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MIMO-OFDM is commonly used for communication system because it provides high data rates and fading effect which is introduced by multipath propagation; the system is robust against it. In MIMO-OFDM, channel estimation is a crucial technique for the estimation of the transmitted signal bits upon the received signal bits. Designing pilot pattern is an important step to realize PSA-OFDM. For channel...
In the context of global navigation satellite systems, this paper addresses the problem of refining the Doppler frequency estimation provided in the acquisition stage for highorder binary offset carrier (BOC) signals in post-correlation. The refinement of Doppler frequency must be done because the estimation obtained from the acquisition stage is not usually accurate enough to track the signal in...
In recent years, the problem of Position, Navigation and Timing (PNT) resiliency has received significant attention due to an increasing awareness on threats and the vulnerability of the current GNSS signals. Several proposed solutions make uses of cryptography to protect against spoofing. A limitation of cryptographic techniques is that they introduce a communication and processing computation overhead...
The detection and localisation of multiple GNSS jammers in densely populated areas seems to be already a need due to the availability and proliferation of very cheap and small GNSS jammers (together with the raise of the privacy awareness), and the increasing number of services and applications relying on the GNSS signals for its operation. Densely populated areas do not only introduce the possibility...
A dynamic wireless power transfer (WPT) system for electric vehicles has to simplify its road-side facilities, which are installed over long distances. Although previous research has proposed secondary-side efficiency control, design constraints of the WPT system have to be imposed to obtain the reference value of the control. In this paper, an efficiency maximization method based on simultaneous...
We derive for the first time closed-form expressions for the Cramér-Rao lower bounds (CRLBs) of the joint channel phase, and carrier frequency offset (CFO) estimates from turbo-coded (TC) Pulse-amplitude modulation (PAM) and rectangular-QAM (RQAM) modulated signals over flat-fading channels. After wisely exploiting the properties of Gray mapping, we are able to simplify the log-likelihood...
Seismic data acquisition in remote locations involves sampling using regular grids of receivers in a field. Extracting the maximum possible information from fewer measurements is cost-effective and often necessary due to malfunctions or terrain limitations. Compressive Sensing (CS) is an emerging framework that allows reconstruction of sparse signals from fewer measurements than conventional sampling...
This paper considers the problem of moving target localization in noncoherent distributed multiple-input multiple-output (MIMO) radar systems by using the bistatic range and range rate measurements. We propose a weighted least squares (WLS) method to estimate the target position and velocity, and then use the semidefinite programming (SDP) method to improve the accuracy of the WLS estimation by relaxing...
This paper deals with the baseband digital demodulation of bursty BPSK signals in the presence of frequency, phase and time offset in an Additive White Gaussian Noise (AWGN) impaired narrowband satellite TDMA channel. The receiver perform the tasks of acquiring synchronization in time, frequency and phase, matched filtering, BPSK demodulation and soft decision Viterbi decoding on the received baseband...
A novel efficient blind estimation method is proposed for long-code direct sequences spread spectrum signals. The core idea of the proposed method is to construct an information symbol transition pattern matrix to eliminate the information symbol time varying damage to the periodic structure of pseudo-noise sequences for long-code DSSS signals. Then eigenanalysis approach is employed to estimate the...
The recovery of polarization and direction of arrivals (DOAs) of multiple targets locating at the same range but different angles in the forward-looking direction is of great trouble for conventional active radar. Based on compressive sensing (CS) framework, a joint polarization-DOA estimation strategy for single-input-multiple-output (SIMO) radar is proposed, which can reconstruct the sparse target...
This paper considers the problem of target localization from the bistatic range-sum measurements in noncoherent distributed multiple-input multiple-output (MIMO) radar system. The localization procedure includes two parts. First, it divides the measurements into several groups based on the different transmitter or receiver, and for each group, we use least squares (LS) approach based on squared range-sum...
The present work deals with optimized strategies to address the issue of link adaptation (Adaptive Coding and Modulation — ACM) in a multi-user multi-beam satellite system employing precoding at the gateway side. Accordingly, the focus is on the forward link of a multi-beam satellite system employing a full frequency reuse configuration. In such an interference limited setting, the Super-Framing structure...
Network diversity multiple access (NDMA) is the family of algorithms with the highest potential throughput in the literature of signal-processing assisted random access protocols. NDMA uses the concept of protocol-induced retransmissions to create an adaptive source of diversity. This diversity is used to resolve packet collisions employing signal separation tools without the explicit need (or as...
The spin of a projectile results in an amplitude and phase modulation on the received Global Positioning System (GPS) signal when superimposing the antenna signals from a uniform circular array (UCA) with the same amplitude and phase. Since the phase modulation can be considered more significant compared to the amplitude modulation, the influence of the phase modulation on the estimation of the position...
Received Signal Strength (RSS) localization has the attraction of requiring only simple receiver hardware. The basic idea is to find the position estimate that is most consistent with the received signal power measurements observed at multiple known locations in the area of interest. A fundamental assumption is that the signal power measurement is proportional to the product of the reference emitter...
An essential function for automated vehicle technologies is accurate localization. It is difficult, however, to achieve lane-level accuracy with low-cost Global Navigation Satellite System (GNSS) receivers due to the biased noisy pseudo-range measurements. Approaches such as Differential GNSS can improve the accuracy, but usually require an enormous amount of investment in base stations. The emerging...
Pseudolite-based systems and airborne relay-based positioning system (ARPS) have a limitation wherein the position error increases as the distance between the user and the area where the segments of the system are configured increases, owing to the low altitude of the navigation signal transmitters. To enhance the accuracy of the user, we propose a self-correction scheme based on the ARPS. In the...
This paper presents a WiFi-based device-free crowd counting and occupancy estimation system that can be used in rooms/environments different from the ones in which the training process has been performed. Therefore, crowd counting is achieved without requiring another training phase in each new environment. The proposed approach analyzes the shape of the Doppler spectrum of the received signal which...
The paper introduces a novel method for distance estimation based on an OFDM signal combined with the Zadoff-Chu sequences. By exploiting the properties of these sequences, it is possible to evaluate the distance between two active nodes with a very good precision and accuracy. The technique effectiveness is demonstrated by measuring the distance between a single transmitter and a synchronized receiver...
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