公开(公告)号：US5381143A

公开(公告)日：1995-01-10

申请号：US118495

申请日：1993-09-08

申请人： Osamu Shimoyoshi ,  Kenzo Akagiri ,  Miki Abe ,  Takahiro Watanabe

发明人： Osamu Shimoyoshi ,  Kenzo Akagiri ,  Miki Abe ,  Takahiro Watanabe

IPC分类号： G10L19/02 ,  H03M7/30 ,  H04B14/04 ,  H04N19/115 ,  H04N19/119 ,  H04N19/124 ,  H04N19/132 ,  H04N19/134 ,  H04N19/136 ,  H04N19/146 ,  H04N19/169 ,  H04N19/189 ,  H04N19/196 ,  H04N19/42 ,  H04N19/423 ,  H04N19/46 ,  H04N19/60 ,  H04N19/625 ,  H04N19/635 ,  H04N19/70 ,  H04N19/80 ,  H04N19/85 ,  H03M7/00

CPC分类号： H04B14/046

摘要： A digital signal processing system comprising a compressor, an expander and a scale-down circuit. The compressor includes non-block frequency analyzer that frequency analyzes the digital input digital signal, without dividing it into block, to provide a frequency range signal in each of plural frequency ranges. A block frequency analyzer divides the frequency range signals into blocks and performs a block frequency analysis of each block of the frequency range signals to provide a block of spectral coefficients. A quantizer quantizes the block of spectral coefficients from the block frequency analyzer to provide a block of a compressed signal. The expander includes a block frequency synthesizer that performs a block frequency synthesis to transform, from the frequency domain to the time domain, the spectral coefficients in each of the frequency ranges in each block of the compressed signal to provide, in each of the frequency ranges, a block of a reproduced frequency range signal. A non-block frequency synthesizer synthesizes the reproduced frequency range signals, without dividing them into blocks, to provide the digital output signal. Finally, the system includes a scale-down circuit that scales down values in the block frequency analysis performed by the block frequency analyzer or the block frequency synthesis performed by the block frequency synthesizer. The scale-down circuit operates to cause the noise levels resulting from scaling down the values to be different in each of the frequency ranges.

摘要翻译： 一种数字信号处理系统，包括压缩器，扩展器和缩小电路。 压缩机包括非块频率分析仪，其频率分析数字输入数字信号，而不将其分成块，以在多个频率范围中的每一个中提供频率范围信号。 块频率分析仪将频率范围信号划分为块，并对频率范围信号的每个块执行块频率分析，以提供频谱系数块。 量化器对来自块频率分析器的频谱系数块进行量化以提供压缩信号的块。 扩展器包括块频率合成器，其执行块频率合成以从频域到时域将压缩信号的每个块中的每个频率范围中的频谱系数变换以在每个频率范围 ，再现频率范围信号的块。 非块频率合成器将再现的频率范围信号合成，而不将它们分成块，以提供数字输出信号。 最后，该系统包括一个缩小电路，其缩小由块频率分析器执行的块频率分析中的值或由块频率合成器执行的块频率合成。 降压电路用于使得在每个频率范围内将值缩小而导致的噪声水平不同。

公开(公告)号：US4573039A

公开(公告)日：1986-02-25

申请号：US432845

申请日：1982-10-05

申请人： Tadao Suzuki ,  Miki Abe

发明人： Tadao Suzuki ,  Miki Abe

IPC分类号： H03M1/82 ,  G11B20/10 ,  H03M1/00 ,  H03M1/66 ,  H03K13/20

CPC分类号： H03M1/662 ,  H03M1/68 ,  H03M1/82

摘要： A digital to analog converter for converting alternately supplied first and second channel digital data words to first and second channel analog output signals comprises a current producing circuit for selectively producing currents corresponding to the digital data words, respectively; first and second channel voltage producing circuits for producing the first and second channel analog output signals in response to the currents from the current producing circuit; and a switch disposed between the current producing circuits and the first and second channel voltage producing circuits for selectively supplying the current corresponding to the first channel digital data word to the first channel voltage producing circuit and the current corresponding to the second channel digital data word to the second channel voltage producing circuit.

摘要翻译： 用于将交替提供的第一和第二通道数字数据字转换为第一和第二通道模拟输出信号的数模转换器包括分别用于选择性地产生对应于数字数据字的电流的电流产生电路; 第一和第二通道电压产生电路，用于响应于来自电流产生电路的电流产生第一和第二通道模拟输出信号; 以及设置在电流产生电路和第一和第二通道电压产生电路之间的开关，用于选择性地将对应于第一通道数字数据字的电流提供给第一通道电压产生电路和对应于第二通道数字数据字的电流 第二通道电压产生电路。

公开(公告)号：US4458208A

公开(公告)日：1984-07-03

申请号：US367213

申请日：1982-04-09

申请人： Miki Abe

发明人： Miki Abe

IPC分类号： H03F1/00 ,  H03F1/30 ,  H03F3/20 ,  H03F3/217 ,  H03K7/08 ,  H03F3/16

CPC分类号： H03F3/217 ,  H03F1/305

摘要： A pulse width modulated signal amplifier includes a power source, an integrator supplied with an input signal to be pulse-width-modulated and a carrier signal from a carrier signal oscillator, a comparator connected to the output of the integrator for producing a pulse width modulated signal, an output amplifier supplied with a DC voltage from the power source, and a negative feedback circuit connected between the input of the integrator and the output of the output amplifier. The negative feedback circuit becomes effective after a predetermined time from the time when the power source becomes ON so as to avoid the oscillation of the closed loop including the integrator.

摘要翻译： 脉宽调制信号放大器包括电源，提供有脉冲宽度调制的输入信号的积分器和来自载波信号振荡器的载波信号，连接到积分器的输出的比较器，用于产生脉宽调制信号 信号，提供有来自电源的直流电压的输出放大器和连接在积分器的输入端和输出放大器的输出端之间的负反馈电路。 负电源反馈电路在从电源接通之后的预定时间起有效，以避免包括积分器的闭环振荡。