EP0243589A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Radio receiver with a carrier recovery control system
Assignee: Fujitsu Ltd
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Filing: 1987-02-03
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Granted: —
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Expires: 2007-02-03
Abstract
Abstract The present invention realizes, in a radio receiver which utilizes a sweep track type phase lock circuit, stable demodulation by effectively deciding start and stop of the sweep on the basis of the decoded code error.
Inventors
- 👤 Tokihiro Miyo
- 👤 Toshio Kawasaki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 06:10
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/32; H04L27/34; H04L27/38; H04L27/3818; H04L1/00; H04L1/004; H04L1/0045; H04L1/0054; H04L27/18; H04L27/22; H04L27/227; H04L27/2271; H04L27/2272
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
188 words
A radio receiver which receives a digital phase-modulated radio signal and outputs a digital signal by demodulating said received signal, comprising; demodulation means (10) for demodulating said receiving signal based on the recovered carrier and outputting a phase error information among the digital signal, said recovered carrier and said receiving signal; signal processing means (30), operatively connected to said demodulation means (10), for outputting error information of said demodulated digital signal; false-lock decision or detection means (40), operatively connected to said signal processing means ( 30 ), for detecting or deciding false-lock on the basis of said error information; sweep signal generating means (50), operatively connected to said false-lock decision or detecting means (40), for outputting a sweep signal when said false-lock detection or decision means (40) decides or detects the false lock, adding means (60) for adding the sweep signal sent from the sweep signal generating means (50) to the phase error information sent from said demodulation means (10), and carrier recovery means (20), operatively connected to said adding means (60), for outputting the signal having the frequency corresponding to said added signal as said recovered carrier.
Claim 2
Dependent Claim
188 words
A radio receiver which receives a digital phase-modulated radio signal and outputs a digital signal by demodulating said received signal, comprising; demodulation means (10) for demodulating said receiving signal based on the recovered carrier and outputting a phase error information among the digital signal, said recovered carrier and said receiving signal; signal processing means (30), operatively connected to said demodulation means (10), for outputting error information of said demodulated digital signal; false-lock decision or detection means (40), operatively connected to said signal processing means ( 30 ), for detecting or deciding false-lock on the basis of said error information; sweep signal generating means (50), operatively connected to said false-lock decision or detecting means (40), for outputting a sweep signal when said false-lock detection or decision means (40) decides or detects the false lock, adding means (60) for adding the sweep signal sent from the sweep signal generating means (50) to the phase error information sent from said demodulation means (10), and carrier recovery means (20), operatively connected to said adding means (60), for outputting the signal having the frequency corresponding to said added signal as said recovered carrier.
Claim 3
Dependent Claim
19 words
A radio receiver according to claim 1, wherein said signal processing means (30) is an error correction circuit (300).
Claim 4
Dependent Claim
32 words
A radio receiver according to claim 2, wherein said error correction circuit (300) corrects error of block coded signal and outputs error correction frequency information based on syndrome as said error information.
Claim 5
Dependent Claim
37 words
A radio receiver according to claim 2, wherein said error correction circuit (300) is a Viterbi decoder which corrects error of the signal as the convolutional code and outputs the normalized count information as said error information.
Claim 6
Dependent Claim
87 words
A radio receiver according to claim 1, wherein said signal processing means (30) comprises a phase change circuit which is controlled by the phase change signal generated by the error information which indicates whether the SOM (start of message) is decoded correctly or not and outputs said demodulated digital signal by changing it into the digital signal in such a case where it is received in the correct phase, and said false-lock decision or detecting means (40) decides false-lock on the basis of said phase change signal.
Claim 7
Dependent Claim
129 words
A radio receiver according to claim 1, wherein said signal processing means (30) comprises; a phase decision means (33) operatively connected to said demodulation means, for providing a Viterbi decoder (81) which is responsive to said demodulated digital signal and outputs a normalized signal and outputting a phase change signal by deciding a correct receiving phase from said normalized signal, and phase change circuit (31) operatively connected to said demodulation means and phase decision means, for outputting said demodulated digital signal after changing it to the digital signal in such a case where it is received with a correct phase by the phase change signal sent from said phase decision means (33), and said false-lock decision means (40) decides the false-lock on the basis of said phase change signal.
References Cited (Backward Citations)
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