Array Signal Processing Algorithms Based On Broadband Conformal Antenna

Conformal array antenna has been widely used in the military and civilapplications. As signal processing module of a receiver, algorithm for the conformalarray signal processing algorithms are not fully studied now, especially for widebandDOA(Direction of Arrival) estimation and DBF(Digital Beamforming) algorithms thatbased on broadband conformal array. In addition, the CS(Compressive Sensing) theoryproposed in recent years could reconstruct original signal with fewer sampling. At thesame time, it is free of the array structure restrictions. These two features makes CStheory been extensively studied in the array signal processing field. However, mostresearch focuses on the omni-directional antenna element. So it is of great significanceto apply CS theory into conformal array signal processing.To address the above issues, based on broadband conformal array, DOA estimationand DBF algorithms which are free of preliminary estimates by using PM(PropagatorMethod) are studied carefully in this paper. DOA estimation and DBF implementationsbased on compressive sensing theory are also discussed. DOA estimation for broadbandconformal array are obtained with the help of the existing narrowband method. Themain contents are organized as follows.First, signal receiving data model of the narrowband array and wideband focusingalgorithms are introduced, and the theoretical of DOA estimation and DBF are alsodiscussed. A brief description of the principle of CS is given.Then, wideband DOA estimation without any initial DOA estimates or eigenvaluedecomposition operation based on PM is realized on a conformal array. By combiningPM with ESB(Eigenspace Beamformer), a new robust adaptive beamforming method isproposed. This approach is extended to the wideband signal processing to achieve arobust broadband digital beamformer method.Finally, DOA estimation based on compressive sampling array is studied in detail.DOA estimation by using sparse representation and off-grid technique is the focus ofthis paper. Off-grid technique is also extended to the wideband array signal processingand its DOA estimates performance is investigated on conformal array. Because CS could reconstruct the original array data from less elements, adaptive digitalbeamforming based on compressive sensing theory is discussed.