Method and apparatus for automatic frequency correction in a multimode device
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
H04J-003/06
H04M-001/00
H04B-001/7087
출원번호
US-0429878
(2009-04-24)
등록번호
US-8170000
(2012-05-01)
우선권정보
EP-06301112 (2006-11-02)
발명자
/ 주소
Chance, Gregory W.
Baills, Stephane L
Klomsdorf, Armin W
Kurby, Christopher N
출원인 / 주소
Motorola Mobility, Inc.
인용정보
피인용 횟수 :
0인용 특허 :
7
초록▼
A method and apparatus for synchronizing a system clock with a serving cell (102) associated with a first radio access technology and monitoring an adjacent cell (104) associated with a second radio access technology is provided. A communication device (100) includes a first synchronization device (
A method and apparatus for synchronizing a system clock with a serving cell (102) associated with a first radio access technology and monitoring an adjacent cell (104) associated with a second radio access technology is provided. A communication device (100) includes a first synchronization device (205) capable of synchronization with the serving cell (102) and a second synchronization device (206) capable of independently synchronizing with the adjacent cell (104). The first synchronization device (205) and second synchronization device (206) include independent frequency correction modules (207,208). Thus, the second frequency synchronization device (206) may be corrected per the adjacent cell (104) while the first synchronization device (205) remains synchronized with the serving cell (102). Thus, the same corrected system clock may be used between two radio access technologies.
대표청구항▼
1. A method for monitoring a heterogeneous radio access technology, the method comprising: providing in an electronic device a single system clock having a single frequency reference signal capable of synchronization with at least two radio access network technologies;synchronizing the single system
1. A method for monitoring a heterogeneous radio access technology, the method comprising: providing in an electronic device a single system clock having a single frequency reference signal capable of synchronization with at least two radio access network technologies;synchronizing the single system clock with a carrier signal of a first network employing a first radio access technology and applying a first frequency correction for the first radio access technology to the system clock;while the single system clock remains synchronized with the first network: monitoring a second network employing a second radio access technology by synchronizing a frequency synthesizer coupled to the single system clock with a carrier signal of the second network without altering synchronization of the system clock with the first network; andapplying, independent of the first frequency correction, a second frequency correction for the second radio access technology to the frequency synthesizer while leaving the single system clock unchanged. 2. The method of claim 1, further comprising providing a single main frequency synchronization loop coupled to the single system clock, wherein the step of synchronizing the single system clock with the first network comprises the step of frequency correcting the single system clock by the single main frequency synchronization loop in accordance with the first radio access technology. 3. The method of claim 2, wherein the single system clock comprises a fractional-N frequency synthesizer, wherein the step of frequency correcting the single system clock comprises the step of applying a frequency correction to the fractional-N frequency synthesizer. 4. A communication circuit capable of communication with at least a first radio access technology and a second radio access technology, the communication circuit comprising: a single system clock;a first synchronization device configured to synchronize the single system clock with a carrier signal;a second synchronization device, operable from the single system clock, and configured to synchronize the communication circuit with a carrier signal and apply a second frequency correction, independent of the first frequency correction, to the communication circuit while leaving the single system clock unchanged; anda first frequency correction module configured to and apply a first frequency correction to the single system clock; anda second frequency correction module, wherein upon the first synchronization device synchronizing the single system clock with a carrier signal associated with the first radio access technology and the second synchronization device synchronizing the communication circuit with a carrier signal of the second radio access technology, the frequency correction module corrects the second synchronization device independently from the first frequency correction module, thereby leaving the first synchronization device and single system clock unchanged. 5. The communication circuit of claim 4, wherein the first synchronization device comprises one of a fractional-N frequency synthesizer or a warped oscillator, the second synchronization device comprises a fractional-N frequency synthesizer. 6. The communication circuit of claim 5, wherein the frequency correction module is coupled to a control node of the fractional-N frequency synthesizer. 7. The communication circuit of claim 4, wherein the frequency correction module comprises a digital signal processing circuit configured to digitize a signal received from the second radio access technology as a digitized received signal and apply a frequency correction value to the digitized received signal. 8. A method in a mobile telephone for accessing more than one radio access technology with a single system clock, the method comprising: synchronizing the single system clock with a carrier signal received from a serving access node associated with a first radio access technology and applying a first frequency correction to the single system clock;synchronizing a frequency synthesizer with a carrier signal received from the serving access node; andwhile the single system clock remains synchronized with the carrier signal received from the serving access node, applying a second frequency correction, independent from the first frequency correction to the frequency synthesizer for a carrier signal received from the second access node associated with the second radio access technology while leaving the single system clock unchanged. 9. The method of claim 8, wherein applying the frequency correction comprises one of applying a frequency correction factor to a demodulated, digitized signal received from the second access node or applying a frequency correction adjustment value to the frequency synthesizer. 10. The method of claim 9, wherein synchronizing the single system clock with the carrier signal comprises one of applying a system clock correction factor to a fractional-N frequency synthesizer, altering a control voltage associated with a voltage controlled oscillator, or loading an oscillator.
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이 특허에 인용된 특허 (7)
Hyun-Kyu Lee KR, AFC device and method of controlling reception frequency in a dual-mode terminal.
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