公开(公告)号：US4987375A

公开(公告)日：1991-01-22

申请号：US480384

申请日：1990-02-15

Applicant: Kuang-Tsan Wu ,  John D. McNicol

Inventor： Kuang-Tsan Wu ,  John D. McNicol

IPC: H04L27/38

CPC classification number: H04L27/3818 ,  Y10S331/02

Abstract: A carrier lock detector for a quadrature amplitude modulation system includes Exclusive-OR gating circuits for determining when detected signal points occur within first areas centered on signal point positions in a phase plane diagram or second areas between the signal point positions, and for producing corresponding output signals. An integrated difference between these output signals is produced by an integrator and compared with a threshold level to provide a carrier lock detection signal. The arrangement is such that the integrated difference is substantially zero when the carrier is unlocked, so that the threshold level can be set to a low value to enable reliable operation of the detector at low signal-to-noise ratios.

Abstract translation: 用于正交幅度调制系统的载波锁定检测器包括异或门控电路，用于确定检测到的信号点何时出现在以相平面图中的信号点位置为中心的第一区域或信号点位置之间的第二区域中，并产生相应的输出 信号。 这些输出信号之间的积分差异由积分器产生并与阈值电平进行比较以提供载波锁定检测信号。 该布置使得当载体被解锁时，积分差异基本上为零，使得阈值电平可以被设置为低值，以使得能够以较低的信噪比对检测器进行可靠的操作。

公开(公告)号：US4466134A

公开(公告)日：1984-08-14

申请号：US373036

申请日：1982-04-29

Applicant: John D. McNicol

Inventor： John D. McNicol

IPC: H04B3/06 ,  H04B7/005 ,  H04J11/00 ,  H04B1/10 ,  H03H7/03

CPC classification number: H04B7/005

Abstract: In a microwave digital radio transmission system receiver in which a modulated carrier wave is converted to an I.F. signal which is demodulated to produce phase quadrature signals, an apparent frequency error of the carrier wave is detected from the phase quadrature signals and used to control means, such as an I.F. amplitude equalizer, for compensating for amplitude slope of the I.F. signal. A control signal is produced by low pass filtering a product of one phase quadrature signal with the time differential of the other, or the difference between the products of each phase quadrature signal with the time differential of the respective other phase quadrature signal.

Abstract translation: 在其中调制载波被转换成I.F的微波数字无线电传输系统接收机中。 信号，其被解调以产生相位正交信号，从相位正交信号中检测载波的视在频率​​误差，并用于诸如I.F.的控制装置。 幅度均衡器，用于补偿I.F.的幅度斜率。 信号。 通过对一相正交信号的乘积与另一相位的时间差进行低通滤波，或每相位正交信号的乘积之差与各自的其他相位正交信号的时间差进行低通滤波，产生控制信号。