Design and Implementation of Approximate DCT Architecture in Quantum-Dot Cellular Automata
Ali Newaz Bahar, Khan A. Wahid
Abstract
Quantum-dot cellular automata (QCA) is recognized as one of the rapidly growing nanotechnologies and an alternate to CMOS at the nanoscale. The QCA technology is capable of designing nanoscale digital circuits with a clock speed of terahertz range and ultralow power consumption. In this article, an effective single-layer binary discrete cosine transform (BinDCT) has been reported. To realize the BinDCT architecture in QCA, we also proposed several associated combinational and sequential logic elements of low complexity. All reported circuit layouts were designed and verified using the QCADesigner tool. Moreover, QCAPro is used to estimate the energy dissipation. All comparative study indicates that the reported designs are superior to previous designs in terms of cell complexity, covered area, and energy dissipation. In particular, the proposed QCA BinDCT achieved 39% cell count and 20% covered area improvements compared with the previous QCA BinDCT architecture. Moreover, in terms of power dissipation, the proposed QCA BinDCT dissipates 1.394 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> mW, whereas CMOSand QCA-based BinDCT architectures consume 0.195 and 0.091 mW of power, respectively.