverse link of a DS/CDMA system is analysed. The transmitter/receiver based on IS-95 and the radio propagation channel under mobile communication environments are modelled and a new power control algorithm is proposed. This algorithm utilises the burst error characteristics of the channel and can be directly applied to the current IS-95 system. The new power control algorithm. with respect to the SIR (signal to interference ratio), increases;he service quality, and finally, enhances the system capacity.
The application of an innovations-based detection algorithm (IBDA) in moving target detector (MTD) radars has been shown to be efficient. In this correspondence, an adaptive algorithm for the IBDA is derived. This alg...
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The application of an innovations-based detection algorithm (IBDA) in moving target detector (MTD) radars has been shown to be efficient. In this correspondence, an adaptive algorithm for the IBDA is derived. This algorithm behaves well in numerical properties and computational complexity. Also, it possesses high computing parallelism and data locality which lead to the feasibility of VLSI array realization. A systolic array is designed with the iteration time being (2n + 1) and the number of processing elements being [(n2 + 3n)/2], where n is the length of the adaptive filter.
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