Dynamic Reconfigurable on the Lifting Steps Wavelet Packet Processor with Frame-Based Psychoacoustic Optimized Time- Frequency Tiling for Real-Time Audio Applications
Alexey Petrovsky, Maxim Rodionov, Alexander Alexandrovich Petrovsky · InTech eBooks · 2013
The discrete wavelet packet transform (DWPT) as a generalization of the standard wavelet transform provides a more flexible choices for time–frequency (time-scale) representation of signals [1] in many applications, such as the design of cost-effective real-time multimedia systems and high quality audio transmission and storage. In parallel to the definition of the ISO/MPEG standards, several audio coding algorithms have been proposed that use the DWPT, in particular, adaptive wavelet packet transform, as the tool to decompose the signal [2],[3]. In practice, DWPT are often implemented using a tree-structured filter bank [2], [3],[4]. The DWPT is a set of transformations that admits any type of tree-structured filter bank, that provides a different time–frequency tiling map. Many architectures have been proposed for computing the discreate wavlet transform in the past. However, it is not the case for the DWPT. There are very few papers regarding the development of specific architectures for the DWPT. In [5] is designed a programmable DWPT processor using two-buffer memory system and a single multiplier–accumulator (MAC) to calculate different subbands. Method [6] exploits the in-place nature of the DWPT algorithm and uses a single processing element consisting of multipliers in parallel and adders for each low-pass and high-pass filters – wavelet butterflies (is the number of filter taps) to increase the throughput. In [7] is also proposed a folded pipelined architecture to speed up the throughput. It consists of MACs communicated by memory banks to compute each level of the total decomposition levels.