公开(公告)号：US20020099537A1

公开(公告)日：2002-07-25

申请号：US10043517

申请日：2002-01-11

Applicant: U.S. PHILIPS CORPORATION

Inventor： Ludovicus M.G.M. Tolhuizen ,  Robert J. Sluijter

IPC: G10L021/00 ,  G10L019/00

CPC classification number: G10L19/005 ,  G10L2019/0001 ,  G10L2019/0013

Abstract: In a transmission system a signal to be transmitted is applied to a source encoder (4) for being encoded. The encoded signal is applied to a channel encoder (6) which applies an error correcting code on the encoded input signal. The output signal of the channel encoder (6) is transmitted to a receiver (14) which processes the received signal by means of a channel decoder (18) and a source decoder (20). The source encoder comprises a codebook entry selector (42) which selects a ternary number generated by a ternary generator (26), such that a synthetic signal derived from said ternary number is a best approximation of a signal to be encoded. The ternary value found in this way is converted into a binary number in such a way that the ternary values corresponding to binary numbers which differ only in one particular digit, differ only in one single digit. This has the advantage that a transmission error of in said particular digit has a small perceptual effect, because the corresponding ternary number differ only slightly. In a preferred embodiment the numerical value of a first codebook entry corresponds to an index of a second codebook entry, and the numerical value of the second codebook entry corresponds to the index of the first codebook entry.

Abstract translation: 在传输系统中，要发送的信号被施加到用于编码的源编码器（4）。 编码信号被施加到在编码的输入信号上应用纠错码的信道编码器（6）。 信道编码器（6）的输出信号被发送到接收机（14），接收机（14）借助于信道解码器（18）和源解码器（20）处理接收的信号。 源编码器包括码本条目选择器（42），其选择由三元生成器（26）生成的三进制数，使得从所述三进制数导出的合成信号是待编码的信号的最佳近似值。 以这种方式找到的三元值被转换为二进制数，使得对应于仅在一个特定数字中不同的二进制数的三元值仅在一个数字中不同。 这样做的优点在于，所述特定数字的传输误差具有较小的感知效果，因为对应的三进制数不同。 在优选实施例中，第一码本条目的数值对应于第二码本条目的索引，并且第二码本条目的数值对应于第一码本条目的索引。

公开(公告)号：US20020123885A1

公开(公告)日：2002-09-05

申请号：US10084714

申请日：2002-02-25

Applicant: U.S. PHILIPS CORPORATION

Inventor： Robert J. Sluijter ,  Rakesh Taori

IPC: G10L021/00 ,  G10L019/00

CPC classification number: G10L19/04 ,  G10L19/22

Abstract: In a speech transmission system, an input speech signal is applied to a speech encoder (12, 36) for encoding the input speech signal. The encoded speech signal is transmitted via a communication channel (10) to a speech decoder (30, 48). In order to improve the performance of the transmission system in the presence of background noise, it is proposed to introduce background noise dependent processing elements in the speech encoder (12, 36) and/or in the speech decoder (30, 48) In a first embodiment of the invention, the parameters of the perceptual weighting filter (124) in the speech encoder (12, 36) are derived by calculating linear prediction coefficients (null) from a speech signal which is processed by means of a high-pass filter (82). In a second embodiment of the invention, an adaptive post filter (150) in a speech decoder (30, 48) is by-passed when the noise level exceeds a threshold value.

Abstract translation: 在语音传输系统中，输入语音信号被应用于用于编码输入语音信号的语音编码器（12,36）。 经编码的语音信号通过通信信道（10）发送到语音解码器（30,48）。 为了在背景噪声的存在下提高传输系统的性能，提出了在语音编码器（12,36）和/或语音解码器（30,48）中引入背景噪声相关处理元件。在 本发明的第一实施例中，语音编码器（12,36）中的感知加权滤波器（124）的参数是通过从通过高通滤波器处理的语音信号的线性预测系数（â） （82）。 在本发明的第二实施例中，当噪声电平超过阈值时，语音解码器（30,48）中的自适应后置滤波器（150）被旁路。