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The speed of the target can be estimated by the sound pressure cross-correlation of the line spectrum of the moving target at different time intervals. However, a slight deviation of the line spectrum has a significant influence on the estimated result. In this paper this phenomenon is analyzed from the theory, then the speed of the target is estimated when the line spectrum is biased. Experimental...
Considering a small-scale fading environment in a dense random wireless network, we investigate the impact of the carrier-sensing threshold on the link performance under the premise of a fixed carrier-sensing range. At first, we assume a close transmitter-receiver distance and model the network nodes as a homogeneous Poisson point process (PPP). Then we present a simple analysis model of the conditional...
In this paper, we propose novel user clustering schemes for downlink non-orthogonal multiple access (NOMA) system, where an N-antenna base station (BS) selects and serves 2N users from K single antenna user equipments (UEs) (K ≥ 2N and K is even). In particular, we propose a signal difference and alignment (SDA) framework to achieve fair and spectral efficient user clustering for NOMA with flexible...
Due to dense small cells deployment in a heterogeneous network, the backhaul links among the small cells and macro cell are band-limited when they share the same spectrum with the user equipments. To mitigate the intra- and inter-cell interference caused by the band-limited backhaul, we propose a recursive estimation-based zero-forcing beamforming (RE-ZFBF) scheme. Based on initial values obtained...
How to effectively learn temporal variation of target appearance, to exclude the interference of cluttered background, while maintaining real-time response, is an essential problem of visual object tracking. Recently, Siamese networks have shown great potentials of matching based trackers in achieving balanced accuracy and beyond realtime speed. However, they still have a big gap to classification...
This paper presents two constructions of Gaussian integer Z-periodic complementary sequence (ZPCS) sets. Construction I employs a ZPCS set as the original sequence set, however, the parameters of the resultant sequence sets cannot be flexibly chosen. Construction II generates Gaussian integer ZPCS sets using an orthogonal matrix, the ZCZ length and the flock size have flexible choices. The sequences...
Plane wave methods for ultrafast ultrasound imaging suffer from a low signal to noise ratio (SNR) and a limited field of view at greater imaging depths. Imaging using multiple focused coded beams in parallel is one strategy for high speed imaging that may improve on these limitations. However, the SNR and resolution of this strategy are degraded by the interference between the beams transmitted in...
Received Signal Strength Indicator (RSSI) is simplest among various indoor localization methods. The main drawback is requiring a training phase to build fingerprints database, which is time consuming and sensitive to changes of test environment. Time based approaches such as Time of Arrival (ToA) and Time Difference of Arrival (TDoA) achieve better performance with some hardware expenditure, while...
This paper presents a new adaptation of Zadoff-Chu sequences for the purpose of range estimation and movement tracking. The proposed method uses Zadoff-Chu sequences utilizing a wideband ultrasonic signal to estimate the range between two devices with very high accuracy and high update rate. This range estimation method is based on time of flight (TOF) estimation using cyclic cross correlation. The...
This paper presents a filter for exploiting time-varying cyclostationary statistics. The motivating example is designing redundancies into an OFDM signal to reject in-band, strong, wideband interference. Combining the filter with error correcting codes gives a 10 dB gain over LDPC codes and more than a 1000x reduction in BER. This allows the creation of multicarrier waveforms that are robust, reliable...
We study the problem of interference mitigation in a phased array, where a subset containing k out of a total of N receivers creates a virtual spatial null for an incoming interference. The signal-of-interest and interference are represented by their corresponding steering vectors, and an optimum subarray is chosen such that the two vectors are as orthogonal as possible. This optimization is a binary...
Exponentially increasing demands for higher data rates and quality of service cannot be satisfied by delivering more power as higher power levels may reduce Signal-to-Interference-plus-Noise Ratio (SINR) with negative impact on overall system performances. Simultaneously, the continuous shrinking in transistors size for denser circuits integration, following Moore's law, will be constrained by the...
Efficient estimation of depth from pairs of stereo images is one of the core problems in computer vision. We efficiently solve the specialized problem of stereo matching under active illumination using a new learning-based algorithm. This type of active stereo i.e. stereo matching where scene texture is augmented by an active light projector is proving compelling for designing depth cameras, largely...
In this paper, we propose a joint analog-digital (AD) beamforming scheme that exploits the mutual coupling effect to further improve the performance of multi-user multiple-input single-output (MU-MISO) systems. We firstly propose a joint AD scheme by iteratively optimizing the beamforming vectors in the digital domain and the load impedances of each antenna element in the analog domain. We further...
An accurate statistical picture of nonlinear noise in WDM systems deployed over non-dispersion-managed, lumped-amplification optical links is obtained via simulations. We separately assess intra- and inter-channel effects, allowing comparison with analytical models. Our method also discerns between additive and phase components of the noise.
In wireless communication, heterogeneous technologies such as WiFi, ZigBee and BlueTooth operate in the same ISM band.With the exponential growth in the number of wireless devices, the ISM band becomes more and more crowded. These heterogeneous devices have to compete with each other to access spectrum resources, generating cross-technology interference (CTI). Since CTI may destroy wireless communication,...
The problem of forming an FMICW signal for vertical-incidence single-antenna ionosonde based on the USRP platform using SDR technology was solved. We carried out studies aimed at getting a constant level of a received signal, unambiguous determining virtual reflection height in the required range as well as reducing interference and correlation noise during transmission and compression. The developed...
Modifying the logic at register transfer level can help to protect a circuit against counterfeiting or illegal copying. By adding extra gates, the outputs can be controllably corrupted. Then the circuit operates correctly only if the right value is applied to the extra gates. The main challenge is to select the best position for these gates, to alter the circuit's behaviour as much as possible. However,...
The probabilistic patch-based similarity measure (PPBSM) is a deeply studied and widely used method for synthetic aperture radar (SAR) image processing and understanding. Considering its performance limitation, we propose a preliminary exploration of integrating the spatial correlation information into the PPBSM, and design a refined method for SAR image change detection.
Due to the unreliable nature of wireless links, sensor nodes frequently encounter degraded performance or lack of connection. This paper provides a real-time status monitoring and channel error diagnosis method in a wireless sensor network. It uses a poll and echo procedure to efficiently collect some physical layer and link layer statistics from both transmitter side and receiver side. A machine...
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