System and method for transmit signal spectral shaping
AssigneeParadyne Corporation
InventorsGordon Bremer, William L. Betts
Life of this patent
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Abstract
A system and method for shaping a transmit signal spectrum allows a transmit precoder and a spectral shaping filter to precode and shape a transmit signal without the need for receiving communication channel response information from a receiver or the need for a training period. The resultant shaped transmit spectrum signal meets regulatory requirements for the amount of energy transmitted per hertz of bandwidth.
Claims21
A system for shaping a transmit signal spectrum, comprising:
- a filter having a set of filter coefficients defining a particular transmit spectrum, said filter designed to receive as input a signal space mapped flat spectrum signal, said filter designed to process said signal space mapped flat spectrum signal and output a precoded signal having a desired precoded signal spectrum;
- a feedback loop containing a modulo operation designed to operate on said precoded signal from said filter, said modulo operation designed to restrict the magnitude of said precoded signal resulting in a substantially flat spectrum signal;
- a subtractor designed to subtract the output signal of said modulo operation from a signal space mapped signal resulting in said signal space mapped flat spectrum signal;
- and
- an adder designed to add the output of said filter to said signal space mapped flat spectrum signal, said adder designed to output a precoded transmit signal that meets a desired signal spectrum;
- wherein, the precoded transmit signal is the output of the system for shaping the transmit signal spectrum.
A method for shaping a transmit signal spectrum in a communication device, comprising the steps of:
- supplying to a filter having a set of filter coefficients defining a particular transmit spectrum, a signal space mapped flat spectrum signal, said filter designed to process said signal space mapped flat spectrum signal and output a precoded signal having a particular precoded signal spectrum;
- supplying said precoded to a modulo operation in a feedback loop, said modulo operation designed to restrict the magnitude of said precoded signal resulting in a flat spectrum signal;
- supplying said flat spectrum signal to a subtractor resulting in said signal space mapped flat spectrum signal;
- and
- adding said precoded signal to said signal space mapped flat spectrum signal resulting in a precoded transmit signal that meets a desired signal spectrum;
- wherein, the precoded transmit signal is the output of the communication device.
A computer readable medium having a program for shaping a transmit signal spectrum in a communication device, comprising:
- means for supplying to a filter having a set of filter coefficients defining a particular transmit spectrum, a signal space mapped flat spectrum signal, said filter designed to process said signal space mapped flat spectrum signal and output a precoded signal having a particular precoded signal spectrum;
- means for supplying said precoded to a modulo operation in a feedback loop, said modulo operation designed to restrict the magnitude of said precoded signal resulting in a flat spectrum signal;
- means for supplying said flat spectrum signal to a subtractor resulting in said signal space mapped flat spectrum signal;
- and
- means for adding said precoded signal to said signal space mapped flat spectrum signal resulting in a precoded transmit signal that meets a desired signal spectrum;
- wherein, the precoded transmit signal is the output of the communication device.
Dependencies are inferred from the claim text.