access icon openaccess Generation scheme of chirp scaling phase functions based on floating-point CORDIC processor

This is an open access article published by the IET under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/)
Received 25/02/2019, Accepted 08/05/2019, Published 11/07/2019

This study presents a chirp scaling (CS) phase function generation scheme based on CORDIC algorithm, it adopts single precision floating-point CORDIC processor to implement a variety of non-linear operations which are involved in CS synthetic aperture radar (SAR) imaging algorithm. We extend the range of convergence of CORDIC algorithm and reduce the data width in rotation unit module by adopting a hardware resource reduction scheme. We also adopt a unified CORDIC processor to achieve square root, multiplication, and division operation, which can substitute multiple single-function processors and simplify the complicate arithmetic in CS algorithm. As a proof of concept, we verify the performance of the proposed design scheme on Xilinx XC7VX690T FPGA platform, it is also applied to 16384 × 16384 points target SAR imaging system, the FPGA resource occupancy of the CS phase function generation module demonstrates that the usage of CORDIC processor can effectively save the consumption of hardware resources, and the maximum operating frequency is acceptable. The accuracy of phase functions can satisfy the engineering requirements.

Inspec keywords: logic design; floating point arithmetic; field programmable gate arrays; synthetic aperture radar; function generators; radar imaging

Other keywords: square root operation; nonlinear operations; hardware resource reduction scheme; CORDIC algorithm; multiplication operation; chirp scaling phase functions; chirp scaling phase function generation scheme; division operation; Xilinx XC7VX690T FPGA platform; unified CORDIC processor; CS synthetic aperture radar imaging algorithm; SAR imaging system; single precision floating-point CORDIC processor

Subjects: Digital circuit design, modelling and testing; Radar equipment, systems and applications; Logic design methods; Logic circuits; Function generators; Computer vision and image processing techniques; Optical, image and video signal processing; Logic and switching circuits; Digital arithmetic methods

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