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1.发明授权公开(公告)号：US06772114B1
公开(公告)日：2004-08-03
申请号：US09710916
申请日：2000-11-13
IPC分类号： G10L1900
CPC分类号： G10L19/0208
摘要： In an audio transmission system, an input signal is split up into two spectral portions in a transmitter. These spectral portions are coded by their own respective coder. The low-frequency signal portion is coded by a regular narrow-band coder and the high frequency portion is coded using a coder that outputs LPC codes and signal amplitude codes. In the receiver, the low frequency signal portion is reconstructed by a narrow-band decoder and the high frequency portion is reconstructed by applying a high pass filter to a white noise signal and applying an LPC filter that is controlled by the LPC codes to this filtered white noise signal and adjusting the signal amplitude with an amplifier that is controlled using the amplitude codes of the transmitter. The reconstructed low frequency signal and the reconstructed high frequency signal are then combined to yield a reconstructed output signal containing both frequency ranges.
摘要翻译： 在音频传输系统中，输入信号在发射机中被分成两个频谱部分。 这些频谱部分由其各自的编码器编码。 低频信号部分由常规窄带编码器编码，并且使用输出LPC码和信号幅度码的编码器对高频部分进行编码。 在接收机中，低频信号部分由窄带解码器重构，高频部分通过对白噪声信号施加高通滤波器并将由LPC码控制的LPC滤波器应用于该滤波器 白噪声信号，并用放大器调节信号幅度，该放大器使用发射机的幅度码进行控制。 然后将重构的低频信号和重建的高频信号组合以产生包含两个频率范围的重构输出信号。
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公开(公告)号：US07346499B2
公开(公告)日：2008-03-18
申请号：US10169497
申请日：2001-11-09
IPC分类号： G10L21/00
CPC分类号： G10L21/0364 , G10L25/24
摘要： Wideband extension of telephone speech for higher perceptual quality. A method for extending the frequency range of a speech signal using wideband extension method with an inverse filter and a synthesis filter where both filters receive LPC coefficients from an LPC estimator. The wideband LPC coefficients are obtained from wideband LSFs. The wideband LSFs are obtained by appending highband LSFs, created by applying a matrix to narrowband LSFs, and lowband LSFs, created by dividing the narrowband LSFs by two. The matrix used to create the highband LSFs is selected from a predetermined list of matrices. The selection is based on either wideband or narrowband reflection coefficients extracted from the narrowband speech signal.
摘要翻译： 宽带扩展电话语音，提高感知质量。 一种使用宽带扩展方法用反向滤波器和合成滤波器扩展语音信号的频率范围的方法，其中两个滤波器从LPC估计器接收LPC系数。 从宽带LSF获得宽带LPC系数。 通过将通过将窄带LSF应用矩阵创建的高频LSF和通过将窄带LSF除以2而创建的低频LSF来获得宽带LSF。 用于创建高频LSF的矩阵从预定的矩阵列表中选择。 该选择基于从窄带语音信号提取的宽带或窄带反射系数。
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公开(公告)号：US07174135B2
公开(公告)日：2007-02-06
申请号：US10480660
申请日：2002-06-20
CPC分类号： G10L21/038
摘要： Described is a transmission system (10) comprising a transmitter (12) for transmitting a narrowband audio signal to a receiver (14) via a transmission channel (16). The receiver (14) comprises a frequency domain bandwidth extender (18) for extending a bandwidth of the received narrowband audio signal by complementing the received narrowband audio signal with a highband extension thereof. The bandwidth extender (18) comprises an amplitude extender (24) for extending the bandwidth of an amplitude spectrum of the received narrowband audio signal by mapping narrowband amplitudes onto highband amplitudes. The bandwidth extender (18) further comprises a phase extender (26) for extending the bandwidth of a phase spectrum of the received narrowband signal and a combiner (28) for combining the extended amplitude spectrum and the extended phase spectrum into a bandwidth extended audio signal. The transmission system (10) is characterized in that the amplitude extender (24) comprises an amplitude mapper (42) and first and second frequency scale transformers (40,44). The first frequency scale transformer. (40) is arranged for transforming a linear frequency scale of the amplitude spectrum into a logarithmic frequency scale, e.g. the Bark scale. The amplitude mapper (42) is arranged for mapping according to the logarithmic frequency scale the narrowband amplitudes onto the highband amplitudes. The second frequency scale transformer (44) is arranged for transforming the logarithmic frequency scale of the extended amplitude spectrum into the linear frequency scale.
摘要翻译： 描述了一种传输系统（10），包括用于经由传输信道（16）将窄带音频信号发送到接收机（14）的发射机（12）。 接收器（14）包括频域带宽扩展器（18），用于通过用接收的窄带音频信号的高频扩展来补充接收到的窄带音频信号来扩展接收的窄带音频信号的带宽。 带宽扩展器（18）包括幅度扩展器（24），用于通过将窄带幅度映射到高频带幅度上来扩展接收的窄带音频信号的幅度谱带宽。 带宽扩展器（18）还包括扩展器（26），用于扩展所接收的窄带信号的相位频带的带宽;以及组合器（28），用于将扩展幅度频谱和扩展相位频谱组合成带宽扩展音频信号 。 传输系统（10）的特征在于，幅度扩展器（24）包括幅度映射器（42）和第一和第二频率比例变换器（40,44）。 第一台变频器。 （40）被布置用于将幅度谱的线性频率变换变换成对数频率标度，例如。 吠声鳞片。 幅度映射器（42）被布置用于根据对数频率标度将窄带幅度映射到高频带幅度上。 第二频率比例变换器（44）被设置为将扩展振幅频谱的对数频谱变换为线性频率标度。
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