公开(公告)号：US4673916A

公开(公告)日：1987-06-16

申请号：US475404

申请日：1983-03-15

Applicant: Masatsugu Kitamura ,  Mitsuaki Tanaka ,  Hiroyuki Takekura

Inventor： Masatsugu Kitamura ,  Mitsuaki Tanaka ,  Hiroyuki Takekura

IPC: H03M1/12 ,  G10L19/00 ,  G11B20/10 ,  H03M1/00 ,  H04B14/04 ,  H04M1/65 ,  H03K13/02

CPC classification number: H04M1/6505 ,  G11B20/10527 ,  H03M1/74

Abstract: In a data compression system, a digital signal comprising a series of digital samples and a sampling datum indicating the sampling interval of the digital samples are written into a read-write memory (M2). The digital samples and the associated sampling datum are read out of the memory into first and second digital-to-analog converters (DAC1, DAC2), respectively. The output of the first digital-to-analog converter is applied to a variable frequency low-pass filter (5) to remove the components having frequencies higher than a presettable frequency limit value which is variable as a function of the output of the second digital-to-analog converter so that the cut-off frequency is lower than one-half the sampling frequency to eliminate quantum noise.

Abstract translation: 在数据压缩系统中，包括一系列数字样本的数字信号和指示数字样本的采样间隔的采样数据被写入读写存储器（M2）。 数字采样和相关采样数据分别从存储器读出到第一和第二数模转换器（DAC1，DAC2）。 第一数模转换器的输出被施加到可变频率低通滤波器（5），以去除具有高于可预设频率极限值的频率的分量，该频率限制值作为第二数字 - 模拟转换器 模拟转换器，使得截止频率低于采样频率的一半，以消除量子噪声。

公开(公告)号：US4626827A

公开(公告)日：1986-12-02

申请号：US475405

申请日：1983-03-15

Applicant: Masatsugu Kitamura ,  Mitsuaki Tanaka ,  Hiroyuki Takekura

Inventor： Masatsugu Kitamura ,  Mitsuaki Tanaka ,  Hiroyuki Takekura

IPC: H03M1/00 ,  H04B14/04 ,  H03K13/02

CPC classification number: H03M1/00 ,  H04B14/046 ,  H03M2201/02 ,  H03M2201/162 ,  H03M2201/196 ,  H03M2201/198 ,  H03M2201/20 ,  H03M2201/3115 ,  H03M2201/4105 ,  H03M2201/4135 ,  H03M2201/4225 ,  H03M2201/4233 ,  H03M2201/4262 ,  H03M2201/531 ,  H03M2201/532 ,  H03M2201/534 ,  H03M2201/535 ,  H03M2201/648 ,  H03M2201/712 ,  H03M2201/715 ,  H03M2201/8128 ,  H03M2201/834

Abstract: A data compression system comprises an analog-to-digital converter for quantizing the analog signal at a first sampling frequency into a series of digital samples and a memory for storing the digital samples. A control circuit generates a sampling datum indicating a variable sampling frequency lower than the first sampling frequency as a function of the instantaneous frequency of the analog signal for selecting digital samples from the memory, reads the selected digital samples out of the memory means in response to the sampling datum, and forms the sampling datum and the selected digital samples into a data set. A series of data sets may be transmitted to a receiving end of the system or stored in a recording medium. The sampling datum is used to indicate the point at which the digital sample is converted to a corresponding analog value.

Abstract translation: 数据压缩系统包括用于将第一采样频率的模拟信号量化成一系列数字样本的模数转换器和用于存储数字样本的存储器。 控制电路根据用于从存储器中选择数字样本的模拟信号的瞬时频率的函数产生指示低于第一采样频率的可变采样频率的采样数据，以响应于从存储器装置读出所选择的数字样本 采样数据，并将采样数据和所选择的数字样本组成数据集。 一系列数据集可以传送到系统的接收端或存储在记录介质中。 采样数据用于指示数字采样转换为相应模拟值的点。