DWT变换的另一种快速DHT算法

通过建立各类N阶离散W变换（DWT）到N阶离散Hartley（DHT）的转换,得到了另一种利用DHT统一计算各类DWT的更为简明的快速算法。该算法结构简单,无需事先判断数据长度N的奇偶性,同时可充分利用输入输出数据的对称与反对称性,使运算量进一步减少。     

任意长度离散Hartley变换的快速算法

本文把长为plq(p为奇数,q为任意自然数)的DHT转化为Pl个长为q的DHT的计算及其附加运算,附加运算只涉及P点cos-DFT和sin-DFT的计算;对长度(P1l,1,Psls 2l (p1, , ps为奇素数)的DHT,用同样的递归技术得到其快速算法,因而可计算任意长度的DHT;文中还论证了计算长为N的DHT所需的乘法和加法运算量不超过O(Nlog2N)。当长度为N=pl时,本文算法的乘法量比其他已知算法更少。     

各类离散W变换的快速Hartley变换算法

本文通过建立各类N阶离散W变换(DWTs)到N阶离散Hartley变换(DHT)的转换,得到了一种利用DHT 统一计算各类DWTs的非常简单的快速算法.该算法结构简单,且每一种转换过程总的运算量均低于5N.     

二维离散余弦变换的一种新的快速算法

本文介绍了二维离散余弦变换（ＤＣＴ）的一种新的快速算法，对于Ｎ×Ｎ ＤＣＴ（Ｎ＝２＾ｍ），只需用Ｎ个一维ＤＣＴ和若干加法运算。与常规的行－列法相比，所需的乘法运算量减少了一半，也比其它的快速算法的乘法运算量要少，而加法运算量基本上是相同的。     

二维离散余弦变换的一种新的快速算法

介绍了二维离散余弦变换的一种新的快速算法，对于Ｎ×ＮＤＣＴ（Ｎ＝２ｍ），只需用Ｎ个一维ＤＣＴ和若干加法运算，与常规的行一列法相比，所需的乘法运算量减少了一半，也比其它快速算法的乘法运算量要少，而加法运算量基本上是相同的。     

二维离散余弦变换的一种新的快速算法

本文介绍了二维离散余弦变换(DCT)的一种新的快速算法。对于NN DCT(N=2m),只需用N个一维DCT和若干加法运算。与常规的行-列法相比,所需的乘法运算量减少了一半,也比其它的快速算法的乘法运算量要少,而加法运算量基本上是相同的。     

一种计算MDCT的快速算法

提出了一种计算ＭＤＣＴ的快速算法，并分析了算法的计算复杂度。与利用ＦＦＴ计算的算法相比，本算法的计算复杂度降低了约一半。最后给出该算法的计算机仿真结果。     

一种快速,低运算量的信道辨识算法

在离散多音频（ＤＭＴ）系统中,保证通信正常进行的关键之一是完成收发信机的时域和频域均衡器的正确设置。一般的均衡器训练算法计算量较大。为了降低对计算量的要求,同时保证的精确度,本文提出一种基于信道辨识的均衡器训练算法。该算法将信道等效为一个ＡＲＭＡ（自回归滑动平均）模型,应用正交最小二乘法（ＯＬＳ）可快速估计出这个ＡＲＭＡ模型的阶数和参数,同时也就得到了均衡器系数的值。实验结果证明,本算法计算量较小     

快速傅立叶变换算法概述

快速傅立叶变换（FFT）属于数字信号处理中最基础的运算,已广泛应用于通讯、医学电子学、雷达或无线电天文学等领域。对FFT的主要算法进行了概述 ,并对其特性和运算工作量进行了分析和对比,期望对快速傅立叶变换算法有一个清晰的认识。     

A fast algorithm for discrete hartley transform of arbitrary length

DHT of length p~lq(p is odd and q is arbitrary) is turned into p~l DHTs of length qand some additional operations, while the additional operations only involves the computation ofcos-DFT and sin-DFT with length p. If the length of a DHT is p_1~(l_1)…P_N~(l_N)2~l(P_1…,P_N are oddprimes), a fast algorithm is obtained by the similar recursive technique. Therefore, the algorithmcan compute DHT of arbitrary length. The paper also Proves that operations for computingDHT of length N by the algorithm are no more than O(Nlog_2N), when the length is N=p~l,operations of the algorithm are fewer than that of other known algorithms.     

Robust Audio Fingerprinting Method Using Prominent Peak Pair Based on Modulated Complex Lapped Transform

The robustness of an audio fingerprinting system in an actual noisy environment is a major challenge for audio‐based content identification. This paper proposes a high‐performance audio fingerprint extraction method for use in portable consumer devices. In the proposed method, a salient audio peak‐pair fingerprint, based on a modulated complex lapped transform, improves the accuracy of the audio fingerprinting system in actual noisy environments with low computational complexity. Experimental results confirm that the proposed method is quite robust in different noise conditions and achieves promising preliminary accuracy results.     

任意长离散余弦变换的快速递归算法

该文基于Clenshaw递归公式以及离散余弦自身的对称性提出任意长离散余弦变换(DCT)的一种并行递归快速算法,给出了该算法的滤波器实现结构;与现有的其它递归算法以及基于算术傅里叶变换的余弦变换算法进行了计算复杂度的比较分析,结果表明该文算法运算量大大减少。该递归计算的滤波器结构使算法非常适合大规模集成电路(VLSI)实现。     

NEW FAST ALGORITHM OF 2-D DISCRETE COSINE TRANSFORM

In this paper, a new algorithm for the fast computation of a 2-D discrete cosine transform (DCT) is presented. It is shown that the N×N DCT, where N = 2m, can be computed using only N 1-D DCT's and additions, instead of using 2N 1-D DCT's as in the conventional row-column approach. Hence the total number of multiplications for the proposed algorithm is only half of that required for the row-column approach, and is also less than that of most of other fast algorithms, while the number of additions is almost comparable to that of others.     

任意平面分层介质中正演计算的快速方法

在非均匀介质电磁散射、逆散射等领域中，正演计算速度直接影响着反演计算效率。快速高精度的正演计算方法有利于反演效率的改善。对于任意平面分层介质情形，传统高效的数值模式匹配法的正演计算效率并不很高。本文通过首先推得每一从向分层中场量的汉克尔变换表达，再用快速傅里叶变换来完成汉克尔变换计算，从而得到更高效的计算方法。它避免了数值本征模式的求解，特别适用于处理平面分层介质中纵向分层较多的情形。对于其它非均     

任意2n阶列率递增顺序斜变换及其快速算法与应用

本文分析了斜变换基矢量按列率递增顺序排列的规律,给出了任意2n阶列率递增顺序斜变换的公式及其快 速算法,使斜变换理论完备化。将该算法应用于图像压缩,其变换域数据的熵接近常用的离散余弦变换,但运算速度较快。 该算法适用于需要高速处理和硬件实现的正交变换场合。     

Modulated Lapped Transform Domain Acoustic Echo Canceller with Double Talk Detector

A complete acoustic echo cancellation system with double talk detection capability is presented in this paper. The proposed system includes a new acoustic echo canceller (AEC) based on the modulated lapped transform (MLT) domain adaptive structure and a robust two-stage double talk detector (DTD) to cope with MLT domain AEC. The proposed AEC achieves better signal decorrelation via orthogonal MLT of size 2N× N rather than N× N square orthogonal transform such as DCT, DFT, etc. Both the input signal and the desired response are modulated lapped transformed in order to reduce the adaptation error between them so that the signal adaptation is purely operated in MLT domain. As a complementary of this, a two-stage DTD is developed to stabilize the operation of the AEC. The proposed DTD has robust algorithm structure and it allows faster switching according to the talker state change.Several simulation results with a synthetic and real speech are presented to demonstrate the performance of the proposed AEC and DTD. The proposed MLT based AEC proven to be very useful for the echo cancellation applications requiring high convergence speed and good echo attenuation. It can achieves faster convergence rate by more than twice over those of traditional DCT based AEC with an additional advantage of 10–15 dB ERLE improvement. On the other hand, a proposed two-stage DTD is shown to react quickly to both the onset and the end of the double-talk with reasonable high accuracy.