As a promising scheme, partial transmit sequences (PTS) provides an effective solution for peak-to-average power ratio (PAPR) reduction of orthogonal frequency division multiplexing (OFDM) signals. However, the main d...
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ISBN:
(纸本)9781424437092
As a promising scheme, partial transmit sequences (PTS) provides an effective solution for peak-to-average power ratio (PAPR) reduction of orthogonal frequency division multiplexing (OFDM) signals. However, the main drawback of original PTS (O-PTS) is the large computationalcomplexity. In this paper, a reduced computational complexity partial transmit sequences (RCC-PTS) is proposed. In RCC-PTS, a low complexity phase weighting process is implemented, where the relationship between phase weighting sequences is considered and the computation for candidate signals is simplified by making use of this inherent feature. Theoretical analysis and simulation results show that, compared with O-PTS, our RCC-PTS can not only reduce computationalcomplexity clearly but also has an advantage of no loss in PAPR reduction performance.
A useful cascaded integrator comb (CIC)-based architecture is presented that improves the worst-case alias rejection of the CIC filter and simultaneously reduces the computational load of its integration section. Sinc...
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A useful cascaded integrator comb (CIC)-based architecture is presented that improves the worst-case alias rejection of the CIC filter and simultaneously reduces the computational load of its integration section. Since regularity and simplicity are acceptably preserved, the proposed design outperforms other recent CIC-based architectures from literature where these two desirable characteristics are severely affected.
Two-dimensional (2-D) adaptive digital filters (ADFs) for 2-D signal processing have become a fascinating area of the adaptive signal processing. However, conventional 2-D FIR ADF's require a lot of computations. ...
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Two-dimensional (2-D) adaptive digital filters (ADFs) for 2-D signal processing have become a fascinating area of the adaptive signal processing. However, conventional 2-D FIR ADF's require a lot of computations. For example, the TDLMS requires 2N(2) multiplications per pixel. We propose a new 2-D adaptive filter using the FFTs. The proposed adaptive filter carries out the fast convolution using overlap-save method, and has parallel structure. Thus, we can reduce the computationalcomplexity to O(log(2) N) per pixel.
Energy maximising (EM) control of wave energy converters (WECs) is a noncausal problem, where wave prediction information can be used to increase the energy conversion rate significantly. However, current approaches d...
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Energy maximising (EM) control of wave energy converters (WECs) is a noncausal problem, where wave prediction information can be used to increase the energy conversion rate significantly. However, current approaches do not consider the prediction error evolution in the control formulation process, leading to potential unpredictable performance degradation. Moreover, most existing real-time WEC control approaches assume linear dynamics, motivated by their simplicity and mild computational cost and, thus, are not effective for real-time control for WECs with nonlinear dynamics. Targeting imperfect wave prediction and nonlinear WEC dynamics, this paper proposes a computationally-efficient nonlinear MPC (NMPC) scheme for WECs with (typically) imperfect wave excitation preview. This is achieved by introducing an input move blocking scheme when formulating and solving the online optimisation problem, i.e., defining finer discretisation grids for the control input and wave prediction at the early stages of the prediction horizon, where the wave prediction is more accurate, and coarser grids at the latter stages of the horizon, to reflect less inaccurate wave prediction information. Numerical simulation results are presented, based on a conceptual nonlinear point-absorber WEC, to verify the efficacy of the proposed NMPC method, in terms of produced energy, computationalcomplexity, and robustness against wave prediction inaccuracy.
This study considers the identification problems of multiple-output non-linear equation-error moving average systems. There exist the product items of the parameters between the non-linear and linear parts. To solve t...
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This study considers the identification problems of multiple-output non-linear equation-error moving average systems. There exist the product items of the parameters between the non-linear and linear parts. To solve this difficulty, the key term separation technique is adopted. By using the model decomposition technique and the hierarchical identification principle, a maximum likelihood-based recursive extended least-squares estimation algorithm with reduced computational complexity is presented to estimate the parameters of the non-linear part and the linear part interactively. The simulation results demonstrate the effectiveness of the proposed method.
In this study, we propose several improvements of the Average Information Restricted Maximum Likelihood algorithms for estimating the variance components for genetic mapping of quantitative traits. The improved method...
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In this study, we propose several improvements of the Average Information Restricted Maximum Likelihood algorithms for estimating the variance components for genetic mapping of quantitative traits. The improved methods are applicable when two variance components are to be estimated. The improvements are related to the algebraic part of the methods and utilize the properties of the underlying matrix structures. In contrast to previously developed algorithms, the explicit computation of a matrix inverse is replaced by the solution of a linear system of equations with multiple right-hand sides, based on a particular matrix decomposition. The computational costs of the proposed algorithms are analyzed and compared.
Recently, multi-float and multi-mode-motion wave energy converters (M-WECs) have been developed to improve energy conversion capability. Although model predictive control (MPC) can be very effective to solve the const...
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Recently, multi-float and multi-mode-motion wave energy converters (M-WECs) have been developed to improve energy conversion capability. Although model predictive control (MPC) can be very effective to solve the constrained energy maximization control problem of point absorber WECs, the increased complexity of the M-WEC hydrodynamics can bring significant challenges due to computational demand. This brief proposes a novel computational-efficient fast MPC (FMPC) design method for the M-WECs requiring complex linear hydrodynamic models. The controller design objective is to maximize the energy conversion with some available wave forecasting information and to satisfy state and control input constraints to ensure safe operation. The main advantage of the proposed FMPC is the reducedcomputational burden with a negligible impact on performance. A demonstrative numerical simulation based on a 1:50 laboratory-scale M-WEC design, M4, for which linear hydrodynamics has been verified experimentally, is presented to verify the efficacy of the proposed control method in terms of both computational load and energy output.
In this letter, we present a computationally-efficient barrier function-based contraction-theoretic approach for safety verification. We adopt a dynamical system approach towards Control Barrier Function (CBF)-based Q...
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In this letter, we present a computationally-efficient barrier function-based contraction-theoretic approach for safety verification. We adopt a dynamical system approach towards Control Barrier Function (CBF)-based Quadratic Programming (QP). To mitigate the computationalcomplexity of online solutions to time-varying convex optimization, we integrate tools from contraction theory and proximal primal-dual gradient dynamics (PDGD) to provide an arbitrarily close approximation of the optimal solution. Subsequently, we adopt this result for the CBF-based QP, offering a computationally-efficient and scalable safe control design termed Control Barrier Proximal Dynamics (CBPD). The contractivity of the CBPD is then leveraged to characterize the safety of the system. We demonstrate that adopting CBPD under a technical assumption guarantees the safety specifications of the system with a bounded violation margin, which can be made arbitrarily small. Additionally, a computational analysis depicts substantial improvements in efficiency and scalability compared to the state-of-the-art. Finally, we evaluate the effectiveness of the proposed method through the simulation of a battery management problem with electro-thermal constraints.
This paper evaluates the ACRi Blind Beamforming (ABB) smart antenna algorithm which addresses the significant problem caused by high-power transmitters located in close proximity to users. Current solutions are overwh...
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ISBN:
(纸本)9780819481702
This paper evaluates the ACRi Blind Beamforming (ABB) smart antenna algorithm which addresses the significant problem caused by high-power transmitters located in close proximity to users. Current solutions are overwhelmed by the rapid increase in number and variety of strong interference sources. ABB requires less computationalcomplexity than standard algorithms, making it feasible to be added to current and next-generation systems, and provides a highly adaptive and reliable interference-resistant communications environment. Simulations show that ABB automatically nulls jamming signals that are 20 dB to 40 dB stronger than the user signal, achieving close to the theoretically best performance despite being a blind solution (no information required about the jammer or user signal) and its low computational requirements. Systems with a limited number of antennas are evaluated because legacy and current generation systems have as little as two antennas.
This paper proposes a two-stage direction-of-arrival (DOA) estimation method combining Multiple Signal Classification (MUSIC) with Sparse Bayesian Learning (SBL) algorithm. In the first stage, we take advantage of the...
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ISBN:
(纸本)9781728195070
This paper proposes a two-stage direction-of-arrival (DOA) estimation method combining Multiple Signal Classification (MUSIC) with Sparse Bayesian Learning (SBL) algorithm. In the first stage, we take advantage of the divergence of noise power spectrum and have designed an iterative MUSIC method. Performing MUSIC iteratively, we can obtain an angle set, including all estimates of DOA. Then, we transfer the angle set to the next stage to pick the correct values out. In the second stage, the angle set acquired from the iterative MUSIC is utilized to constitute the dictionary matrix used in SBL, which can decrease the computationalcomplexity effectively. Simulations indicate that the proposed method can achieve high estimation accuracy even when the Signal-to-Noise Ratio(SNR) is below 0dB with a DOA gap of 3 degrees, outperforming the conventional MUSIC and SBL algorithm.
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