Methods and apparatus for estimating and adjusting the frequency response of telecommunications channels
First Claim
1. A method for estimating a frequency response of a telecommunications channel, comprising:
- dividing a signal carried on the channel into a plurality of signal segments of limited duration;
identifying unvoiced signal segments; and
measuring spectral components of the unvoiced signal segments.
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Accused Products
Abstract
In methods and apparatus for estimating the frequency response of telecommunications channels, signals carried on the channels are divided into pluralities of signal segments of limited duration, unvoiced signal segments are identified, and spectral components of the unvoiced signal segments are measured. The measured spectral components may be integrated over time to derive time-averaged measurements of the spectral components. The time-averaged measurements may be compared to corresponding components of expected unvoiced signal spectra to improve the accuracy of the frequency response estimates. Filters may be inserted in the channels to adjust the frequency responses, the filters having filter characteristics selected in response to the measured spectral components. The methods and apparatus can be used to compensate for poor bass frequency response in voice channels.
21 Citations
22 Claims
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1. A method for estimating a frequency response of a telecommunications channel, comprising:
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dividing a signal carried on the channel into a plurality of signal segments of limited duration; identifying unvoiced signal segments; and measuring spectral components of the unvoiced signal segments. - View Dependent Claims (2, 3, 4, 5, 6, 20)
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7. Apparatus for estimating a frequency response of a telecommunications channel, comprising:
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a signal framer for dividing a signal carried on the channel into a plurality of signal segments of limited duration; an unvoiced signal detector for identifying unvoiced signal segments; and a spectrum analyzer for measuring spectral components of the unvoiced signal segments. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 22)
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15. A method for estimating a frequency response of a telecommunications channel, comprising:
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dividing a signal carried on the channel into a plurality of signal segments of limited duration; identifying signal segments containing only noise-like signals; and measuring spectral components of the identified signal segments. - View Dependent Claims (16, 17, 18, 19, 21)
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Specification