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公开(公告)号：US20050001749A1
公开(公告)日：2005-01-06
申请号：US10495538
申请日：2002-10-28
摘要： Sigma-delta modulation is provided, comprising feeding an input signal to a first SDM, subtracting the output of the first SDM from the input signal, filtering the output of the subtracting to obtain a filtered signal, delaying the input signal, adding the filtered signal to the delayed signal, feeding the output of the adder to a second SDM and providing the output of the second SDM. The first SDM in combination with the subtracting and filtering delivers a correction signal which, by adding it to the input signal, reduces the distortion in the second SDM, which second SDM performs in fact the sigma-delta modulation of the device.
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公开(公告)号：US20060182186A1
公开(公告)日：2006-08-17
申请号：US10550339
申请日：2004-03-24
IPC分类号： H04B14/04
CPC分类号： H03G3/002
摘要： A digital volume control device comprises a logic unit for volume control of digital input signals. Successively supplied m-bits words with maximally k bits active, derived from the output signals of or supplied by a volume control (4) with a quantizer (5) element the filtered m-bits workds are passed, however, with only the j most significant active bits of these filtered signals. The noise shaper operates with a frequency that is a k/j-fold of the frequency by which the m-bits words are supplied. An up-sampler (3) is provided for operation frequency adjustment of the filtered m-bits words to the noise shaper. This operation frequency is at least a factor k/j greater than the sample rate of the digital input signals. The control signals for the logic unit are formed by the m-bits words passed by the quantizer.
摘要翻译： 数字音量控制装置包括用于数字输入信号的音量控制的逻辑单元。 连续提供最大k位有效的m位字，由量化器（5）元素的输出信号的输出信号或由量化器（5）元素提供，过滤的m位工作通过，然而，只有最多j个 这些滤波信号的有效位。 噪声整形器以提供m位字的频率的k / j倍的频率工作。 提供了上采样器（3），用于将滤波后的m位字操作频率调整到噪声整形器。 该操作频率至少比数字输入信号的采样速率高k / j。 逻辑单元的控制信号由量化器通过的m位字形成。
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