Efficient coding of speech and audio in a distributed system requires that quantization errors across nodes are uncorrelated. Yet, with conventional methods at low bitrates, quantization levels become increasingly spa...
详细信息
Efficient coding of speech and audio in a distributed system requires that quantization errors across nodes are uncorrelated. Yet, with conventional methods at low bitrates, quantization levels become increasingly sparse, which does not correspond to the distribution of the input signal and, importantly, also reduces coding efficiency in a distributed system. We have recently proposed a distributed speech and audio codec design, which applies quantization in a randomized domain such that quantization errors are randomly rotated in the output domain. Similar to dithering, this ensures that quantization errors across nodes are uncorrelated and coding efficiency is retained. In this paper, we improve this approach by proposing faster randomization methods, with a computational complexity of O(N log N). The presented experiments demonstrate that the proposed randomizations yield uncorrelated signals, that perceptual quality is competitive, and that the complexity of the proposed methods is feasible for practical applications.
A fast algorithm is proposed for solving symmetric Toeplitz systems. This algorithm continuously transforms the identity matrix into the inverse of a given Toeplitz matrix T. The memory requirements for the algorithm ...
详细信息
A fast algorithm is proposed for solving symmetric Toeplitz systems. This algorithm continuously transforms the identity matrix into the inverse of a given Toeplitz matrix T. The memory requirements for the algorithm are O(n), and its complexity is O(log kappa(T)nlogn), where kappa(T) is the condition number of T. Numerical results are presented that confirm the efficiency of the proposed algorithm.
作者：
Chen, ZCUNY
New York City Coll Technol Dept Math Brooklyn NY 11201 USA
In applied mathematics, computer science and engineering, new techniques are developed to improve efficiency of computations. Recently, the displacement structure has been investigated thoroughly and implemented in th...
详细信息
ISBN:
(纸本)1892512459
In applied mathematics, computer science and engineering, new techniques are developed to improve efficiency of computations. Recently, the displacement structure has been investigated thoroughly and implemented in the efficient computations of many structured matrices. In this paper, a novel class of strutured matrix over a field with displacement structure, refereed as a C-Cauchy-like matrix, will be formulated and presented. Using the displacement approach, a new super-fast algorithm for the multiplication of a C-Cauchy-like matrix of the size n x n over afield with a vector will be designed The memory space cost of the number of the elements stored for a C-Cauchy-like matrix of the size n x n over afield is O(n) versus n(2) for a general matrix of the size n x n over afield. The cost of the number of the arithmetic operations the product of a C-Cauchy-like matrix and a vector is reduced dramatically to O(n) from O(n(2)).
暂无评论