Space-Time Adaptive processing is a commonly used technique to mitigate ground clutter reflections from an airborne radar system. It estimates a covariance matrix based on spatial and temporal information, and the est...
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ISBN:
(纸本)9781728119465
Space-Time Adaptive processing is a commonly used technique to mitigate ground clutter reflections from an airborne radar system. It estimates a covariance matrix based on spatial and temporal information, and the estimate is thereafter used to suppress the ground clutter. In a side-looking monostatic radar system, the estimate is rather straight forward based on radar observations. However, in this paper, we consider bistatic systems where the power of adaptivity is limited due to nonstationarity of the ground clutter reflections over the range dimension. To overcome this, scenario dependent transformations are commonly used when forming the sample covariance matrix. In this contribution we instead investigate a detector where the clutter covariance matrix is determined from the geometry of the bistatic scenario. Using a Monte-Carlo simulation, we investigate how sensitive the detector is to errors in the assumed geometry, and compare this with state-of-the-art adaptive methods. The results indicates that a good clutter rejection is obtained for errors of order 10(3) m for assumed transmitter position and 10(0) km/h for assumed transmitter velocity.
This work studies the effects of different waveform designs on the clutter removal and target localization in through-the-wall radar (TWR) system. To removal the wall clutter, its low-rank property is utilized, wherea...
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ISBN:
(纸本)9781728119465
This work studies the effects of different waveform designs on the clutter removal and target localization in through-the-wall radar (TWR) system. To removal the wall clutter, its low-rank property is utilized, whereas the sparse property of the target returns is exploited to perform target reconstruction. As a result, a joint low-rank and sparse model is developed where alternating direction method of multipliers (ADMM) is utilized to solve the corresponding optimization. Moreover, to demonstrate the performances of different waveforms, three well-known signals including mono-frequency, stepped-frequency, and frequency-modulated continuous-wave (FMCW) waveforms have been selected for transmit. The experimental results show advantages and disadvantages of each waveform.
In this paper, a reduced-rank direction-of-arrival (DOA) estimation algorithm for incoherently distributed (ID) noncircular sources based on a uniform linear array (ULA) is proposed. First the noncircularity property ...
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ISBN:
(数字)9781728119465
ISBN:
(纸本)9781728119465
In this paper, a reduced-rank direction-of-arrival (DOA) estimation algorithm for incoherently distributed (ID) noncircular sources based on a uniform linear array (ULA) is proposed. First the noncircularity property of the signal is utilized to establish an extended generalized array manifold (GAM) model based on the first-order Taylor series approximation. Then, the central DOA of source signals is obtained based on the generalized shift invariance property of the array manifold and the reduced-rank principle. Compared with the algorithm without exploiting the noncircularity information, the proposed algorithm can achieve a higher accuracy and handle more sources. Simulation results are provided to demonstrate the performance of the proposed algorithm.
According to the investigation of automation test task in the construction of new energy transformer substation, it is found that the automatic data channel of OPGW fibre-optical high-voltage line is delayed due to va...
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According to the investigation of automation test task in the construction of new energy transformer substation, it is found that the automatic data channel of OPGW fibre-optical high-voltage line is delayed due to various reasons, which seriously affects the project grid-connected power generation. Therefore, the automation test before the project is put into operation must look for a reliable wireless data channel to replace the formal fiber-optic communication channel, in order to complete the relevant electrical automation test tasks. According to the characteristics and advantages of UHF wireless technology, this paper studies deeply the realization method of communication link based on UHF wireless technology, and fully demonstrates the flexibility of UHF wireless technology as an advance debugging channel in transformer substation construction, it has a positive development prospect.
CMOS image sensors have gained popularity due to low power consumption, high speed and their ability to scale to smaller sizes. These factors can further be improved by either improving the circuitry of the imager or ...
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ISBN:
(纸本)9781665419130
CMOS image sensors have gained popularity due to low power consumption, high speed and their ability to scale to smaller sizes. These factors can further be improved by either improving the circuitry of the imager or by enhancing the processing capabilities of the entire imaging system through on-chip processing of the pixel information. One such improvement is to read only a small fraction of the pixel array information and reconstruct the original information from it. The on-chip prediction of the unread pixels to reconstruct the acquired image is still an open problem. Here we propose a solution to the problem which relies on on-chip implementation of simple convolutional neural network (CNN) for pixel prediction and image reconstruction. The system strives to selectively read only a minimal number of pixels (10% to 15%), while skipping the rest. This attributes to a considerable saving on power and checks the issue of latency at the ADC. This selective process in reading of only few pixels generates a sparse image signal. The proposed network is trained to reconstruct the estimation of the actual image from the sparse set. The hardware accelerator that incorporates the CNN model also considers hardware limitations and constraints such as power consumption and latency. The PSNR achieved for the SiDCNet variant with SqueezeNet achieves for test images is similar to 30 dB for 85% of pixels skipped, and the quantized model does not lose much in PSNR.
The output signal components of the sensitive end of micro-electro-mechanical system (MEMS) gyroscope are complex, and the design error of the back-end demodulation circuit can greatly affect the detection accuracy of...
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The shape of the long line array is required to correct signalprocessing data and locate underwater targets precisely. In this paper, the warping transform form with waveguide invariant (β) is adopted to extract the...
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Wide scale deployment of wireless devices is making the spectrum a scarce resource. Joint communication and sensing (JC&S) and in-band full duplex (IBFD) communications provide opportunities of spectrum reuse. IBF...
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Wide scale deployment of wireless devices is making the spectrum a scarce resource. Joint communication and sensing (JC&S) and in-band full duplex (IBFD) communications provide opportunities of spectrum reuse. IBFD communication hardware requires high transmitter-to-receiver (TRx) isolation, making it shareable and reusable with mono-static continuous wave radar in JC&S context. On the other hand, design and development of beamforming phased arrays, required for communication coverage and radar spatial filtering, becomes challenging when a high TRx isolation assurance is required. This paper presents a solution in the form of antenna-duplexed passive beamformer usable for IBFD communication and mono-static continuous wave radars, mitigating two key challenges/requirements of JC&S hardware reuse in co-design approach - TRx isolation and beamforming capability. A beamformer using Butler matrix and a planar quasi-circulator are designed and optimized for X-band (centered at 10 GHz) providing up to 40 dB transmitter leakage suppression using primarily passive circuits.
The proceedings contain 162 papers. The topics discussed include: 2D DOA estimation for uniform rectangular array with one-bit measurement;3D parametric channel estimation for multi-user massive-MIMO OFDM systems;a bl...
ISBN:
(纸本)9781728119465
The proceedings contain 162 papers. The topics discussed include: 2D DOA estimation for uniform rectangular array with one-bit measurement;3D parametric channel estimation for multi-user massive-MIMO OFDM systems;a blind direction of arrival and mutual coupling estimation scheme for nested array;a compressive sensing approach for single-snapshot adaptive beamforming;a general ESPRIT method for noncircularity-based incoherently distributed sources;a general framework for the robustness of structured difference coarrays to element failures;a gridless method for DOA estimation under the coexistence of mutual coupling and unknown nonuniform noise;a gridless wideband doa estimation based on atomic norm minimization;a new hyperspectral compressed sensing method for efficient satellite communications;a note on the maximum number of sources in DOA estimation by mode;and a novel NLOS target localization method with a synthetic bistatic MMW radar.
As a kind of hypercomplex number with strict orthogonality, quaternion can bring many benefits when applied to the signalprocessing for electromagnetic vector sensorarray, but the quaternion model can deal two-compo...
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