公开(公告)号：US06240385B1

公开(公告)日：2001-05-29

申请号：US09161429

申请日：1998-09-24

申请人： Majid Foodeei

发明人： Majid Foodeei

IPC分类号： G01L1904

CPC分类号： G10L19/083

摘要： In methods and apparatus for encoding a gain parameter in a generalized linear predictive analysis-by-synthesis (GLPAS) coder, a subframe gain parameter is determined for each of a plurality of successive subframes of a frame, and a quantized frame gain parameter is determined for each frame using a delayed decision quantizer operating on the subframe gain parameters. The subframe gain parameters may be treated as components of a gain vector and the gain vector may be vector quantized to determine the quantized frame gain parameter. Encoder parameters are efficiently aligned with decoder parameters to ensure proper end-to-end operation. Alternatively, tree quantization or trellis quantization may be applied to the subframe gain parameters to determine the quantized frame gain parameter. The methods and apparatus are particularly applicable to low bit rate speech coding.

摘要翻译： 在广义线性预测分析合成（GLPAS）编码器中对增益参数进行编码的方法和装置中，为帧的多个连续子帧中的每一个确定子帧增益参数，并且确定量化帧增益参数 对于每个帧，使用对子帧增益​​参数进行操作的延迟判定量化器。 子帧增益参数可以被视为增益矢量的分量，并且增益矢量可以被矢量量化以确定量化帧增益参数。 编码器参数与解码器参数有效对齐，以确保正确的端到端操作。 或者，可以将树量化或网格量化应用于子帧增益参数以确定量化帧增益参数。 该方法和装置特别适用于低比特率语音编码。

公开(公告)号：US6011846A

公开(公告)日：2000-01-04

申请号：US881062

申请日：1997-06-24

申请人： Rafi Rabipour ,  Dominic Ho ,  Majid Foodeei ,  Madeleine Saikaly

发明人： Rafi Rabipour ,  Dominic Ho ,  Majid Foodeei ,  Madeleine Saikaly

IPC分类号： G10L21/02 ,  H04B3/20 ,  H04B7/015 ,  G10L9/00

CPC分类号： H04B7/015 ,  H04B3/20 ,  G10L2021/02082

摘要： In methods and apparatus for suppressing echo of a far end signal encoded using LPC-based compression in a near end signal encoded using LPC-based compression, parameters of each frame of the near end encoded signal are processed without synthesizing a speech signal from the near end encoded signal to determine whether sufficient echo to merit echo suppression is present in the frame. Upon determining that insufficient echo to merit echo suppression is present in the frame, the parameters of the frame are passed unmodified. Upon determining that sufficient echo to merit echo suppression is present in said frame, the parameters of the frame are modified without synthesizing a speech signal to suppress echo in the frame. The methods and apparatus are particularly suitable in codec bypass applications.

摘要翻译： 在使用基于LPC的压缩编码的近端信号中抑制使用基于LPC的压缩编码的远端信号的回波的方法和装置中，处理近端编码信号的每帧的参数，而不从近端 结束编码信号以确定帧中是否存在足以有效回波抑制的回波。 在确定帧中存在不足以获得回波抑制的回波的情况下，帧的参数未被修改。 在确定在所述帧中存在足够的回波以获得回波抑制的情况下，修改帧的参数而不合成语音信号以抑制帧中的回波。 该方法和装置特别适用于编解码器旁路应用。

公开(公告)号：US06445696B1

公开(公告)日：2002-09-03

申请号：US09513667

申请日：2000-02-25

申请人： Majid Foodeei ,  Anthony E. Raetz

发明人： Majid Foodeei ,  Anthony E. Raetz

IPC分类号： H04J324

CPC分类号： H04Q11/0478 ,  H04L2012/5656 ,  H04L2012/5671

摘要： The invention uses an ATM Adaptation Layer of type 2 (AAL2) standard mechanism to define efficient support for Variable Rate Coding (VRC). The VRC in this context typically refers to codecs, which adapt their rate to information content variations in speech and audio. Such VRC results in lower average rate than the constant rate codecs or use of constant rate codecs coupled with silence suppression (SS), currently deployed in voice over ATM schemes using AAL2. Possible ATM transport, trunking and access applications encompass both Circuit Emulation Services (CES) and Local Loop Emulation Services (LLES). A typical VRC profile encompasses options for all sub-rates within one or more VRC standard or proprietary variable rate codec. The output of a rate determination algorithm (RDA), commonly part of variable rate codec, is fed into present AAL2 inter-working function (IWF). The IWF in AAL2, which normally supports SS or multiple rates (as opposed to voice content VRC), is extended to accommodate VRC and thereafter automatically furnishes AAL2 capabilities with extensions to VRC. As AAL2 standard capability is extended to VRC, all other advantages of AAL2 and Voice over ATM, including channel multiplexing, idle channel suppression, and alternative signaling methods, are maintained and leveraged. A simple mapping of frame number in a typical VRC speech codec into AAL2 sequence number is employed. This allows for easy use of available error concealment techniques based on frame error, already part of VRC codec standards such as Enhanced VRC (EVRC). When using tandem-free-operation (TFO) of VRC-ATM, higher end-to-end voice quality and bandwidth efficiency can be provided. More advanced capabilities can provide TFO VRC across access and transport networks involving ATM.

摘要翻译： 本发明使用类型2（AAL2）标准机制的ATM适配层来定义对可变速率编码（VRC）的有效支持。 在这种情况下，VRC通常是指编解码器，其将其速率适应于语音和音频中的信息内容变化。 这种VRC的平均速率比恒定速率编解码器或使用恒定速率编解码器加上静音抑制（SS）的平均速率低，目前部署在使用AAL2的ATM方案中。 可能的ATM运输，中继和接入应用包括电路仿真服务（CES）和本地环路仿真服务（LLES）。 典型的VRC配置文件包含一个或多个VRC标准或专有可变速率编解码器中所有子速率的选项。 通常是可变速率编解码器的一部分的速率确定算法（RDA）的输出被馈送到当前的AAL2互通功能（IWF）中。 通常支持SS或多个速率（而不是语音内容VRC）的AAL2中的IWF被扩展以适应VRC，此后自动提供具有扩展到VRC的AAL2功能。 由于AAL2标准能力扩展到VRC，维护和利用了AAL2和ATM之间的所有其他优点，包括信道复用，空闲信道抑制和替代信令方法。 采用典型VRC语音编解码器中帧号简单映射为AAL2序列号。 这允许容易地使用基于帧错误的可用的错误隐藏技术，这已经是VRC编解码器标准（例如增强型VRC（EVRC））的一部分。 当使用VRC-ATM的无串行操作（TFO）时，可以提供更高的端到端语音质量和带宽效率。 更先进的功能可以在涉及ATM的接入和传输网络中提供TFO VRC。

公开(公告)号：US5943645A

公开(公告)日：1999-08-24

申请号：US847527

申请日：1997-04-24

申请人： Dominic Ho ,  Rafi Rabipour ,  Majid Foodeei

发明人： Dominic Ho ,  Rafi Rabipour ,  Majid Foodeei

IPC分类号： H04B3/20 ,  H04M9/08

CPC分类号： H04B3/20

摘要： In methods and apparatus for computing measures of echo of a far end signal in a near end signal, the evolution over time of frequency spectra of the near end and far end signals are compared to compute a measure of the echo. A far end spectrum of the far end signal and a near end spectrum of the near end signal are determined for each of a plurality of successive time intervals. A respective measure of correlation is determined for each of a plurality of spectrum pairs, each spectrum pair comprising a respective near end spectrum and a respective far end spectrum, the far end spectrum corresponding to a time interval which lags a time interval corresponding to the near end spectrum by a respective time lag. The measures of correlation are compared to determine a maximum measure of correlation which can be used as a measure of echo. The echo measure computation technique is particularly suitable for use in echo suppressors for digital cellular telephony systems, but has other applications.

摘要翻译： 在近端信号中用于计算远端信号的回波测量的方法和装置中，比较近端和远端信号的频谱随着时间的演变，以计算回波的测量。 为多个连续时间间隔中的每一个确定远端信号的远端频谱和近端信号的近端频谱。 对于多个频谱对中的每一个确定相关的相关度量，每个频谱对包括相应的近端频谱和相应的远端频谱，远端频谱对应于滞后于与近距离对应的时间间隔的时间间隔 结束频谱由相应的时间延迟。 比较相关度的方法来确定可用作回波测量值的最大相关度量度。 回波测量计算技术特别适用于数字蜂窝电话系统的回波抑制器，但具有其他应用。