Hardware Acceleration of Beamforming in a UWB Imaging Unit for Breast Cancer Detection

[摘要] The Ultrawideband (UWB) imaging technique forbreast cancer detection is based on the fact that cancerouscells have different dielectric characteristics than healthy tissues. When a UWB pulse in the microwave range strikes a cancerousregion, the reflected signal is more intense than the backscatteroriginating from the surrounding fat tissue. A UWB imagingsystem consists of transmitters, receivers, and antennas for the RFpart, and of a digital back-end for processing the received signals. In this paper we focus on the imaging unit, which elaboratesthe acquired data and produces 2D or 3D maps of reflectedenergies. We show that one of the processing tasks,Beamforming,is the most timing critical and cannot be executed in softwareby a standard microprocessor in a reasonable time. We thuspropose a specialized hardware accelerator for it. We design theaccelerator in VHDL and test it in an FPGA-based prototype. We also evaluate its performance when implemented on a CMOS45 nm ASIC technology. The speed-up with respect to a softwareimplementation is on the order of tens to hundreds, dependingon the degree of parallelism permitted by the target technology.

[学科分类] 电子、光学、磁材料