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In this paper, matched-field localization with a single vector hydrophone is researched. In condition of ideal waveguide, the sound pressure field and vertical velocity were analyzed theoretically. The relationship between acoustic pressure field and vector field achieved that a vector hydrophone can be equivalent to vertical two element array with a certain vertical aperture. The depth of vector...
In the part of geophysics researches, the method Double Beam Forming (DBF) was found for separating the surface waves from the seismic waves. According to one of the kernels of DBF : extraction of group velocity and phase velocity, this paper benefit from this idea and concentrate on the time delay estimation (TDE) which is one of the key techniques in the array signal processing. The sound velocity...
In this paper, a minimax anti-jamming strategy in a frequency hopping spread spectrum (FHSS)/quadrature phase-shift keying (QPSK) satellite communication system is developed. The goal of the anti-jammer is to minimize symbol error probability while that of the jammer is to maximize it. The jammer attacks legitimate communication system via two jamming strategies: single-tone jamming and full-band...
Spectral efficiency and energy efficiency are fundamental trade-off in wireless communications. Spectral efficiency (SE), defined as the average data rate per unit bandwidth, quantifies how efficiently the available spectrum is utilized. Energy efficiency (EE), defined as the successful transmitted information bits per unit energy from transmitter to receiver, quantifies how efficiently the energy...
Engineering systems rely on robust, continuous, and resilient communications. To ensure robustness, communication systems should operate in situations of intentional interference. Specifically, cognitive radio frequency interferences (RFI) for a frequency hopping system will be demonstrated to maximize probability of interception, while probability of RFI detection is maintained. Three test conditions...
This paper presents an accurate approximation of the frame error rate (FER) of coded wireless communication systems with receiver diversity, such as single-input multiple-output (SIMO) systems with maximum ratio combining (MRC) or hybrid automatic repeat request (HARQ) systems with Chase combining. The signals at different diversity branches experience independent but non-identically distributed Rayleigh...
The optimum energy efficient communication of a hybrid automatic repeat request (HARQ) system with Chase combining is studied in this paper. The proposed scheme minimizes the energy required to successfully deliver a bit from a source to its destination by identifying the optimum energy distribution, i.e., the sequence of transmission energy that should be employed during the retransmissions of a...
Energy efficiency (EE) and spectral efficiency (SE) feature one of the most fundamental tradeoffs in communication systems. In this paper, we propose an optimum transmission scheme for coded Type-I automatic repeat request (ARQ) systems to balance the EE-SE tradeoff. The optimization is performed with respect to a new design metric, the normalized EE (NEE), which is defined as the energy per bit normalized...
ARQ for network coding (ANC) can effectively improve the throughput and reliability of transmission. The properties of ANC are analyzed from three different delay definitions which are seeing delay, decoding delay and delivery delay, respectively. Without perfect feedback information, a novel network coding scheme with lossy and delayed feedback (NCLDF) is developed in this paper. Simulation results...
We derive detection metrics for soft-output diversity combining for the case of imperfect channel state information at the receiver. We treat in particular the case when the noise variance at the receiver is unknown. We contrast conventional training-based methods to a detector based on the generalized likelihood-ratio (GLR) test paradigm. We study the performance of the detectors via EXIT chart analysis...
A practical variational Bayes (VB) iterative receiver with joint signal detection and channel estimation is proposed in this paper for MIMO-OFDM systems in time-varying multipath channel. Since the VB method provides distribution-estimates of the parameters, the soft-input soft-output (SISO) QRD-M algorithm is exploited to estimate the signal distribution, and several channel estimation algorithms...
In this paper, a CUWB system model with coexistence of multinode is studied. Based on the assumption that interfering nodes are Gaussian distribution in cognitive nodepsilas region, outage probability is used to evaluate the performance of system. Theoretical analysis and numerical simulations indicate that density of interfering nodes, radius of the distributed area and interference threshold all...
In this paper, the effects of the antenna shapes on the indoor MIMO channel capacity are analyzed based on a rigorous numerical model. Based on network theory, we first give the rigorous MIMO channel transfer function using the admittance matrices of the transmitter and receiver, and the admittance matrix between them. Consequently, we use the multilevel Green's function interpolation method (MLGFIM)...
In this paper, we derived two new decision metrics for the non-coherent maximum a posteriori (N-MAP) detector and the generalized-likelihood ratio (GLR) detector. The proposed detectors are optimally designed to make use of the available estimated channel. The obtained results show that the proposed detectors can outperform a system using classical training-based maximum-likelihood (TBML) detector...
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