Patent US5940744A successfully refreshed from Google Patents.
US5940744A
Expired / Lapsed
US
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Local frequency correction
Assignee: NEC Corp
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Filing: 1997-06-27
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Granted: 1999-08-17
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Expires: 2017-06-27
Abstract
Abstract A frequency correction of a local frequency is performed by first checking whether synchronization is acquired with respect to the received signal and, when the synchronization has been acquired, performing a frequency correction twice at different timing within a synchronization section, the frequency correction correcting the local frequency so as to reduce an error of the local frequency with respect to a received frequency of the received signal.
Inventors
- 👤 Yoshihide Uda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:55
CPC Classifications
H; H03; H03J; H03J7/00; H03J7/02; H03J7/04; H04; H04L; H04L7/00; H04L7/04; H04L7/10
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
89 words
A method for correcting a local frequency in a radio transceiver based on a received signal including a synchronization section and a data section, the method comprising the steps of: a) checking whether synchronization is acquired with respect to the received signal; and b) performing a frequency correction twice at different timing within a synchronization section when the synchronization has been acquired, the frequency correction correcting the local frequency so as to reduce an error of the local frequency with respect to a received frequency of the received signal.
Claim 2
Independent Claim
89 words
A method for correcting a local frequency in a radio transceiver based on a received signal including a synchronization section and a data section, the method comprising the steps of: a) checking whether synchronization is acquired with respect to the received signal; and b) performing a frequency correction twice at different timing within a synchronization section when the synchronization has been acquired, the frequency correction correcting the local frequency so as to reduce an error of the local frequency with respect to a received frequency of the received signal.
Claim 3
Dependent Claim
27 words
The method according to claim 1, further comprising the step of: c) performing the frequency correction at arbitrary timing when the synchronization has not been acquired yet.
Claim 4
Dependent Claim
48 words
The method according to claim 1, wherein the frequency correction comprises: detecting a frequency error of the local frequency with respect to the received frequency within the synchronization section; and correcting the local frequency based on the frequency error when the frequency error exceeds a predetermined permissible range.
Claim 5
Dependent Claim
27 words
The method according to claim 1, wherein the frequency correction is not performed in the data section of the received signal when the synchronization has been acquired.
Claim 6
Independent Claim
151 words
A method for correcting a local frequency in a radio transceiver based on a received signal including a synchronization section and a data section, the method comprising the steps of: a) checking whether synchronization is acquired with respect to the received signal; b) checking a first frequency error of the local frequency with respect to a received frequency of the received signal at a first predetermined time period within the synchronization section when the synchronization has been acquired; c) correcting the local frequency based on the first frequency error when the first frequency error exceeds a predetermined permissible range; d) checking a second frequency error of the local frequency with respect to the received frequency at a second predetermined time period within the synchronization section after the step c); and e) correcting the local frequency based on the second frequency error when the second frequency error exceeds the predetermined permissible range.
Claim 7
Independent Claim
151 words
A method for correcting a local frequency in a radio transceiver based on a received signal including a synchronization section and a data section, the method comprising the steps of: a) checking whether synchronization is acquired with respect to the received signal; b) checking a first frequency error of the local frequency with respect to a received frequency of the received signal at a first predetermined time period within the synchronization section when the synchronization has been acquired; c) correcting the local frequency based on the first frequency error when the first frequency error exceeds a predetermined permissible range; d) checking a second frequency error of the local frequency with respect to the received frequency at a second predetermined time period within the synchronization section after the step c); and e) correcting the local frequency based on the second frequency error when the second frequency error exceeds the predetermined permissible range.
Claim 8
Dependent Claim
57 words
The method according to claim 5, further comprising the step of: f) checking a frequency error of the local frequency with respect to the received frequency at arbitrary timing when the synchronization has not been acquired yet; and g) correcting the local frequency based on the frequency error when the frequency error exceeds the predetermined permissible range.
Claim 9
Dependent Claim
132 words
A communication control method for a radio communication apparatus having a local oscillator, a local frequency generated by the local oscillator being corrected based on a received signal including a synchronization section and a data section, the method comprising the steps of: a) checking whether synchronization is acquired with respect to the received signal; b) performing a frequency correction twice at different timing within a synchronization section when the synchronization has been acquired, the frequency correction correcting the local frequency so as to reduce an error of the local frequency with respect to a received frequency of the received signal to a predetermined permissible range; and c) producing received data from the data section of the received signal which is received using the local frequency corrected by performing the frequency correction twice.
Claim 10
Dependent Claim
132 words
A communication control method for a radio communication apparatus having a local oscillator, a local frequency generated by the local oscillator being corrected based on a received signal including a synchronization section and a data section, the method comprising the steps of: a) checking whether synchronization is acquired with respect to the received signal; b) performing a frequency correction twice at different timing within a synchronization section when the synchronization has been acquired, the frequency correction correcting the local frequency so as to reduce an error of the local frequency with respect to a received frequency of the received signal to a predetermined permissible range; and c) producing received data from the data section of the received signal which is received using the local frequency corrected by performing the frequency correction twice.
Claim 11
Dependent Claim
29 words
The communication control method according to claim 7, further comprising the step of: d) performing the frequency correction at arbitrary timing when the synchronization has not been acquired yet.
Claim 12
Dependent Claim
28 words
The communication control method according to claim 7, further comprising the step of: prohibiting transmission until the error of the local frequency falls into the predetermined permissible range.
Claim 13
Dependent Claim
27 words
The communication control method according to claim 8, further comprising the steps of: prohibiting transmission when the error of the local frequency exceeds the predetermined permissible range.
Claim 14
Dependent Claim
50 words
The communication control method according to claim 7, wherein the frequency correction comprises: detecting a frequency error of the local frequency with respect to the received frequency within the synchronization section; and correcting the local frequency based on the frequency error when the frequency error exceeds a predetermined permissible range.
Claim 15
Dependent Claim
29 words
The communication control method according to claim 7, wherein the frequency correction is not performed in the data section of the received signal when the synchronization has been acquired.
Claim 16
Dependent Claim
104 words
A frequency correction circuit for controlling a local oscillator provided in a radio communication apparatus based on a received signal including a synchronization section and a data section, comprising: a sync detector for detecting synchronization acquisition with respect to the received signal; an error detector for detecting an error of the local frequency with respect to a received frequency of the received signal; and a correction controller for correcting the local frequency twice at different timing within a synchronization section when the synchronization has been acquired such that the local frequency is corrected so as to reduce the error within a predetermined permissible range.
Claim 17
Dependent Claim
104 words
A frequency correction circuit for controlling a local oscillator provided in a radio communication apparatus based on a received signal including a synchronization section and a data section, comprising: a sync detector for detecting synchronization acquisition with respect to the received signal; an error detector for detecting an error of the local frequency with respect to a received frequency of the received signal; and a correction controller for correcting the local frequency twice at different timing within a synchronization section when the synchronization has been acquired such that the local frequency is corrected so as to reduce the error within a predetermined permissible range.
Claim 18
Dependent Claim
27 words
The frequency correction circuit according to claim 13, wherein the correction controller corrects the local frequency at arbitrary timing when the synchronization has not been acquired yet.
Claim 19
Dependent Claim
32 words
The frequency correction circuit according to claim 13, wherein the correction controller does not correct the local frequency in the data section of the received signal when the synchronization has been acquired.
Claim 20
Dependent Claim
142 words
A radio communication apparatus comprising: a local oscillator for generating a local frequency; a transceiver for transmitting a transmission signal and receiving a received signal based on the local frequency, the received signal including a synchronization section and a data section; a sync detector for detecting synchronization acquisition with respect to the received signal; an error detector for detecting an error of the local frequency with respect to a received frequency of the received signal; a correction controller for correcting the local frequency twice at different timing within a synchronization section when the synchronization has been acquired such that the local frequency is corrected so as to reduce the error within a predetermined permissible range; and a receiving controller for producing received data from the data section of the received signal which is received by the transceiver using a corrected local frequency.
Claim 21
Dependent Claim
142 words
A radio communication apparatus comprising: a local oscillator for generating a local frequency; a transceiver for transmitting a transmission signal and receiving a received signal based on the local frequency, the received signal including a synchronization section and a data section; a sync detector for detecting synchronization acquisition with respect to the received signal; an error detector for detecting an error of the local frequency with respect to a received frequency of the received signal; a correction controller for correcting the local frequency twice at different timing within a synchronization section when the synchronization has been acquired such that the local frequency is corrected so as to reduce the error within a predetermined permissible range; and a receiving controller for producing received data from the data section of the received signal which is received by the transceiver using a corrected local frequency.
Claim 22
Dependent Claim
27 words
The radio communication apparatus according to claim 16, wherein the correction controller corrects the local frequency at arbitrary timing when the synchronization has not been acquired yet.
Claim 23
Dependent Claim
32 words
The radio communication apparatus according to claim 16, wherein the correction controller prohibits the transceiver transmitting a transmission signal until the error of the local frequency falls into the predetermined permissible range.
Claim 24
Dependent Claim
31 words
The radio communication apparatus according to claim 17, wherein the correction controller prohibits the transceiver transmitting a transmission signal when the error of the local frequency exceeds the predetermined permissible range.
Claim 25
Dependent Claim
32 words
The radio communication apparatus according to claim 16, wherein the correction controller does not correct the local frequency in the data section of the received signal when the synchronization has been acquired.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-08-16 | 2003-02-15 | 2003-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-08-16 | 2007-02-15 | 2007-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-08-16 | 2011-02-15 | 2011-08-17 | $7700.00 | Window Closed / Lapsed |