Multidimensional Signal Processing Using Mixed-microwave-digital Circuits and Systems PDF Download

Author: Arindam Sengupta
Publisher:
ISBN:
Category : Beamforming
Languages : en
Pages : 128

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Book Description
Wideband beamforming is an essential requirement for several areas of importance, such as radar, cognitive radio and wireless communications. Emerging ultra-wideband (UWB) systems demand rapid electronic steerability, and multiple beams, while maintaining a relatively constant far-field beamwidth. Traditional phased-array based coherent summing approaches generally fail to comply with the requirements of the UWB systems, and implementing such architectures on a hardware level is computationally intensive. Moreover, digital signal processing (DSP) of wideband signals require sophisticated front-ends for pre-processing stages, followed by analog-to-digital converters (ADCs) operating at a very high frequency of operation. In this study, a novel approach to mitigate the ADC requirements is explored, by using both microwave channelizers and sub-sampling ADCs. The microwave channelizer splits the incoming wideband signals into narrower bands, which are then digitized using subsampling ADCs. The resulting signals are simultaneously down-sampled and down-converted. This approach is investigated for a planar manifold-type microwave channelizer, integrated with multi-dimensional filters, to aid 2-D and 3-D wideband directional beamforming systems. The proposed 3-D architecture was investigated for focal plane array (FPA) applications, in order to exploit the high gain of a parabolic dish reflector, while achieving support for multiple electronically scanned beams, by replacing existing horn antennas with an FPA placed at the focal point of the dish. Such architectures, with the aid of the recently proposed frustum shaped filters, find many applications in radar, radio astronomy and other microwave imaging techniques. A novel 2-D bio-inspired spatially band-pass multi-beam filter, from the 1-D electrical equivalent of a mammalian cochlea, is explored. The proposed architectures were evaluated for performance under various scenarios involving wideband directional interference, off-dish interference and additive white Gaussian noise (AWGN), and were found to demonstrate significant noise rejection and subsequent desired signal enhancement. VLSI architectures for three high-precision fast division algorithms are presented. Such architectures are of extreme importance for several fields, that require real-time high-precision fast computations, such as, digital signal processing, information theory, cryptography, graph theory, and next generation of computational devices.