Title: A Single-Channel Architecture for Algebraic Integer Based 8$\times$8 2-D DCT Computation,
Abstract: An area efficient row-parallel architecture is proposed for the real-time
implementation of bivariate algebraic integer (AI) encoded 2-D discrete cosine
transform (DCT) for image and video processing. The proposed architecture
computes 8$\times$8 2-D DCT transform based on the Arai DCT algorithm. An
improved fast algorithm for AI based 1-D DCT computation is proposed along with
a single channel 2-D DCT architecture. The design improves on the 4-channel AI
DCT architecture that was published recently by reducing the number of integer
channels to one and the number of 8-point 1-D DCT cores from 5 down to 2. The
architecture offers exact computation of 8$\times$8 blocks of the 2-D DCT
coefficients up to the FRS, which converts the coefficients from the AI
representation to fixed-point format using the method of expansion factors.
Prototype circuits corresponding to FRS blocks based on two expansion factors
are realized, tested, and verified on FPGA-chip, using a Xilinx Virtex-6
XC6VLX240T device. Post place-and-route results show a 20% reduction in terms
of area compared to the 2-D DCT architecture requiring five 1-D AI cores. The
area-time and area-time${}^2$ complexity metrics are also reduced by 23% and
22% respectively for designs with 8-bit input word length. The digital
realizations are simulated up to place and route for ASICs using 45 nm CMOS
standard cells. The maximum estimated clock rate is 951 MHz for the CMOS
realizations indicating 7.608$\cdot$10$^9$ pixels/seconds and a 8$\times$8
block rate of 118.875 MHz.