发明授权
- 专利标题: Phase/frequency controlled phase shift keyed signal carrier reconstruction circuit
- 专利标题(中): 相位/频率控制相移键控信号载波重建电路
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申请号: US964466申请日: 1978-11-29
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公开(公告)号: US4224575A公开(公告)日: 1980-09-23
- 发明人: William H. Mosley , Lex A. Scott , Robert S. Gordy
- 申请人: William H. Mosley , Lex A. Scott , Robert S. Gordy
- 申请人地址: TX Dallas
- 专利权人: E-Systems, Inc.
- 当前专利权人: E-Systems, Inc.
- 当前专利权人地址: TX Dallas
- 主分类号: H03L7/087
- IPC分类号: H03L7/087 ; H04L7/027 ; H04L27/00 ; H04L27/227 ; H03D3/18 ; H03L7/08
摘要:
A biphase shift keyed modulated carrier is input to an analog delay line having a plurality of sampling taps time spaced along the line. The modulated input carrier is sampled at a rate four times the carrier frequency to produce amplitude samples of the input. The taps of the delay line are divided into two groups comprising alternate tap sets and the amplitude samples of each group are summed for decoding the I and Q channels of a modulated carrier. The summed signal of each of the channels is input to an individual sample and hold circuit which aliases the carrier frequency to baseband. The output of the first sample and hold circuit of each channel is provided to a second sample and hold circuit for the respective channels. The second sample and hold circuit of each channel is clocked at a data rate derived from a bit timing loop. An estimation of the data is produced by each of the second sample and hold circuits with the data produced by the second sample and hold circuit of one channel providing a recovered carrier signal output. Further, the data produced by each of the second sample and hold circuits, after inversion in one line by means of an inverting amplifier, is input to a phase comparator. The output of the phase comparator is filtered and used to drive a voltage controlled oscillator that generates the clock pulses to operate the first sample and hold circuits and also to clock the delay line.
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