Adaptive predistortion for a transmit system
First Claim
1. A system for processing an input signal, the system comprising:
- an adaptive predistortion subsystem for receiving said input signal and for producing a predistorted signal by applying a deliberate predistortion to said input signal, wherein said deliberate predistortion includes magnitude distortions which adjust a magnitude of said input signal; and
a signal processing subsystem receiving and processing said predistorted signal and producing a system output signal, whereinsaid adaptive predistortion subsystem distorts said Input signal to compensate for distortions in said system output signal;
said signal processing subsystem decomposes said predistorted signal into separate components, each of said separate components being processed separately;
said processing subsystem combines said components after processing to produce said system output signal; and
said deliberate predistortion applied to said input signal by said adaptive predistortion subsystem to produce said predistorted signal is adjusted based on said system output signal.
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Accused Products
Abstract
Systems, methods, and devices relating to the provision of deliberate predistortion to an input signal to compensate for distortions introduced by an amplifier subsystem. An input signal is received by a predistortion subsystem which applies deliberate predistortions to the input signal to arrive at a predistorted signal. The predistorted signal is received by an amplifier subsystem which decomposes the signal, processes the decomposed signal, and then recombines the components to arrive at a system output signal. The predistortion subsystem adaptively adjusts the predistortions based on characteristics of the system output signal. A feedback signal, a replica of the system output signal, is used in updating lookup table entries used to determine the predistortion.
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Citations
40 Claims
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1. A system for processing an input signal, the system comprising:
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an adaptive predistortion subsystem for receiving said input signal and for producing a predistorted signal by applying a deliberate predistortion to said input signal, wherein said deliberate predistortion includes magnitude distortions which adjust a magnitude of said input signal; and
a signal processing subsystem receiving and processing said predistorted signal and producing a system output signal, wherein said adaptive predistortion subsystem distorts said Input signal to compensate for distortions in said system output signal;
said signal processing subsystem decomposes said predistorted signal into separate components, each of said separate components being processed separately;
said processing subsystem combines said components after processing to produce said system output signal; and
said deliberate predistortion applied to said input signal by said adaptive predistortion subsystem to produce said predistorted signal is adjusted based on said system output signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 16, 17, 18, 19, 20, 21, 29)
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10. A method of processing an input signal to produce a system output signal, the method comprising:
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a) receiving said input signal and accessing an entry in a lookup table;
b) applying a deliberate predistortion to said input signal to result in a predistorted signal, said deliberate predistortion being based on said entry;
c) decomposing said predistorted signal into at least two component signals;
d) combining said at least two component signals to produce said system output signal;
e) adjusting said deliberate predistortion based on said system output signal; and
f) updating at least one entry in said table. - View Dependent Claims (11, 12, 13, 14, 15, 22, 27, 28, 30, 36)
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23. An adaptive predistortion subsystem for use with a signal processing system which produces a system output signal, the predistortion subsystem comprising:
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determining means for determining a deliberate predistortion to be applied to an input signal, said determining means comprising a lookup table having entries, said entries being used to determine said deliberate predistortion and an interpolating means for determining values not found in said lookup table;
adjustment means for applying said deliberate predistortion to said input signal; and
update means for periodically updating said determining means based on characteristics of said system output signal. - View Dependent Claims (24, 25, 26, 31)
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32. A system for processing an input signal, the system comprising:
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an adaptive predistortion subsystem for receiving said input signal and for producing a predistorted signal by applying a deliberate predistortion to said input signal, wherein said deliberate predistortion includes phase distortions which adjust a phase of said input signal; and
a signal processing subsystem receiving and processing said predistorted signal and producing a system output signal, wherein said adaptive predistortion subsystem distorts said Input signal to compensate for distortions in said system output signal;
said signal processing subsystem decomposes said predistorted signal into separate components, each of said separate components being processed separately;
said processing subsystem combines said components after processing to produce said system output signal; and
said deliberate predistortion applied to said input signal by said adaptive predistortion subsystem to produce said predistorted signal is adjusted based on said system output signal. - View Dependent Claims (33, 34, 35, 37, 38, 39, 40)
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Specification