Current Issue : July-September Volume : 2022 Issue Number : 3 Articles : 5 Articles
The traditional algorithm performing direction of arrival (DOA) estimation under the background of strong interference and colored noise has the problems of low estimation accuracy and small measurement targets. Based on the construction of a fourthorder cumulant (FOC) matrix to suppress colored noise, this paper adopts the extended noise subspace (ENS) algorithm and the fixed projection blocking (FPB) algorithm to estimate the DOA of weak targets. Firstly, a FOC matrix of the received signal vector is established to curb the noise component, and the eigenvalue decomposition is performed. Then, two approaches of weak signal DOA estimation are proposed. One approach is to merge the space where the strong interference steering vector lies into the noise subspace to construct an extended noise subspace, and then, the multisignal classification (MUSIC) algorithm is used to obtain the DOA estimation of the weak signal on the basis of the extended noise subspace. Another approach is to build the orthogonal projection matrix of the interference subspace as the interference blocking matrix, and the receiving array signal is preprocessed, and on the basis of it, the eigen decomposition is performed again to obtain the DOA information of the weak signal. Both algorithms make breakthroughs in the aperture limitation of the traditional algorithm, effectively expand the aperture, and promote the accuracy of estimation. The simulation tests the effectiveness of the proposed method....
An experimental study of amplitude modulation (AM) and phase modulation (PM) noise spectra in cascaded amplifiers was carried out as a function of the number of amplification stages and the input power. Flicker and white noise contributions were determined, as well as effective noise figure (NF) from AM and PM noise spectra from small-signal to large-signal regimes. Simultaneous measurements of AM and PM noise were performed, and associated correlation was measured as a function of the offset frequency from the carrier. Measurements exhibited, in general, quite low AM–PM correlation levels both in the flicker and white noise parts of the spectrum. In some particular amplifier configurations, however, measurements showed some peaks in the correlation at some specific input power levels in the transition zone, from a quasi-linear to strong compression. The results show that the effective noise figure decreases with the number of stages for a given carrier output power level....
In digital nuclear spectroscopy, trapezoidal shaping is widely used. Compared with traditional CR-RC4 semi-Gaussian shaping, it has a better energy resolution and higher counting rates, but does not void the pulse pile-up in the case of extreme counting rates. In this paper, a new recursive algorithm is proposed that can improve the anti-pile-up ability, and is easy to implement in any DSP-based processor that is used in any digital pulse shaping filter section. The complete deduction and simulation are presented in this paper....
In this paper, we present a hardware and software platform for signal processing (SPP) in long-range, multi-spectral, electro-optical systems (MSEOS). Such systems integrate various cameras such as lowlight color, medium or long-wave-infrared thermal and short-wave-infrared cameras together with other sensors such as laser range finders, radars, GPS receivers, etc. on rotational pan-tilt positioner platforms. An SPP is designed with the main goal to control all components of an MSEOS and execute complex signal processing algorithms such as video stabilization, artificial intelligence-based target detection, target tracking, video enhancement, target illumination, multisensory image fusion, etc. Such algorithms might be very computationally demanding, so an SPP enables them to run by splitting processing tasks between a field-programmable gate array (FPGA) unit, a multicore microprocessor (MCuP) and a graphic processing unit (GPU). Additionally, multiple SPPs can be linked together via an internal Gbps Ethernet-based network to balance the processing load. A detailed description of the SPP system and experimental results of workloads for typical algorithms on demonstrational MSEOS are given. Finally, we give remarks regarding upgrading SPPs as novel FPGAs, MCuPs and GPUs become available....
With the rapid development of China’s market economy and the continuous deepening of system reforms, enterprises are also facing more problems while facing greater challenges. In order to deeply explore the role of intelligent signal processing in the development of enterprises in the context of 5G technology, this article uses data collection methods, questionnaire methods, and model building methods to collect data and analyze economic and institutional factors in the development of enterprises. The algorithm has been streamlined. First the impact of environmental factors in sustainable economic development is studied. The results show that, in the optimal economic growth plan, the optimal GDP is 27.65 trillion yuan, and the proportions of the three industries are 8.8%, 38.5%, and 49.7%, respectively; in the optimal pollution emission plan, the proportions of the three industries are 11.8%, 20.15%, and 65.5% respectively. In the neutral plan, the optimal GDP is 27.89 trillion yuan, and the proportions of the three industries are 8.5%, 39.7%, and 49.8%, respectively. This shows that, under the goal of pursuing the optimal environment, the economy can still be maintained. Further the advantages of the system in this article are discussed by analyzing the degree of synergy between them and the continuous growth of the enterprise; we can find that, from 2001 to 2006, the degree of synergy between enterprise technological innovation and institutional innovation has been continuously improved, and it has increased by 332.7% during this period, which shows that technological innovation, institutional innovation, and enterprise growth are coordinated development. It was basically realized that, starting from the intelligent signal processing technology, the economic model and innovation system that can develop together with the environment have been designed....
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