Employing singular covariance matrix, spectral estimation methods can give high resolution results. In this paper, the original one-dimensional (1-D) spectral estimation method, which is based on singular covariance m...
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The efficiently calculate of the attitude matrix is an important subject in the Strap-down Inertial Navigation System (SINS), because the precision of its solution directly effects on the system performance. A new met...
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ISBN:
(纸本)0819460079
The efficiently calculate of the attitude matrix is an important subject in the Strap-down Inertial Navigation System (SINS), because the precision of its solution directly effects on the system performance. A new method of 3 rd order minimal parameter solution for the orthogonal matrix differential equation is used to solve the quaternion differential equation of SINS in this paper, and the numerical simulation is done as well. From the simulation result, we can see that when the new algorithm is used, the precision of the solved attitude angles is two orders higher than the classical method, and the floating-point operations is only abort half of the old one.
OFDM multihop system is efficient scheme to save energy and extend coverage. In this paper, optimal resource allocation in OFDM multihop system, including arbitrary number of hops and subcarriers, is studied. By joint...
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ISBN:
(纸本)9781424443376
OFDM multihop system is efficient scheme to save energy and extend coverage. In this paper, optimal resource allocation in OFDM multihop system, including arbitrary number of hops and subcarriers, is studied. By joint subcarrier matching and power allocation, our goal is to maximize system capacity with the system-wide power constraint. First, we formulate the optimal subcarrier matching and power allocation problem as an optimization problem, which is a mixed binary integer programming problem and prohibitive to find the global optimum. Then, by utilizing the special structure of the system, we propose a low complexity resource allocation scheme, which is proved to be globally optimal. The simulations prove that the proposed scheme improves the system capacity.
Downward looking ground penetrating radar (GPR) has been considered a viable technology for landmine detection. For such a GPR with the antennas positioned very close to the ground surface, the reflections from the gr...
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Because ordinary users cannot quickly obtain the three-dimensional space position of aircraft in the airport terminal area through a two-dimensional display navigation map, the aircraft surveillance simulation system ...
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The combination of multihop relay system and orthogonal frequency division multiplexing (OFDM) modulation is a promising way to increase capacity and extend coverage area. For OFDM two-hop relay system with separate p...
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ISBN:
(纸本)9781424443376
The combination of multihop relay system and orthogonal frequency division multiplexing (OFDM) modulation is a promising way to increase capacity and extend coverage area. For OFDM two-hop relay system with separate power constraints, we consider joint subcarrier matching and power allocation problem to maximize the system capacity, where the relay strategy is decode-and-forward. We formulate the optimal joint subcarrier matching and power allocation problem as an optimization problem, which is mixed binary integer programing problem and prohibitive to find global optimum in terms of complexity. By separating the subcarrier matching and power allocation, we provide the optimal scheme, i.e., optimal joint subcarrier matching and power allocation. Though simplifying the system architecture, the simulation proves that the one-to-one subcarrier matching is almost optimal.
Cryptic disasters in airport runway will bring about serious accident like crash. In order to detect and recognize diseases timely, a time-frequency feature extraction method based on Wigner distribution is proposed i...
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In this paper, a robust method for synthetic aperture radar interferometry (InSAR) interferometric phase estimation is introduced. In the method, the optimal joint data vector is determined, the generalized correlatio...
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The signal multipath effect is one of the main reasons which lead to positioning error in the Global Positioning System （GPS）. Although the differential technology can improve the positioning accuracy, the different...
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ISBN:
(纸本)9781467321969
The signal multipath effect is one of the main reasons which lead to positioning error in the Global Positioning System （GPS）. Although the differential technology can improve the positioning accuracy, the differential GPS system still can’t eliminate the positioning error caused by multipath signals, the reference stations and users being in different geographical environment. In the light of the GPS multipath signal model, this paper presents a GPS time delay estimation algorithm based on signal separation estimation theory. Firstly, Doppler frequency is estimated when the signal delay is unknown. Then, we use the estimated Doppler frequency to get signal delay information with signal separation estimation theory. In addition, we consider the previous estimated results as the initial value and a two-dimension optimization method is implemented in a small range for further improving the estimation accuracy. It can be shown from the simulation results that this method which is able to effectively eliminate the multipath has a better performance compared with the conventional method and narrow correlator spacing algorithm.
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