Low-Power, Low-Complexity Bit-Serial VLSI Architecture for 1D Discrete Wavelet Transform

Abstract

The discrete wavelet transform (DWT) is an upcoming compression technique that has been selected for MPEG-4 and JEPG 2000, because it has no blocking effects and it efficiently determines the frequency property of the temporary signals. In this paper, we propose a low-complexity, low-power bit-serial DWT architecture, employing a two-channel lattice-based quadrature mirror filter (QMF). The filter consists of four lattices (filter length = 8), and we determine the quantization bit for the coefficients using a fixed-length peak signal-to-noise ratio analysis and propose the architecture of the bit-serial multiplier with a fixed coefficient. The canonical signed digit encoding for the coefficients is applied to minimize the number of nonzero bits, thus reducing the hardware complexity. The proposed folded one-dimensional DWT architecture processes the other resolution levels during idle periods by decimations, and it provides efficient scheduling. The proposed architecture requires only flip-flops and full adders. This architecture has been designed and verified by the Verilog HDL and synthesized using the Synopsys Design Compiler with the DongbuAnam 0.18 μm Standard Cell Library. The maximum throughput is 393 Mbps at 450 MHz with a latency of 16 clocks, and the gate count is about 5K in equivalent two-input NAND gates. The dynamic power is 7.02 mW at 1.8 V. The data scheduling using a data dependency graph, and the performance, power, and required hardware cost are discussed.