Bi-directional low pass filtering method and apparatus
AssigneeIntel Corporation
InventorsJames T. Doyle, Carl F. Liepold
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Abstract
The present invention provides a bi-directional low pass filtering method and apparatus for attenuating out-of-baseband components of data transmitted from an encoder to a decoder over a transmission medium. In one embodiment of the present invention, the bi-directional low pass filtering apparatus includes a Chebyshev filter that has a first phase response. This Chebyshev filter is coupled to a phase correction circuit, which has a second phase response. This second phase response of the phase correction circuit is designed to oppose the first phase response in order to offset variations in group delay in the data due to the Chebyshev filter.
Claims16
An encoder for transmitting data to a decoder over a transmission medium, the encoder comprising:
- a) a modulator for encoding a data bit stream supplied by a data source into a plurality of data symbol pulses;
- and
- b) a bi-directional low pass filter receiving said data symbol pulses, said low pass filter for filtering out out-of-baseband frequency components of said symbol pulses, said bi-directional low pass filter including:
- a Chebyshev filter having a first phase response,
- phase correction circuit coupled to said Chebyshev filter, said phase correction circuit having a second phase response, said second phase response opposing said first phase response in order to oppose variations in group delay of said data due to said Chebyshev filter.
An encoder for transmitting data to a decoder over a transmission medium, said encoder comprising:
- a) a modulator for encoding a data bit stream supplied by a data source into a plurality of data symbol pulses;
- and
- b) a bi-directional low pass filter receiving said data symbol pulses, said low pass filter for filtering out out-of-baseband frequency components of said symbol pulses, said bi-directional low pass filter including:
- a modified Chebyshev filter having a first phase response,
- phase correction circuit coupled to said modified Chebyshev filter, said phase correction circuit having a second phase response, said second phase response opposing said first phase response in order to oppose variations in group delay of said data due to said modified Chebyshev filter.
Dependencies are inferred from the claim text.