Frequency: Quarterly E- ISSN: 2277-6435 P- ISSN: Awaited Abstracted/ Indexed in: Ulrich's International Periodical Directory, Google Scholar, SCIRUS, Genamics JournalSeek, EBSCO Information Services
"Inventi Impact: Signal Processing" is a peer reviewed journal dedicated to the advancements in the fields of analogue and digital signal processing. Areas covered include stochastic processes, spectral analysis and signal processing related to biomedical and geophysical applications, besides others.
This paper presents an iterative algorithm for the synthesis of the three-dimensional\n(3D) radiation pattern generated by an antenna array of arbitrary geometry. The algorithm is\nconceived to operate in fifth-generation (5G) millimeter-wave scenarios, thus enabling the support of\nmulti-user mobile streaming and massive peer-to-peer communications, which require the possibility\nto synthesize 3D patterns with wide null regions and multiple main beams. Moreover, the proposed\nsolution adopts a phase-only control approach to reduce the complexity of the feeding network\nand is characterized by a low computational cost, thanks to the closed-form expressions derived\nto estimate the phase of each element at the generic iteration. These expressions are obtained from\nthe minimization of a weighted cost function that includes all the necessary constraints. To finally\ncheck its versatility in a 5G environment, the developed method is validated by numerical examples\ninvolving planar and conformal arrays, considering desired patterns with different numbers of main\nbeams and nulls....
This article introduces a novel approach for finding a rigid transformation that coarsely aligns two 3D point clouds.\r\nThe algorithm performs an iterative comparison between 2D descriptors by using a purpose-designed similarity\r\nmeasure in order to find correspondences between two 3D point clouds sensed from different positions of a freeform\r\nobject. The descriptors (named with the acronym CIRCON) represent an ordered set of radial contours that\r\nare extracted around an interest-point within the point cloud. The search for correspondences is done iteratively,\r\nfollowing a cell distribution that allows the algorithm to converge toward a candidate point. Using a single\r\ncorrespondence an initial estimation of the Euclidean transformation is computed and later refined by means of a\r\nmultiresolution approach. This coarse alignment algorithm can be used for 3D modeling and object manipulation\r\ntasks such as ââ?¬Å?Bin Pickingââ?¬Â when free-form objects are partially occluded or present symmetries...
In this paper, a second-order asynchronous delta-sigma modulator (ADSM) is proposed\nbased on the active-RCintegrators. The ADSM is implemented in the 0.18....................
Video summarization aims to provide a compact video representation while preserving the essential activities of the\noriginal video. Most existing video summarization approaches relay on identifying important frames and optimizing\ntarget energy by a global optimum solution. But global optimum may fail to express continuous action or realistically\nvalidate how human beings perceive a story. In this paper, we present a bottom-up approach named clip growing for\nvideo summarization, which allows users to customize the quality of the video summaries. The proposed approach\nfirstly uses clustering to oversegment video frames into video clips based on their similarity and proximity.\nSimultaneously, the importance of frames and clips is evaluated from their corresponding dissimilarity and\nrepresentativeness. Then, video clips and frames are gradually selected according to their energy rank, until reaching\nthe target length. Experimental results on SumMe dataset show that our algorithm can produce promising results\ncompared to existing algorithms. Several video summarizations results are presented in supplementary material....
The application of device-to-device (D2D) communication in cellular networks can significantly improve the\nefficiency of spectrum utilization, which benefits local area cooperative services. On the other hand, network coding\ncan realize more efficient cooperation among cellular users. Thus, it is natural to combine network coding with D2D\ncommunication in order to further increase the system sum rate. In this paper, a coalitional graph game framework is\nproposed to jointly accomplish resource allocation and relay selection, two challenging problems in network\ncoding-aided D2D communication networks. It is shown that this framework can model D2D communication\ncombined with various network coding schemes. Based on the coalitional graph game framework, a distributed\nalgorithm with low computational complexity is proposed to solve the formulated problem for physical layer network\ncoding-aided D2D communication. Finally, the performance of the proposed transmission scheme is evaluated\nthrough extensive simulations....
Ultrashort pulse (USP) signal with high peak power is also called ultrawideband signal, which has a broad application prospect in radar detection and electronic countermeasures and other fields. In this paper, an acquisition device is proposed to obtain the USP signal with ultrahigh compression efficiency (CE) and ultrahigh power compression gain (PCG). The long input pulse with a time length of μs level can be compressed to a narrow pulse with a pulse width of 450 ps level (2.6–3.9 GHz) by using the proposed USP acquisition device. Under the condition without loss, the CE of the USP acquisition device can reach up to 98% according to the simulated results. In the simulation, if the material of the acquisition device is set to copper material, then the CE has some reduction due to conductor loss. In order to demonstrate the effectiveness of the proposed USP acquisition device, a USP acquisition device is established and measured. According to the measurement results, a measured PCG of 27 dB is achieved and the pulse width is approximately 460 ps. The peak power of the output USP signal reaches to 100kW under the condition of input pulse with a power of 200 W....
The fractional Fourier transform (FRFT) method has emerged in response to the demand for high-performance time-frequency\nprocessing technology. Next, the weighted fractional Fourier transform (WFRFT) method was developed, especially the\nsingle-parameter 4-weighted fractional Fourier transform (SP-4-WFRFT), which is most suitable for applications in digital\ncommunication systems. Therefore, in receiving systems, research on the scanningmethod of transformation order has also become\nthe focus of research under the condition of unknown transformation order. However, in the process of inverse transformation,\nthere are many problems, such as long scanning times and slow scanning speed. Thus, to improve the characteristics of a digital\ncommunication system based on SP-4-WFRFT, a cross-hierarchical scanning (CHS) method is established. A large number of test\nresults show that the CHS method can achieve fast recovery of data and estimation of transformation order....
A feature extraction algorithm is introduced for face recognition, which efficiently exploits the local spatial variations in a face\r\nimage utilizing curvelet transform. Although multi-resolution ideas have been profusely employed for addressing face recognition\r\nproblems, theoretical studies indicate that digital curvelet transform is an even better method due to its directional properties.\r\nInstead of considering the entire face image, an entropy-based local band selection criterion is developed for feature extraction,\r\nwhich selects high-informative horizontal bands from the face image. These bands are segmented into several small spatial modules\r\nto capture the local spatial variations precisely. The effect of modularization in terms of the entropy content of the face images has\r\nbeen investigated. Dominant curvelet transform coefficients corresponding to each local region residing inside the horizontal\r\nbands are selected, based on the proposed threshold criterion, as features, which not only drastically reduces the feature dimension\r\nbut also provides high within-class compactness and high between-class separability. A principal component analysis is performed\r\nto further reduce the dimensionality of the feature space. Extensive experimentation is carried out upon standard face databases\r\nand a very high degree of recognition accuracy is achieved even with a simple Euclidean distance based classifie...
In order to solve the problem of detecting a BOC signal, which uses a long-period pseudo random sequence, an algorithm is\npresented based on quadrature channel correlation. The quadrature channel correlation method eliminates the autocorrelation\ncomponent of the carrier wave, allowing for the extraction of the absolute autocorrelation peaks of the BOC sequence. If the same\nlag difference and height difference exist for the adjacent peaks, the BOC signal can be detected effectively using a statistical analysis\nof themultiple autocorrelation peaks.Thesimulation results show that the interference of the carrier wave component is eliminated\nand the autocorrelation peaks of the BOC sequence are obtained effectively without demodulation.The BOC signal can be detected\neffectively when the SNR is greater than âË?â??12 dB.The detection ability can be improved further by increasing the number of sampling\npoints. The higher the ratio of the square wave subcarrier speed to the pseudo random sequence speed is, the greater the detection\nability is with a lower SNR.The algorithm presented in this paper is superior to the algorithm based on the spectral correlation....
This paper addresses distributed parameter coordination methods for wireless communication systems. This proposes\r\na method based on a message-passing algorithm, namely min-sum algorithm, on factor graphs for the application of\r\nprecoder selection. Two particular examples of precoder selection are considered: transmit antenna selection and\r\nbeam selection. Evaluations on the potential of such an approach in a wireless communication network are provided,\r\nand its performance and convergence properties are compared with those of a baseline selfish/greedy approach.\r\nSimulation results for the precoder selection examples are presented and discussed, which show that the\r\ngraph-based technique generally obtains gain in sum rate over the greedy approach at the cost of a larger message\r\nsize. Besides, the proposed method usually reaches the global optima in an efficient manner. Methods of improving\r\nthe rate of convergence of the graph-based distributed coordination technique and reducing its associated message\r\nsize are therefore important topics for wireless communication networks....
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