Enhanced return path performance using modulation-based alignment criteria
First Claim
1. A method of allocating signal power among a plurality of different channels on the return path of a cable data network, each of said channels employing one of a plurality of different signal formats, the method comprising the steps of:
- a) obtaining parameters specifying modulation type and symbol rate for each signal format employed on the return path, wherein said parameters thereby provide a parameter of channel bandwidth;
b) obtaining the AWGN noise floor across the reverse link;
c) choosing a nominal maximum available RF power for transmitting signals on the reverse path;
d) obtaining a predetermined BER expression for each of the modulation types employed on the return path, each of said predetermined BER expressions requiring a plurality of input values that includes said at least one parameter obtained in step a) for the signal format associated therewith, the AWGN noise floor across the reverse link obtained in step b), and a maximum available RF power for transmitting signals on the return path obtained in step c);
e) formulating an expression for an average BER based on the predetermined BER expressions obtained in step d) and on a number of channels of each signal format type associated with a corresponding BER expression obtained in said obtaining step d);
e) calculating the power to be allocated to each signal format by minimizing said average BER; and
f) allocating power to each of the plurality of channels associated with each signal format in accordance with the power calculated in step e).
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Accused Products
Abstract
A method of allocating power among a plurality of signals, at least two of the signals employing different signal formats, located on different channels of the return path of a cable data network, divides a total power available for the signals on the return path in accordance with a minimum value of an average BER for all the signals and allocates power to each of the signals in accordance therewith. Specifically, a number of parameters are obtained including modulation type and symbol rate for each signal format employed on the return path, the AWGN noise floor across the reverse link, the nominal maximum available RF power for transmitting signals on the reverse path. A predetermined BER expression for each of the modulation types employed on the return path is then obtained, each of the expressions requiring a plurality of input values that includes the above-noted parameters. An expression is then formulated for an average BER based on the predetermined BER expressions and on a number of channels of each signal format type associated with a corresponding BER expression. The power to be allocated to each signal format by minimizing the average BER is then calculated.
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Citations
20 Claims
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1. A method of allocating signal power among a plurality of different channels on the return path of a cable data network, each of said channels employing one of a plurality of different signal formats, the method comprising the steps of:
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a) obtaining parameters specifying modulation type and symbol rate for each signal format employed on the return path, wherein said parameters thereby provide a parameter of channel bandwidth; b) obtaining the AWGN noise floor across the reverse link; c) choosing a nominal maximum available RF power for transmitting signals on the reverse path; d) obtaining a predetermined BER expression for each of the modulation types employed on the return path, each of said predetermined BER expressions requiring a plurality of input values that includes said at least one parameter obtained in step a) for the signal format associated therewith, the AWGN noise floor across the reverse link obtained in step b), and a maximum available RF power for transmitting signals on the return path obtained in step c); e) formulating an expression for an average BER based on the predetermined BER expressions obtained in step d) and on a number of channels of each signal format type associated with a corresponding BER expression obtained in said obtaining step d); e) calculating the power to be allocated to each signal format by minimizing said average BER; and f) allocating power to each of the plurality of channels associated with each signal format in accordance with the power calculated in step e). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method of allocating power among a plurality of signals transmitted on different channels of the return path of a cable data network, said method comprising the steps of:
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a) dividing a total power available for the signals on the return path in accordance with a minimum value of an average BER for all the signals; and b) allocating power to each of the signals in accordance with step (a), wherein at least two of said signals employ different signal formats.
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Specification