Area coverage adaptive nulling from geosynchronous satellites: Phased arrays versus multiple-beam antennas

Abstract

Antenna design trade-offs associated with providing an area coverage communication link via a geosynchronous satellite, where the geographical area to be serviced by the associated adaptive antenna system is characterized by a narrow-cone angle directed at an a priori known region on the earth's surface, are considered. Interference sources within and just surrounding the coverage area are adaptively nulled: interference sources located far from the coverage area are minimized by designing the antenna system to have low sidelobes outside the coverage area. This minimizes the number of adaptive channels which must he processed, with subsequent decrease in satellite weight and power requirements. The antenna design trade-off is between the phased array (PA) and the multiple-beam antenna (MBA). Three specific performance factors are considered in the MBA/PA design trade-off: susceptibility to out-of-coverage-area interference sources which use up the adaptive degrees of freedom allocated to the desired coverage area: effects of reduced link margin for low-gain thinned arrays: and nulling bandwidth restrictions imposed on spread spectrum communication systems.

Trends in Adaptive Array Processing

“…One way of accelerating the convergence is to decouple the inputs to the adaptive feedback system, which corresponds to diagonalizing the covariance matrix. An alternate way of decoupling the output ports is to incorporate the output ports with multiple beam antenna (MBA) system [65]. This leads to partially 8 International Journal of Antennas and Propagation diagonalized covariance matrix that is a diagonally dominant matrix and has an improved dynamic performance [66].…”

Robust Adaptive Beamforming for Multiple Signals of Interest with Cycle Frequency Error

“…For many practical applications, such as satellite communications [9], an antenna array is required to possess the beamforming capability that receives more than one SOI with specified gain constraints while suppressing all SNOI. This goal can be achieved using an antenna array with a multiple-beam pattern [9,10]. Recently, a novel cyclostationarity-exploiting beamforming method has been proposed by [11] for dealing with the situation of multiple SOIs based on the LS-SCORE algorithm.…”

Adaptive Array Beamforming Using Signal Cyclostationarity and Finite Data

“…For many practical applications, such as satellite communications [6], an antenna array is required to possess the beamforming capability that receives more than one SOI with specified gain constraints while suppressing all SNOIs. This goal can be achieved by using an antenna array with a multiple-beam pattern [6,7]. Recently, a novel cyclostationary beamforming method based on the LS-SCORE algorithm has been proposed by [8] for dealing with the situation of multiple SOIs.…”