In this article,a single-board integrated millimeter-wave(mm-Wave)asymmetric full-digital beamforming(AFDBF)array is developed for beyond-fifth-generation(B5G)and sixth-generation(6G)communications.The proposed integr...In this article,a single-board integrated millimeter-wave(mm-Wave)asymmetric full-digital beamforming(AFDBF)array is developed for beyond-fifth-generation(B5G)and sixth-generation(6G)communications.The proposed integrated array effectively addresses the challenge of arranging a large number of ports in a full-digital array by designing vertical connections in a three-dimensional space and successfully integrating full-digital transmitting(Tx)and receiving(Rx)arrays independently in a single board.Unlike the traditional symmetric array,the proposed asymmetric array is composed of an 8×8 Tx array arranged in a square shape and an 8+8 Rx array arranged in an L shape.The center-to-center distance between two adjacent elements is 0.54k0 for both the Tx and Rx arrays,where k0 is the free-space wavelength at 27 GHz.The proposed AFDBF array possesses a more compact structure and lower system hardware cost and power consumption compared with conventional brick-type full-digital arrays.In addition,the energy efficiency of the proposed AFDBF array outperforms that of a hybrid beamforming array.The measurement results indicate that the operating frequency band of the proposed array is 24.25–29.50 GHz.An eight-element linear array within the Tx array can achieve a scanning angle ranging from-47°to+47°in both the azimuth and the elevation planes,and the measured scanning range of each eight-element Rx array is–45°to+45°.The measured maximum effective isotropic radiated power(EIRP)of the eight-element Tx array is 43.2 dBm at 28.0 GHz(considering the saturation point).Furthermore,the measured error vector magnitude(EVM)is less than 3%when 64-quadrature amplitude modulation(QAM)waveforms are used.展开更多
We present a digital micromirror device(DMD) based superpixel method for focusing light through scattering media by modulating the complex field of incident light. Firstly, we numerically and experimentally investig...We present a digital micromirror device(DMD) based superpixel method for focusing light through scattering media by modulating the complex field of incident light. Firstly, we numerically and experimentally investigate focusing light through a scattering sample using the superpixel methods with different target complex fields.Then, single-point and multiple-point focusing experiments are performed using this superpixel-based complex modulation method. In our experiment, up to 71.5% relative enhancement is realized. The use of the DMDbased superpixel method for the control of the complex field of incident light opens an avenue to improve the enhancement of focusing light through scattering media.展开更多
Over the past decade, open-source software use has grown. Today, many companies including Google, Microsoft, Meta, RedHat, MongoDB, and Apache are major participants of open-source contributions. With the increased us...Over the past decade, open-source software use has grown. Today, many companies including Google, Microsoft, Meta, RedHat, MongoDB, and Apache are major participants of open-source contributions. With the increased use of open-source software or integration of open-source software into custom-developed software, the quality of this software component increases in importance. This study examined a sample of open-source applications from GitHub. Static software analytics were conducted, and each application was classified for its risk level. In the analyzed applications, it was found that 90% of the applications were classified as low risk or moderate low risk indicating a high level of quality for open-source applications.展开更多
The demand for quality software expands as the business environment grows internationally. Common to all software development methodologies is a design phase that focuses on the physical software model. Design criteri...The demand for quality software expands as the business environment grows internationally. Common to all software development methodologies is a design phase that focuses on the physical software model. Design criteria used to evaluate these models are important for refinement and improvement. The purpose of this research is to apply transformations of McCabe’s cyclomatic complexity as a means for improving software design and assessing risks within a design. In this research, two metrics, the management (<em>C<sub>MGT</sub></em>) and maintenance (<em>C<sub>MN</sub></em>) coefficients are introduced, and they are used to address the architectural, size, and quality dimensions of a software design.展开更多
This paper applies software analytics to open source code. Open-source software gives both individuals and businesses the flexibility to work with different parts of available code to modify it or incorporate it into ...This paper applies software analytics to open source code. Open-source software gives both individuals and businesses the flexibility to work with different parts of available code to modify it or incorporate it into their own project. The open source software market is growing. Major companies such as AWS, Facebook, Google, IBM, Microsoft, Netflix, SAP, Cisco, Intel, and Tesla have joined the open source software community. In this study, a sample of 40 open source applications was selected. Traditional McCabe software metrics including cyclomatic and essential complexities were examined. An analytical comparison of this set of metrics and derived metrics for high risk software was utilized as a basis for addressing risk management in the adoption and integration decisions of open source software. From this comparison, refinements were added, and contemporary concepts of design and data metrics derived from cyclomatic complexity were integrated into a classification scheme for software quality. It was found that 84% of the sample open source applications were classified as moderate low risk or low risk indicating that open source software exhibits low risk characteristics. The 40 open source applications were the base data for the model resulting in a technique which is applicable to any open source code regardless of functionality, language, or size.展开更多
Signal structure design is an important part of satellite navigation system research,which directly affects navigation performance.Signal performance parameters are analyzed and performances of BPSK modulated signals ...Signal structure design is an important part of satellite navigation system research,which directly affects navigation performance.Signal performance parameters are analyzed and performances of BPSK modulated signals and BOC modulated signals are compared.Aiming at requirements of high navigation precision and high anti-jamming ability,a new navigation signal structure based on complex carrier modulation is proposed and performances of the signal are researched with different parameters.A synchronization algorithm is put forward according to the signal characteristics,and the synchronization performance is qualitatively analyzed.Next,the applications of the complex carrier modulated signal are discussed,which include anti-jamming,navigation enhancement,power combing and so on.Simulations and analysis show that the proposed navigation signal structure based on complex carrier modulation has good navigation capabilities and anti-jamming abilities,which deserves further study.展开更多
基金supported by the National Key Research and Development Program of China(2020YFB1804900 and 2022YFE0210900)the Fundamental Research Funds for the Central Universities(2242022k60008 and 2242022k30003)+2 种基金the National Natural Science Foundation of China(62301152 and 61627801)the Youth Talent Promotion Foundation of Jiangsu Science and Technology Association(TJ-2023-074)the Startup Research Fund of Southeast University(RF1028623286).
文摘In this article,a single-board integrated millimeter-wave(mm-Wave)asymmetric full-digital beamforming(AFDBF)array is developed for beyond-fifth-generation(B5G)and sixth-generation(6G)communications.The proposed integrated array effectively addresses the challenge of arranging a large number of ports in a full-digital array by designing vertical connections in a three-dimensional space and successfully integrating full-digital transmitting(Tx)and receiving(Rx)arrays independently in a single board.Unlike the traditional symmetric array,the proposed asymmetric array is composed of an 8×8 Tx array arranged in a square shape and an 8+8 Rx array arranged in an L shape.The center-to-center distance between two adjacent elements is 0.54k0 for both the Tx and Rx arrays,where k0 is the free-space wavelength at 27 GHz.The proposed AFDBF array possesses a more compact structure and lower system hardware cost and power consumption compared with conventional brick-type full-digital arrays.In addition,the energy efficiency of the proposed AFDBF array outperforms that of a hybrid beamforming array.The measurement results indicate that the operating frequency band of the proposed array is 24.25–29.50 GHz.An eight-element linear array within the Tx array can achieve a scanning angle ranging from-47°to+47°in both the azimuth and the elevation planes,and the measured scanning range of each eight-element Rx array is–45°to+45°.The measured maximum effective isotropic radiated power(EIRP)of the eight-element Tx array is 43.2 dBm at 28.0 GHz(considering the saturation point).Furthermore,the measured error vector magnitude(EVM)is less than 3%when 64-quadrature amplitude modulation(QAM)waveforms are used.
基金Supported by the Natural Science Foundation of Beijing under Grant Nos 2162033 and 7182091the National Natural Science Foundation of China under Grant No 21627813
文摘We present a digital micromirror device(DMD) based superpixel method for focusing light through scattering media by modulating the complex field of incident light. Firstly, we numerically and experimentally investigate focusing light through a scattering sample using the superpixel methods with different target complex fields.Then, single-point and multiple-point focusing experiments are performed using this superpixel-based complex modulation method. In our experiment, up to 71.5% relative enhancement is realized. The use of the DMDbased superpixel method for the control of the complex field of incident light opens an avenue to improve the enhancement of focusing light through scattering media.
文摘Over the past decade, open-source software use has grown. Today, many companies including Google, Microsoft, Meta, RedHat, MongoDB, and Apache are major participants of open-source contributions. With the increased use of open-source software or integration of open-source software into custom-developed software, the quality of this software component increases in importance. This study examined a sample of open-source applications from GitHub. Static software analytics were conducted, and each application was classified for its risk level. In the analyzed applications, it was found that 90% of the applications were classified as low risk or moderate low risk indicating a high level of quality for open-source applications.
文摘The demand for quality software expands as the business environment grows internationally. Common to all software development methodologies is a design phase that focuses on the physical software model. Design criteria used to evaluate these models are important for refinement and improvement. The purpose of this research is to apply transformations of McCabe’s cyclomatic complexity as a means for improving software design and assessing risks within a design. In this research, two metrics, the management (<em>C<sub>MGT</sub></em>) and maintenance (<em>C<sub>MN</sub></em>) coefficients are introduced, and they are used to address the architectural, size, and quality dimensions of a software design.
文摘This paper applies software analytics to open source code. Open-source software gives both individuals and businesses the flexibility to work with different parts of available code to modify it or incorporate it into their own project. The open source software market is growing. Major companies such as AWS, Facebook, Google, IBM, Microsoft, Netflix, SAP, Cisco, Intel, and Tesla have joined the open source software community. In this study, a sample of 40 open source applications was selected. Traditional McCabe software metrics including cyclomatic and essential complexities were examined. An analytical comparison of this set of metrics and derived metrics for high risk software was utilized as a basis for addressing risk management in the adoption and integration decisions of open source software. From this comparison, refinements were added, and contemporary concepts of design and data metrics derived from cyclomatic complexity were integrated into a classification scheme for software quality. It was found that 84% of the sample open source applications were classified as moderate low risk or low risk indicating that open source software exhibits low risk characteristics. The 40 open source applications were the base data for the model resulting in a technique which is applicable to any open source code regardless of functionality, language, or size.
文摘Signal structure design is an important part of satellite navigation system research,which directly affects navigation performance.Signal performance parameters are analyzed and performances of BPSK modulated signals and BOC modulated signals are compared.Aiming at requirements of high navigation precision and high anti-jamming ability,a new navigation signal structure based on complex carrier modulation is proposed and performances of the signal are researched with different parameters.A synchronization algorithm is put forward according to the signal characteristics,and the synchronization performance is qualitatively analyzed.Next,the applications of the complex carrier modulated signal are discussed,which include anti-jamming,navigation enhancement,power combing and so on.Simulations and analysis show that the proposed navigation signal structure based on complex carrier modulation has good navigation capabilities and anti-jamming abilities,which deserves further study.