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Adaptive antenna arrays, also known as smart antennae, are becoming progressively a viable alternative to larger antenna structures in a wide number of different scenarios. However, in order to take full advantage of the arrays' interference rejection and SNR (Signal-to-Noise Ratio) improvement capabilities, that is, in order to perform a correct signal beamforming via complex weights' manipulation,...
The use of spatial-domain signal processing for mitigation of interference signals in receivers of global navigation satellite systems (GNSS) allows for improvement of the overall system performance. To fully benefit from the use of adaptive antenna arrays, the individual signal processing paths in such a multi-antenna system should be thoroughly calibrated. The focus of this paper is on the specifics...
This paper presents a procedure used to calibrate a multi-beam antenna array to compensate for channel amplitude and phase mismatch. The multi-beam smart antenna is based on Butler matrix. The calibration algorithm of N elements array antenna involves transmission of N time multiplexed orthogonal encoded signals. The received signals are coherently detected, accumulated in vector forms, and a set...
Smart antenna technology can significantly improve the coverage radius, increase channel capacity, reduce transmitting power as well as overcome multipath effects by adaptive beamforming. The performance of digital beamforming is greatly affected by the amplitude-phase inconsistency among the channels. We propose a method of calibrating amplitude-phase errors of RF channels of DBF transmitting antenna...
The need for calibration in antenna arrays is a persistent challenge and is one of the impediments to their widespread integration into communication infrastructures. The choice of antenna array structure dictates the means by which calibration can be achieved. The antenna structure used here is a distributed source array with an interconnected measurement structure for calibration. This non-radiative...
In smart antenna downlink systems, the beamforming is severely affected by antenna gain and phase mismatch as well as mutual coupling effects. We propose an eigen-structure based approach to estimate the gain and phase of each antenna sensor and mutual coupling coefficients between antenna sensors. By preprocessing the transmission signal in base station with the estimated parameters, the gain and...
In this contribution, we have presented a preliminary analysis for the implementation of the calibration algorithm to a geodesic antenna array (GEODA) and propose a new algorithm for the on-line calibration. Some simulations was presented in order to allow us explain the scope of this project and the importance of compensate the errors presented at the uncalibrated antenna.
We consider space-time adaptive processing (STAP) when the radar returns are recorded by a conformal antenna array (CAA). The statistics of the secondary data snapshots used to estimate the optimum weight vector are not identically distributed with respect to range, thus preventing the customary STAP processor from achieving its optimum performance. The compensation of the range dependence of the...
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