Method and apparatus for capacity increase and enhanced communications performance in CATV networks
AssigneeTexas Instruments Incorporated
InventorsMordechai Segal, Ofir Shalvi, Zvi Reznic
Life of this patent
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Abstract
In a cable television (CATV) data communication network, channel throughput and communications robustness are increased in a manner that improves speed of data transmission while maintaining compatibility with existing specifications and equipment. Enhanced throughput can be realized using the return channel of the CATV network. Alternatively, data retransmission and/or diversity techniques can be used to improve throughput.
Claims10
A communication system for communicating a data signal using a cable television transmission medium, the communication arrangement comprising:
- an encoder configured to encode an input data stream as an encoder output signal;
- a transmission filter arrangement, responsive to the encoder output signal and configured to reduce adjacent channel interference in the encoder output signal and to generate a filter output signal;
- a modulator, configured to modulate the filter output signal, generating a modulated radio frequency signal for transmission using the cable television transmission medium;
- and
- a receiver arrangement coupled to receive the modulated radio frequency signal and configured to generate a stream of detected data based on the received modulated radio frequency signal, wherein the receiver arrangement comprises:
- an analog front end arrangement, configured to sample a desired signal from the received modulated radio frequency signal at less than the Nyquist rate and to cause thereby a shift in a center frequency of the desired signal from an initial frequency to a lower frequency;
- a modified matched filter configured to perform a convolution of a square-root raised cosine filter and a pre-calculated filter and to generate a modified matched filter output signal;
- an adaptive equalizer, responsive to the modified matched filter output signal and configured to generate an equalizer output signal;
- and
- a decoder, responsive to the equalizer output signal and configured to decode the equalizer output signal and to generate the stream of detected data.
A communication system for communicating a data signal using a cable television transmission medium, the communication arrangement comprising:
- an encoder configured to encode an input data stream as an encoder output signal;
- a transmission filter arrangement, responsive to the encoder output signal and configured to reduce adjacent channel interference in the encoder output signal and to generate a filter output signal;
- a modulator, configured to modulate the filter output signal, generating a modulated radio frequency signal for transmission using the cable television transmission medium;
- an analog front end arrangement, configured to sample a desired signal from the modulated radio frequency signal at less than the Nyquist rate and thereby to cause a shift in a center frequency of the desired signal from an initial frequency to a lower frequency;
- a modified matched filter configured to perform a convolution of a square-root raised cosine filter and a pre-calculated filter and to generate an modified matched filter output signal;
- an adaptive equalizer, responsive to the modified matched filter output signal and configured to generate an equalizer output signal;
- and
- a decoder, responsive to the equalizer output signal and configured to decode the equalizer output signal and to generate a stream of detected data.
A communication method for communicating a data signal using a cable television transmission medium, the communication method comprising:
- encoding an input data stream as an encoder output signal;
- filtering the encoder output signal to reduce adjacent channel interference in the encoder output signal, thereby generating a filter output signal;
- modulating the filter output signal to generate a modulated radio frequency signal for transmission using the cable television transmission medium;
- receiving the modulated radio frequency signal;
- generating a stream of detected data based on the received modulated radio frequency signal;
- sampling a desired signal from the received modulated radio frequency signal at less than the Nyquist rate and causing thereby a shift in a center frequency of the desired signal from an initial frequency to a lower frequency;
- performing a convolution of a square-root raised cosine filter and a pre-calculated filter and to generate an modified matched filter output signal;
- generating an equalizer output signal as a function of the modified matched filter output signal;
- and
- decoding the equalizer Output signal to generate the stream of detected data.
Dependencies are inferred from the claim text.