Differential coding system
    3.
    发明授权
    Differential coding system 失效
    差分编码系统

    公开(公告)号:US5127022A

    公开(公告)日:1992-06-30

    申请号:US439815

    申请日:1989-11-21

    IPC分类号: H03M3/04

    CPC分类号: H03M7/3044

    摘要: A differential code (DPCM) transmission system for an audio signal, in case higher frequency components thereof are dominant, every another samples of the input signal are alternately into two groups, in each of which differential coding effected, so as to maintain a dynamic range in higher frequency range; when a near instantaneously compressed DPCM signal is transmitted, coding errors caused by the compression are corrected by varying the difference between samples in response to the comparison between a locally decoded signal and the original signal; when the frequency components exceeding one fourth of the sampling frequency are contained in the input signal, successive 3 MSB's having a pattern "1, 0, 1" or "0, 1, 0" are corrected into "1, 1, 1" or "0, 0, 0" respectively; and in case 2 symbols of a tertiary code converted from 3 bits of a binary code are transmitted and restored, peripheral bit arrangement of a matrix having rows consisting of the first symbols of the converted tertiary codes and columns consisting of the second symbols thereof are allotted such as Gray codes are obtained, while an inner 2.times.2 matrix of a 4.times. 4 matrix formed by inserting a new threshold level between two threshold levels provided for detecting the tertiary code is allocated with bits relating to bits arranged at adjacent positions, so as to reduce the bit error rate of the restored binary code.

    摘要翻译: 用于音频信号的差分码(DPCM)传输系统,在其较高频率分量占优势的情况下,输入信号的每隔一个样本交替地分成两组,每个采样进行差分编码,以保持动态范围 在较高的频率范围内; 当发送近瞬时压缩的DPCM信号时,通过响应于本地解码信号与原始信号之间的比较改变样本之间的差异来校正由压缩引起的编码错误; 当超过采样频率四分之一的频率分量包含在输入信号中时,将具有模式“1,0,1”或“0,1,0”的连续3个MSB被校正为“1,1,1”或 “0,0,0” 并且在发送和恢复从二进制码的3位转换的三级代码的2个符号的情况下,分配具有由转换的第三代码的第一符号组成的行的矩阵的周边比特排列以及由其第二个符号组成的列 获得格雷码,而通过在提供用于检测第三代码的两个阈值电平之间插入新的阈值电平而形成的4×4矩阵的内部2×2矩阵被分配与位于相邻位置的位有关的位,以便减少 恢复的二进制码的误码率。

    Differential code transmission system
    4.
    发明授权
    Differential code transmission system 失效
    差分码传输系统

    公开(公告)号:US5228059A

    公开(公告)日:1993-07-13

    申请号:US832587

    申请日:1992-02-07

    IPC分类号: H03M3/04 H04L25/34

    CPC分类号: H03M7/3044 H04B14/066

    摘要: As to a differential code (DPCM) transmission system for an input signal as such as an audio signal, in case higher frequency components thereof are dominant, every another samples of the input signal are alternately into two groups, in each of which differential coding effected, so as to maintain a dynamic range in higher frequency range; in case no frequency components exceeding one fourth of the sampling frequency are contained in the input signal, successive 3 MSB's having a pattern "1, 0, 1" or "0, 1, 0" are corrected into "1, 1, 1" or "0, 0, 0" respectively; and in case 2 symbols of a tertiary code converted from 3 bits of a binary code are transmitted and restored, peripheral bit arrangement of a matrix having rows consisting of the first symbols of the converted tertiary codes and columns consisting of the second symbols thereof are allotted such as Gray codes are obtained, while an inner 2.times.2 matrix of a 4.times.4 matrix formed by inserting a new threshold level between two threshold levels provided for detecting the tertiary code is allotted with bits relating to bits arranged at adjacent positions, so as to reduce the bit error rate of the restored binary code.

    摘要翻译: 对于用于诸如音频信号的输入信号的差分码(DPCM)传输系统,如果其较高频率分量占优势,则输入信号的每隔一个样本交替地分成两组,每一个采样差分编码 ,以保持较高频率范围内的动态范围; 在输入信号中不包含超过采样频率四分之一的频率分量的情况下,具有模式“1,0”或“0,1,0”的连续3个MSB被校正为“1,1,1” 或“0,0,0” 并且在发送和恢复从二进制码的3位转换的三级代码的2个符号的情况下,分配具有由转换的第三代码的第一符号组成的行的矩阵的周边比特排列以及由其第二个符号组成的列 例如格雷码,而通过在提供用于检测第三代码的两个阈值电平之间插入新的阈值电平形成的4×4矩阵的内部2×2矩阵被分配有与布置在相邻位置的位有关的位,以便减少 恢复的二进制码的误码率。

    Apparatus for demodulating AM data multiplexed modulated wave signal
    5.
    发明授权
    Apparatus for demodulating AM data multiplexed modulated wave signal 失效
    用于解调AM数据多路复用调制波信号的装置

    公开(公告)号:US5970046A

    公开(公告)日:1999-10-19

    申请号:US889575

    申请日:1997-07-08

    IPC分类号: H04B1/04 H04B1/30 H04J11/00

    CPC分类号: H04B1/04 H04B1/30

    摘要: An apparatus for demodulating an AM data multiplexed modulated wave signal in which an analog modulated signal and digital modulated signals are multiplexed, in order to derive therefrom a baseband digital signal. The demodulation apparatus aims to derive the digital baseband signal from the AM data multiplexed modulated wave signal in which the analog modulated signal obtained by amplitude modulating a carrier having a frequency fc with an analog signal and the digital modulated signals at frequency position of (fc+f.alpha.) and (fc-f.alpha.) line-symmetrical with respect to a frequency axis of the frequency fc are multiplexed. A demodulation apparatus includes an AM type modulated wave signal eliminating circuit for removing an AM modulated wave signal from an input AM data multiplexed modulated wave signal, and a data demodulation circuit for receiving an output of the AM type modulated wave signal eliminating circuit and for deriving therefrom a baseband digital signal.

    摘要翻译: 一种用于解调其中模拟调制信号和数字调制信号被多路复用的AM数据复用调制波信号的装置,以便从中得到基带数字信号。 解调装置旨在从AM数据复用调制波信号导出数字基带信号,其中通过对具有模拟信号的频率fc的载波进行幅度调制而获得的模拟调制信号和频率位置处的(fc + fα)和(fc-fα)相对于频率fc的频率轴线对称的多路复用。 解调装置包括:AM型调制波信号消除电路,用于从输入的AM数据复用调制波信号中去除AM调制波信号;以及数据解调电路,用于接收AM型调制波信号消除电路的输出, 从而提供基带数字信号。

    AM data multiplexing modulation apparatus
    6.
    发明授权
    AM data multiplexing modulation apparatus 失效
    AM数据复用调制装置

    公开(公告)号:US5940365A

    公开(公告)日:1999-08-17

    申请号:US870016

    申请日:1997-06-05

    CPC分类号: H04H20/36 H04L5/06

    摘要: An AM data multiplexing modulation apparatus for multiplexing a digital signal to an AM modulation signal without adversely affecting an AM sync detection output even if AM sync detection is performed. An AM modulator AM modulates a carrier having a frequency fc by an input signal, an orthogonal modulator 3 orthogonally modulates a carrier having a frequency (fc+f.alpha.) by a QPSK baseband digital signal generated by a QPSK baseband digital signal generator 2, a sign inverter and a complex conjugate unit change the sign of a signal having the same phase as a reference carrier of vector shift and corresponding to a dibit formed by the QPSK baseband digital signal generated by the QPSK baseband digital signal generator, another orthogonal modulator orthogonally modulates a carrier having a frequency (fc-f.alpha.) by an output of the complex conjugate unit, the outputs of the two orthogonal modulators are added by an adder, this addition result is added to the output of the AM modulator by another adder which outputs an AM data multiplexing modulation output.

    摘要翻译: 一种AM数据多路复用调制装置,即使执行AM同步检测,也将数字信号复用到AM调制信号,而不会对AM同步检测输出产生不利影响。 AM调制器AM通过输入信号调制具有频率fc的载波,正交调制器3通过由QPSK基带数字信号发生器2产生的QPSK基带数字信号对频率(fc +fα1)进行正交调制, 符号反相器和复共轭单元改变与矢量移位的参考载波具有相同相位的信号的符号,并且对应于由QPSK基带数字信号发生器产生的QPSK基带数字信号形成的二进制,另一个正交调制器正交调制 通过复共轭单元的输出具有频率(fc-fα)的载波,两个正交调制器的输出由加法器相加,该相加结果通过另一个加法器相加到另一加法器的输出 AM数据复用调制输出。

    AM multiplexing broadcast apparatus
    7.
    发明授权
    AM multiplexing broadcast apparatus 失效
    AM复用广播装置

    公开(公告)号:US5943345A

    公开(公告)日:1999-08-24

    申请号:US949695

    申请日:1997-10-14

    摘要: An AM multiplexing broadcast apparatus multiplexes a digital modulated signal independent of an AM modulated signal, in the same frequency band as the AM modulated signal. A sum signal is amplified by a first amplifier. An inverse of the sum signal is obtained by an inverse calculator. A divider divides this inverse signal by a magnification factor of the first amplifier. An output of the divider and a digital modulated signal in the same frequency band as an AM modulated signal are multiplied by a first multiplier. A carrier generated by a carrier generator is phase-modulated by a phase modulator. Outputs of the phase modulator and first multiplier are synthesized and thereafter amplified by a second amplifier. Outputs of the first and second amplifiers are multiplied by a second multiplier and transmitted from an antenna.

    摘要翻译: AM复用广播装置在与AM调制信号相同的频带中复用与AM调制信号无关的数字调制信号。 和信号由第一放大器放大。 通过逆计算器获得和信号的反相。 分频器将该反相信号除以第一放大器的放大系数。 分频器的输出和与AM调制信号相同频带的数字调制信号乘以第一乘法器。 由载波发生器产生的载波由相位调制器进行相位调制。 合成相位调制器和第一乘法器的输出,然后由第二放大器放大。 第一和第二放大器的输出乘以第二乘法器并从天线发送。