Low-Complexity Algorithm of Recursive Analysis and Synthesis Quadrature Mirror Filterbanks for Digital Radio Mondiale

This paper proposed a low-complexity algorithm and of analysis and synthesis quadrature mirror filter banks (AQMF, SQMF) on the spectral band replication (SBR) for digital radio mondiale (DRM). Based on recent Lai et al.'s concept, an extended issue is addressed form the view point of recursively computing the AQMF and SQMF coefficients. The proposed recursively computational method not only combines with the lifting scheme algorithm but also employs the fixed-coefficient concept to introduce the technique of canonical signed digit (CSD) multiplication. The results show that the proposed QMFs algorithm has a great improvement on multiplication of computational complexity. For the recursive kernel computation (N=64), the proposed method can transfers the constant multiplication into addition by using CSD technique which brings a great improvement in the complexity of multiplication and the requirement of coefficient. The overall complexity of the proposed algorithm (N=64) has 93.46% reduction of multiplication and 73.73% reduction of coefficient. It would be more efficient and more suitable than previous works for DRM applications.

I. Introduction

High-efficiency advanced audio coding (HE-AAC) [1] employs new spectral band replication (SBR) tools to improve audio quality, but this considerably increases the computational complexity. To meet full-duplex communication applications for high-efficiency and low algorithmic-delay audio coding, the MPEG committee released a new standard “Advanced Audio Coding-Enhanced Low Delay” (AAC-ELD) [2]. For digital audio broadcasting, Digital Radio Mondiale (DRM) [3] offers many audio-coding technologies, such as AAC, CELP, and HVXC codecs. Moreover, a new high-frequency reconstruction method (i.e., SBR) has been used to enhance the perceptual audio quality of these source coding schemes.