System for enhancing the performance of a CATV settop terminal
First Claim
1. A settop terminal for receiving a CATV signal comprising a plurality of channels over a transmission bandwidth, each channel for carrying information;
- the settop terminal comprising;
means for preprocessing said CATV signal to equalize each of said plurality of channels to a desired level, said preprocessing means comprising;
means for monitoring a channel at a lower frequency of said bandwidth and a channel at a higher frequency of said bandwidth;
means for determining the signal strength at said lower and higher frequencies;
means for calculating an attenuation profile from said determination; and
means for selectively attenuating the signal strength of a channel in response to said attenuation profile; and
channel selection means for selecting one of said equalized channels;
a selectable filter having;
a plurality of bandpass filters, each bandpass filter having a different passband encompassing at least two of said equalized channels; and
means for activating in response to said channel selection means one of said bandpass filters to filter said selected channel with a bandpass filter including the frequency of said selected channel; and
means for providing, from said selected channel, a baseband signal comprising said information for output to a display.
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Accused Products
Abstract
A system for use with a CATV settop terminal measures the input RF carrier signal power level at several frequencies within the CATV RF input bandwidth upon system power-up. The system utilizes these measurements to selectively equalize and process the RF input signal depending upon the carrier frequency selected and the desired signal level to be input to the RF tuner. The system refines the signal level by specifically measuring the signal level of the selected carrier frequency. The system further improves RF tuner performance by dynamically limiting the bandwidth input to the RF tuner depending upon the selected carrier frequency.
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Citations
6 Claims
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1. A settop terminal for receiving a CATV signal comprising a plurality of channels over a transmission bandwidth, each channel for carrying information;
- the settop terminal comprising;
means for preprocessing said CATV signal to equalize each of said plurality of channels to a desired level, said preprocessing means comprising; means for monitoring a channel at a lower frequency of said bandwidth and a channel at a higher frequency of said bandwidth; means for determining the signal strength at said lower and higher frequencies; means for calculating an attenuation profile from said determination; and means for selectively attenuating the signal strength of a channel in response to said attenuation profile; and channel selection means for selecting one of said equalized channels; a selectable filter having; a plurality of bandpass filters, each bandpass filter having a different passband encompassing at least two of said equalized channels; and means for activating in response to said channel selection means one of said bandpass filters to filter said selected channel with a bandpass filter including the frequency of said selected channel; and means for providing, from said selected channel, a baseband signal comprising said information for output to a display. - View Dependent Claims (2, 3, 4)
- the settop terminal comprising;
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5. A method for improving performance of a settop terminal for receiving a CATV signal comprising a plurality of channels over a transmission bandwidth, each channel carrying information, the method comprising:
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preprocessing said CATV signal to equalize each of said plurality of channels to a desired level, said preprocessing step comprising; monitoring a channel at a lower frequency of said bandwidth and a channel at a higher frequency of said bandwidth; determining the signal strength at said lower and higher frequencies; calculating an attenuation profile from said determination; and attenuating the signal strength of a channel in response to said attenuation profile; and selecting one of said equalized channels; selectively filtering using a plurality of bandpass filters, each filter having a different passband which includes at least two channels; activating one of said bandpass filters in response to said selecting step to filter said selected channel with a bandass filter having a frequency range which includes the frequency of said selected channel; and providing, from said selected channel, a baseband signal comprising said information for output to a display. - View Dependent Claims (6)
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Specification