Adjustment of period of real-time slow drift correction of alignment of handset's local oscillator for a cordless telephone
First Claim
1. A method of determining a period for an operation between a remote unit handset and a matching base unit, said method comprising:
- detecting a re-charging to a of said remote handset from a by said matching base unit; and
in response to detecting the re-charging of said remote handset, adjusting a period between a check of frequency alignment between said remote handset and said matching base unit based on a battery voltage level in said remote handset.
5 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus to perform a real-time drift correction of a remote handset'"'"'s local oscillator in a digital cordless telephone. The remote handset begins in a standby (sniff) mode. The remote handset periodically wakes from a sleep mode and goes into a normal link verification mode. Once in the link verification mode, the remote handset enters a time division duplexing (TDD) mode and attempts to establish a link with a base unit based on the timing of the TDD data frame. After the remote handset establishes a link with the base unit, the remote handset requests a security word from the base unit. Upon receiving the requested security word, the remote handset determines if the requested security word matches a security word of the remote handset. The remote handset implements a software frequency adjustment of its local oscillator. Once per frame, the remote handset enters a timing recovery state where the current state of the frame is compared with a previous state. When the cumulative timing slip is greater than a designated threshold, a frequency adjustment is made. During this exchange of commands between the remote handset and base unit, the remote handset continuously adjusts its local oscillator to achieve frequency alignment within, e.g., 1 part per million (ppm). Alternatively, frequency alignment may be achieved to a specified value. The period of the frequency alignment can be lengthened (or even suspended) during certain power critical modes to reduce power consumption. For example, the period of the link verify operations (and thus the frequency alignment) can be lengthened or suspended when the remote handset is being quick charged. Moreover, the period of the link verify operations can be adjusted based on a voltage level of the battery in the remote handset.
40 Citations
35 Claims
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1. A method of determining a period for an operation between a remote unit handset and a matching base unit, said method comprising:
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detecting a re-charging to a of said remote handset from a by said matching base unit; and in response to detecting the re-charging of said remote handset, adjusting a period between a check of frequency alignment between said remote handset and said matching base unit based on a battery voltage level in said remote handset. - View Dependent Claims (2, 3, 4)
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5. Apparatus for determining a period for an operation between a remote unit handset and a matching base unit, comprising:
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means for detecting a re-charging to a of said remote handset from a by said matching base unit; and means, responsive to said means for detecting a re-charging of said handset detecting the re-charging of said handset, for adjusting a period between a check of frequency alignment between said remote handset and said matching base unit based on a battery voltage level in said remote handset. - View Dependent Claims (6, 7, 8)
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9. A method of adjusting a frequency of an alignment operation between two wireless components that communicate with one another, comprising:
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detecting a re-charging of one of said two wireless components; monitoring a voltage output level of a battery in at least said one of said two wireless components; and decreasing a frequency of said alignment operation between said two wireless components if in response to detecting the re-charging of said one of said two wireless components and determining by said monitoring that the monitored voltage output level of said battery falls is below a given threshold level. - View Dependent Claims (10, 11, 12)
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13. Apparatus for adjusting a frequency of an alignment operation between two wireless components that communicate with one another, comprising:
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means for detecting a re-charging of one of said two wireless components; means for monitoring a voltage output level of a battery in at least said one of said two wireless components; and means for decreasing a frequency of said alignment operation between said two wireless components if in response to said means for detecting the re-charging of said one of said two wireless components, and said means for monitoring determining that the monitored voltage output level of said battery falls is below a given threshold level. - View Dependent Claims (14, 15, 16)
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17. A method for adjusting a frequency of alignment operations of a wireless device, comprising:
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detecting a re-charging of the wireless device; and in response to detecting the re-charging of the wireless device, adjusting the frequency of alignment operations of the wireless device. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A wireless device, comprising:
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a local oscillator configured to generate clock signals for use in the wireless device; and a processor configured to detect a re-charging of the wireless device by an external matching base unit and, in response to detecting the re-charging of the wireless device, to adjust a frequency of alignment operations of the local oscillator in the wireless device. - View Dependent Claims (28, 29, 30)
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31. A method for adjusting a frequency of a local oscillator in a wireless device, comprising:
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detecting a re-charging of the wireless device by an external unit; periodically transitioning the re-charging wireless device from a standby mode to an authentication mode; exchanging commands between the wireless device and the external unit during the authentication mode; adjusting the frequency of the local oscillator to within a predetermined value of a frequency of an oscillator of the external unit based on timing information derived from the exchanged commands; and transitioning the wireless device back from the authentication mode to the standby mode. - View Dependent Claims (32, 33, 34, 35)
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Specification