发明名称 |
Four phase PSK demodulator |
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.
|
申请公布号 |
US4757272(A) |
申请公布日期 |
1988.07.12 |
申请号 |
US19860880836 |
申请日期 |
1986.07.01 |
申请人 |
NEC HOME ELECTRONICS LTD.;NIPPON HOSO KYOKAI |
发明人 |
OKADA, YUKIHIRO;NINOMIYA, YUICHI;OHTSUKA, YOSHIMICHI;IZUMI, YOSHINORI;GOUSHI, SEI'ICHI |
分类号 |
H04L27/227;(IPC1-7):H03D3/18;H03D3/24;H03K9/04;H04L7/04 |
主分类号 |
H04L27/227 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|