| 1. |
- Assimonis, Stylianos D., et al.
(författare)
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Improved parametric families of intersymbol interference-free Nyquist pulses using inner and outer functions
- 2011
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Ingår i: IET Signal Processing. - : Institution of Engineering and Technology (IET). - 1751-9675 .- 1751-9683. ; 5:2, s. 157-163
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Tidskriftsartikel (refereegranskat)abstract
- In this article, the authors introduce and study the performance of two novel parametric families of Nyquist intersymbol interference-free pulses. Using only two design parameters, the proposed pulses yield an enhanced performance compared to the sophisticated flipped-inverse hyperbolic secant (asech) filter, which was recently documented in the literature. Although the construction of parametric families originates from the work of Beaulieu and Damen, the authors' approach is based on the concept of ‘inner’ and ‘outer’ functions and for this reason a higher flexibility in the choice of the family members is achieved. The proposed pulses may decay slower than the original raised-cosine (RC) pulse outside the pulse interval, but exhibit a more pronounced decrease in the amplitudes of the two largest sidelobes and this accounts for their improved robustness to error probabilities. It is clearly shown, via simulation results, that a lower bit error rate (BER), compared to the existing pulses, can be achieved for different values of the roll-off factor and timing jitter. Moreover, a smaller maximum distortion as well as a more open-eye diagram are attained which further demonstrate the superiority of the proposed pulse shaping filters.
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| 2. |
- Gupta, Payal, et al.
(författare)
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Improved resolving capabilities of linear array using 2 q th order non‐circular statistics
- 2021
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Ingår i: IET Signal Processing. - : The Institution of Engineering and Technology. - 1751-9675 .- 1751-9683. ; 15:2, s. 61-79
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Tidskriftsartikel (refereegranskat)abstract
- Resolving more sources than sensors is always of interest to researchers. For this purpose, generation of the virtual array from the non-uniform linear array has recently gathered a lot of attention. The covariance/cumulant lags of the array output define virtual sensors and thereby virtual array. The aperture of the designed virtual array is much more than the aperture of physical array. This large aperture provides highest degrees of freedom to solve the underdetermined system. In the case of non-circular signals, pseudo-covariances/cumulants are significant, and this additional information can further be used to increase the virtual array aperture. Herein, a framework is proposed to extend the virtual array aperture by additionally using pseudo-/non-circular cumulants along with the circular cumulants of the array output for non-circular signals. The suggested framework not only increases the resolvability but also improves the DoA estimation accuracy. With fourth-order statistics, the virtual array aperture becomes almost double, and the increment is much more with further higher order statistics. Numerical simulations demonstrate the efficacy of the claims.
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| 3. |
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| 4. |
- Wang, Jianfeng, 1984-, et al.
(författare)
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Statistical inference for block sparsity of complex-valued signals
- 2020
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Ingår i: IET Signal Processing. - : Institution of Engineering and Technology. - 1751-9675 .- 1751-9683. ; 14:3, s. 154-161
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Tidskriftsartikel (refereegranskat)abstract
- Block sparsity is an important parameter in many algorithms to successfully recover block-sparse signals under the framework of compressive sensing. However, it is often unknown and needs to be estimated. Recently there emerges a few research work about how to estimate block sparsity of real-valued signals, while there is, to the best of our knowledge, no research that has been done for complex-valued signals. In this study, we propose a method to estimate the block sparsity of complex-valued signal. Its statistical properties are obtained and verified by simulations. In addition, we demonstrate the importance of accurately estimating the block sparsity through a sensitivity analysis.
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| 5. |
- Wirfält, Petter, 1979-, et al.
(författare)
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Optimal prior knowledge-based direction of arrival estimation
- 2012
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Ingår i: IET Signal Processing. - London : Institution of Engineering and Technology. - 1751-9675 .- 1751-9683. ; 6:8, s. 731-742
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Tidskriftsartikel (refereegranskat)abstract
- In certain applications involving direction of arrival (DOA) estimation the operator may have a-priori information on some of the DOAs. This information could refer to a target known to be present at a certain position or to a reflection. In this study, the authors investigate a methodology for array processing that exploits the information on the known DOAs for estimating the unknown DOAs as accurately as possible. Algorithms are presented that can efficiently handle the case of both correlated and uncorrelated sources when the receiver is a uniform linear array. The authors find a major improvement in estimator accuracy in feasible scenarios, and they compare the estimator performance to the corresponding theoretical stochastic Cramer-Rao bounds as well as to the performance of other methods capable of exploiting such prior knowledge. In addition, real data from an ultra-sound array is applied to the investigated estimators.
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| 6. |
- Zhu, Xumin, et al.
(författare)
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Knowledge-aided adaptive beamforming
- 2008
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Ingår i: IET Signal Processing. - : Institution of Engineering and Technology (IET). - 1751-9675 .- 1751-9683. ; 2:4, s. 335-345
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Tidskriftsartikel (refereegranskat)
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