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    APPARATUS FOR PERFORMING FREQUENCY CONVERSION IN A COMMUNICATION SYSTEM
    1.
    发明公开
    APPARATUS FOR PERFORMING FREQUENCY CONVERSION IN A COMMUNICATION SYSTEM 失效
    在EINER TELEKOMMUNIKATIONSANORDNUNG的FREQUENZUMSETZER

    公开(公告)号：EP0716788A4

    公开(公告)日：1996-11-06

    申请号：EP95922104

    申请日：1995-05-26

    Applicant: MOTOROLA ENERGY SYSTEMS INC

    Inventor： STEWART KENNETH A ,  LOVE ROBERT T

    IPC: H03D3/00 ,  H04B1/26 ,  H04B1/69

    CPC classification number: H04B1/0021 ,  H03D3/007 ,  H03D2200/005 ,  H03D2200/0056 ,  H03D2200/006 ,  H03D2200/0068 ,  H03D2200/0072 ,  H03D2200/008 ,  H04B1/0003 ,  H04B1/0032 ,  H04B1/0046 ,  H04B1/26

    Abstract: An efficient apparatus for performing frequency conversion from a final IF frequency to a baseband frequency is described. A counter (401) generates two logical signals G1 (402) and G2 (403) which are passed to an exclusive-OR gate (404) and a multiplexer (406). When a control signal (411) is deasserted, multiplexer (406) passes signal G1 to I1 and signal G2 to I2; when control signal (411) is asserted, multiplexer (406) passes binary signal G1 to I2 (410) and signal G2 to I1 (407). Similarly, multiplexer (405) swaps its input real and imaginary samples when the output of exclusive-OR gate (404) is asserted; otherwise, it performs no operation on its input samples. Signals I1 (407) and I2 (410) are used to control arithmetic inverters (408) and (409) respectively. When the controlling signal for either inverter is asserted, the inventer performs arithmetic inversion, otherwise it performs no operation.

    Abstract translation: 描述了用于执行从最终IF频率到基带频率的频率转换的有效设备。 计数器（401）产生传送到异或门（404）和多路复用器（406）的两个逻辑信号G1（402）和G2（403）。 当控制信号（411）无效时，多路复用器（406）将信号G1传递给I1并将信号G2传递给I2; 当控制信号（411）被断言时，多路复用器（406）将二进制信号G1传递给I2（410）并将信号G2传递给I1（407）。 类似地，当异或门（404）的输出被声明时，多路复用器（405）交换其输入实数和虚数样本; 否则，它不会对其输入采样执行任何操作。 信号I1（407）和I2（410）分别用于控制算术逆变器（408）和（409）。 当任一个逆变器的控制信号有效时，本发明人执行算术逆变，否则它不执行任何操作。

    Digitaler Demodulator frequenzmodulierter Signale
    4.
    发明公开
    Digitaler Demodulator frequenzmodulierter Signale 失效
    频率调制的信号的数字解调器。

    公开(公告)号：EP0080014A2

    公开(公告)日：1983-06-01

    申请号：EP82105412.9

    申请日：1982-06-21

    Applicant: ROBERT BOSCH GMBH

    Inventor： Kammeyer, Karl-Dirk, Dr.-Ing.

    IPC: H03D3/00

    CPC classification number: H03D3/007 ,  H03B27/00 ,  H03B28/00 ,  H03D3/006 ,  H03D3/02 ,  H03D2200/0035 ,  H03D2200/005 ,  H03D2200/006 ,  H03D2200/008

    Abstract: Es wird ein rein digitaler Demodulator für frequenzmodulierte Signale vorgeschlagen, der insbesondere zur Demodulation von UKW-Rundfunksignalen geeignet ist. Zur Herausfilterung des ausgewählten Kanals aus dem Zwischenfrequenzsignal werden nichtrekursive Systeme benützt, die eine lineare Phase aufweisen. Phasenverzerrungen der frequenzmodulierten Signale werden somit vollständig vermieden. Das Zwischenfrequenzsignal wird in den Basisband-Bereich transformiert. Das niederfrequente Nutzsignal wird durch einen digitalen Demodulationsalgorithmus erzielt.

    Abstract translation: 公开了一种用于频率调制的信号一个纯粹的数字解调器，这是特别适合于FM广播信号的解调。 用于从该中频信号的非递归系统的使用，其具有线性相位滤除所述选择的信道的。 频率调制的信号的相位失真由此完全避免。 该中频信号被变换到基带范围内。 低频有用信号由数字解调算法获得。

    FM-demodulating apparatus
    6.
    发明公开
    FM-demodulating apparatus 失效
    FM调制装置

    公开(公告)号：EP0399758A3

    公开(公告)日：1992-03-25

    申请号：EP90305485.6

    申请日：1990-05-21

    Applicant: SONY CORPORATION

    Inventor： Sakamoto, Etsurou

    IPC: H03D3/04 ,  H04N5/91

    CPC classification number: H03D3/007 ,  H03D3/006 ,  H03D2200/0062 ,  H03D2200/008 ,  H04N5/911 ,  H04N5/93

    Abstract: An FM-demodulating apparatus for use in a video tape recorder or the like arranged such that an FM-modulated video signal is phase-shifted by utilising a Hilbert transform circuit thereby to reduce the occurrence of moire. Thus, a signal-to-noise (S/N) ratio of a demodulated signal can be improved. In one embodiment, the apparatus comprises a first demodulator circuit (13) receiving an FM-modulated input; a Hilbert transform circuit (15) receiving the FM-modulated signal for phase-shifting it by 90 degrees; a second demodulator circuit (16) coupled to said Hilbert transform circuit (15); and mixing means (17) coupled to said first demodulator circuit (13) and said second demodulator circuit (16) for deriving FM-demodulated video signals. In a second embodiment, the apparatus comprises a Hilbert transform circuit (62, 63, 65) receiving the FM-modulated signal for phase-shifting it by 90 degrees, said Hilbert transform circuit including delay circuits (62, 63) and a subtracting circuit (65); adding means (64) coupled to said delay circuits (62, 63) included in said Hilbert transform circuit; a first demodulator circuit (67) coupled to said adding means (64) for demodulating signals obtained from said adding means (64); a second demodulating circuit (69) coupled to said subtracting circuit (65) of the Hilbert transform circuit for demodulating signals obtained from said subtracting circuit (65); and a mixing circuit (70) coupled to said adding means and said subtracting circuit of said Hilbert transform circuit for deriving FM-demodulated video signals.

    FM-demodulating apparatus
    10.
    发明公开
    FM-demodulating apparatus 失效
    FM-解调器。

    公开(公告)号：EP0399758A2

    公开(公告)日：1990-11-28

    申请号：EP90305485.6

    申请日：1990-05-21

    Applicant: SONY CORPORATION

    Inventor： Sakamoto, Etsurou

    IPC: H03D3/04 ,  H04N5/91

    CPC classification number: H03D3/007 ,  H03D3/006 ,  H03D2200/0062 ,  H03D2200/008 ,  H04N5/911 ,  H04N5/93

    Abstract: An FM-demodulating apparatus for use in a video tape recorder or the like arranged such that an FM-modulated video signal is phase-shifted by utilising a Hilbert transform circuit thereby to reduce the occurrence of moire. Thus, a signal-to-noise (S/N) ratio of a demodulated signal can be improved.
    In one embodiment, the apparatus comprises a first demodulator circuit (13) receiving an FM-modulated input; a Hilbert transform circuit (15) receiving the FM-modulated signal for phase-shifting it by 90 degrees; a second demodulator circuit (16) coupled to said Hilbert transform circuit (15); and mixing means (17) coupled to said first demodulator circuit (13) and said second demodulator circuit (16) for deriving FM-demodulated video signals.
    In a second embodiment, the apparatus comprises a Hilbert transform circuit (62, 63, 65) receiving the FM-modulated signal for phase-shifting it by 90 degrees, said Hilbert transform circuit including delay circuits (62, 63) and a subtracting circuit (65); adding means (64) coupled to said delay circuits (62, 63) included in said Hilbert transform circuit; a first demodulator circuit (67) coupled to said adding means (64) for demodulating signals obtained from said adding means (64); a second demodulating circuit (69) coupled to said subtracting circuit (65) of the Hilbert transform circuit for demodulating signals obtained from said subtracting circuit (65); and a mixing circuit (70) coupled to said adding means and said subtracting circuit of said Hilbert transform circuit for deriving FM-demodulated video signals.

    Abstract translation: 一种用于录像机等的FM解调装置，被布置为使得FM调制的视频信号通过利用希尔伯特变换电路进行相移，从而减少波纹的发生。 因此，可以提高解调信号的信噪比（S / N）比。 在一个实施例中，该装置包括接收FM调制输入的第一解调器电路（13） 接收FM调制信号的希尔伯特变换电路（15）将其相移90度; 耦合到所述希尔伯特变换电路（15）的第二解调器电路（16）。 以及耦合到所述第一解调器电路（13）和所述第二解调器电路（16）的用于导出FM解调的视频信号的混合装置（17）。 在第二实施例中，所述装置包括接收FM调制信号以将其相移90度的希尔伯特变换电路（62,63,65），所述希尔伯特变换电路包括延迟电路（62,63）和减法电路 （65）; 耦合到包括在所述希尔伯特变换电路中的所述延迟电路（62,63）的加法装置（64） 耦合到所述加法装置（64）的第一解调器电路（67），用于对从所述加法装置（64）获得的信号进行解调; 耦合到希尔伯特变换电路的所述减法电路（65）的第二解调电路（69），用于对从所述减法电路（65）获得的信号进行解调; 以及混合电路（70），耦合到所述加法装置和所述希尔伯特变换电路的所述减法电路，用于导出FM解调的视频信号。

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