发明授权
- 专利标题: Four phase PSK demodulator
- 专利标题(中): 四相PSK解调器
-
申请号: US880836申请日: 1986-07-01
-
公开(公告)号: US4757272A公开(公告)日: 1988-07-12
- 发明人: Yukihiro Okada , Yuichi Ninomiya , Yoshimichi Ohtsuka , Yoshinori Izumi , Sei'ichi Goushi
- 申请人: Yukihiro Okada , Yuichi Ninomiya , Yoshimichi Ohtsuka , Yoshinori Izumi , Sei'ichi Goushi
- 申请人地址: JPX Osaka JPX Tokyo
- 专利权人: NEC Home Electronics Ltd.,Nippon Hoso Kyokai
- 当前专利权人: NEC Home Electronics Ltd.,Nippon Hoso Kyokai
- 当前专利权人地址: JPX Osaka JPX Tokyo
- 优先权: JPX60-149336 19850709
- 主分类号: H04L27/227
- IPC分类号: H04L27/227 ; H03D3/18 ; H03D3/24 ; H03K9/04 ; H04L7/04
摘要:
A demodulator for regenerating and demodulating a carrier signal from a four-phase PSK received signal having a data symbol preamble and a fixed phase (one of four phases) of a particular time width using a synchronous detection type demodulating system (remodulation type demodulating system). The demodulator includes an orthogonal demodulating circuit and a remodulating circuit for regenerating a carrier signal which is the data signal during a preamble transmission period from a received modulated signal. The remodulating circuit includes a demodulator having an AFC circuit for detecting a frequency change using a narrow band filter, means for suppressing frequency changes of the four-phase PSK modulated signal received and means for rendering constant the frequency of the regenerated carrier signal passing through the narrow band filter.