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Super-resolution enhancement is a kind of promising approach to enhance the spatial resolution of images. To super-resolve a satisfying result, regularization term design and blur kernel estimation are two important aspects which need to be carefully considered. In this paper, we propose a robust regularized super-resolution reconstruction approach based on two sparsity properties to deal with these...
In mixed-resolution multiview setups, spatially neighboring high-resolution views can be used to increase the image quality of an intermediate low-resolution camera perspective. By utilizing corresponding depth data, high-frequency information can be projected from the reference perspectives onto the image plane of the low-resolution view, creating the desired super-resolved image. In this context,...
This paper focuses on performance enhancement for stand-alone Global Navigation Satellite System (GNSS) positioning. To speed up the realization of satellite position, a novel technique is proposed for GNSS satellite orbit fast fitting, which contributes to the acquisition of GNSS satellite signal deeply. The ephemeris orbit model is imminent by different fitting algorithms and polynomial interpolation...
In this paper, we propose an up-sampling technique in which DCT and Zernike moments (ZMs) are used in hybrid mode to up-sample the images that are down-sampled in DCT domain. DCT-based up-sampling techniques are very effective and simple for up-sampling in DCT domain. However, being discrete and finite, they do not offer any direct way to recover missing details (for instance, substitution of high...
This paper proposes an efficient channel estimation method based on comb pilots. This method is used for OFDM system under time-variant conditions. When under the high speed mobile channel, Doppler frequency shift will cause serious inter-carrier interference (ICI). As it is known, the ICI is manifest as noise in many cases. Therefore, a low pass filter can be used in the transform domain to reduce...
With their greatly reduced sizes, low development cost and rapid construction times, CubeSats have emerged as a platform of intense interest for a wide range of applications, including remote sensing. However, due to their compact form factor, performance tradeoffs relative to larger existing platforms have been encountered. Of specific interest in this paper are data processing challenges associated...
Single-sensor color cameras, which classically use a color filter array (CFA) to sample RGB channels, have recently been extended to the multispectral domain. To sample more than three wavelength bands, such systems use a multispectral filter array (MSFA) that provides a raw image in which a single channel level is available at each pixel. A demosaicing procedure is then needed to estimate a multispectral...
The improvement in Maritime Situational Awareness (MSA), or the capability of understanding events, circumstances and activities within and impacting the maritime environment, is nowadays of paramount importance for safety and security. Enhancing coverage of existing technologies such as Automatic Identification System (AIS) provides the possibility to integrate and enrich services and information...
A combination of spatial modulation and orthogonal frequency division multiplexing (SM-OFDM) has been recently proposed for multicarrier systems while assuming the perfect channel state information (P-CSI) available at the receiver. But, in practical scenarios, the estimation of CSI is crucial in order to detect the transmitted data coherently. In this work1, a new frame structure and pilot symbol...
This paper presents a novel method for generating a secret key to augment the security of spread spectrum systems. The proposed key generation takes advantage of the channel reciprocity exhibited between two communicating parties. We validate the key generation aspect of our system by using real-world measurements. We note that the strongest path in the channel impulse response can be the main source...
In order to provide a reliable reception and decrease the packet retransmission, the wireless communication system should guaranty the accuracy of channel estimation. This implies that the channel estimation mean-square error (MSE) of the mobile terminals with various speeds should remain lower than a threshold. This usually causes higher pilot overhead in terms of more bandwidth and transmit power...
The estimation of the frequency of a complex exponential sinusoid that is corrupted by random noise is fundamental in the domain of signal processing, as it has a variety of application in many areas. In this study, we presented a frequency estimator in the frequency domain of a complex signal. The estimator is composed of two steps: a standard maximum bin coarse search and a fine search. The fine...
This paper proposes an efficient channel parameters estimation design for Single Carrier Frequency Domain Equalization (SC-FDE) in High Frequency (HF) wireless communications. This design is implemented to improve the performance of existing channel estimation by integrating and optimizing traditional channel statistical characteristics estimation. Based on the Synchronization Training Sequences (STS)...
Recently, microwave remote sensing has been used for observation of the global environment extensively. There are many techniques in the microwave remote sensing. Among them, SAR (Synthetic Aperture Radar) Tomography is one of the emerging technique that can realize three dimensional imaging, by using multiple flight paths. The data pixels in each SAR image obtained at the slightly different paths...
IEEE802.11ac is a 5GHz based very high throughput (VHT) wireless local area network (WLAN) standard with superior performance at channel capacity and transmission rate due to accurate channel estimation. Traditionally, the channel state information (CSI) of data field is obtained via training sequence in time domain such as VHI-LTF, which performs weakly in non-flat and slow fading channel. This paper...
Frame Rate Up Conversion (FRUC) makes video playback smoother and more natural to the human eye by inserting interleave frames between existing frames. Quality of existing FRUC has had issues of ghosting and blurring effects caused by interpolation based on blending function. Existing motion estimation method produces inaccurate motion vectors, which are the culprit of low quality frames when motion-compensated...
Small cells deployed over the existing macrocell network reduce the access distance and thus offer an energy-efficient solution to provide high data rate coverage. However, dense deployment of small cells may cause energy waste under low load conditions. To cope with this issue, power saving techniques for small cell networks need to be carefully investigated. Invoking a sleep mode is one of the most...
Weeds are among the most significant and costly environmental threats in Australian agriculture. The distribution, size, density and species of weeds are often heterogeneous in cropping lands. Instead of uniformly spray the same type of herbicide to a whole farm land, using weed maps to do selective spray can reduce herbicide usage and therefore can reduce the serious problems of herbicide resistance,...
The research problem of the parameter estimation of multiple superimposed damped complex exponentials in noise is of significant importance in many engineering and science applications. In this paper, we propose a simple yet accurate estimator to address the problem. By combining an efficient windowed frequency and damping estimator for a single component with an iterative leakage subtraction scheme,...
In this paper, we propose a novel motion estimation algorithm for true motion estimation. After obtaining an initial motion vector map through hierarchical block matching algorithm with distance constraints, we classify the motion vectors based on residual energy map. With block and edge information, the motion vector map can get updated iteratively until it reaches the predefined condition. The experiment...
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