This letter proposes an antenna array synthesis technique based on simultaneous perturbation stochastic approximation (SPSA) for sparse linear arrays with multiple constraints. The constraints include the number of elements, the array aperture, and the minimum and the maximum distance between two adjacent elements. With a novel vector mapping between the element spacings and the variables of SPSA, the constrained optimization problem is simply transformed to a nonconstrained optimization problem, and the infeasible solutions are naturally avoided. Simulation results confirm the great efficiency and the robustness of the proposed method and show that our method can achieve better results with fewer numbers of elements than other existing methods. Moreover, based on this algorithm, the optimal thinning levels of sparse arrays are studied. The results may be used as a reference to the linear array design.

Synthesis of Sparse Linear Arrays Using Vector Mapping and Simultaneous Perturbation Stochastic Approximation

Challenging simulation practice (failure and success) on implicit tracking control of double-integrator system via Zhang-gradient method

Overview on the development and applications of antenna control systems

Received Jan 12, 2015 Revised Feb 9, 2015 Accepted Feb 20, 2015 In the mobile communication via satellite, received systems are mounted on the mobile device such as ship, train, car or airplane. In order to receive continuous signals, received antenna system must be steered in both the azimuthal and elevation angle to track a satellite. This paper proposes the improved step-tracking algorithm using for mobile receiver system viasatellite Vinasat I. This paper also presents the results of study, design and manufacture of the discrete-time controller system for the fast tracking of a satellite by applying an improved step tracking algorithm with fuzzy proportional integral derivativecontroller. Simulated and experimental results indicate that the system performances obtain from applying the improved step tracking algorithm and the fuzzy controller was better than traditional control systems. Keyword:

Improvement of Steptracking Algorithm Used Formobile Receiver System Via Satellite

The binary offset carrier (BOC) proposed for the global navigation satellite systems (GNSS) will enhance navigation performance and spectrum compatibility. However, the acquisition process is made more complex, due to the ambiguity in the autocorrelation function (ACF) of BOC. This paper proposes an unambiguous acquisition technique for the new cosine phased BOC (cosine-BOC) modulated signals, which will most likely be used in both European Galileo system and Chinese Compass system. The test criterion employed in this technique is based on a synthesized correlation function which completely removes major positive side peaks while keeping the sharp main peak using the concept of simultaneous perturbation stochastic approximation (SPSA). Theoretical analysis and simulation results indicate that the proposed technique completely removes the ambiguity threat in acquisition process with some performance degradation. This technique is also suitable for arbitrary order cosine-BOC signals.

Minli Yao

Papers

SPSA-based step tracking algorithm for mobile DBS reception