Methods of Enhancing Power Amplifier Linearity
First Claim
1. A method of transmitting an amplified RF signal comprising:
- providing a lookup table (LUT) for storing of predistortion data;
providing a power amplifier circuit for receiving a first analog RF signal and for providing the amplified RF signal therefrom;
receiving a digital modulated signal;
indexing the LUT to provide indexed predistortion data;
predistorting the digital modulated signal in dependence upon the indexed predistortion data to form a predistorted digital modulated signal;
converting the predistorted digital modulated signal into an analog modulated signal;
amplifying the analog modulated signal using the power amplifier to form the amplified RF signal;
sampling a portion of the amplified RF signal; and
,varying the index within the LUT for other than continuously changing the predistortion data that is used for predistorting of the digital modulated signal in dependence upon the sampled amplified RF signal.
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Abstract
A novel method of enhancing power amplifier linearity is disclosed. The invention is for use within a transceiver system and provides a method in the digital domain for predistorting a digital modulated signal to compensate for the non-linearity properties of the power amplifier and other components within the transmitter system. The RF output signal of the transmitter circuit is sampled and the corresponding amplitude and phase are detected using a receiver circuit. In dependence upon the amplitude and phase information, a look-up table is indexed to select the predistortion data and predistortion of the digital modulated signal occurs within the predistortion circuit.
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Citations
20 Claims
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1. A method of transmitting an amplified RF signal comprising:
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providing a lookup table (LUT) for storing of predistortion data; providing a power amplifier circuit for receiving a first analog RF signal and for providing the amplified RF signal therefrom; receiving a digital modulated signal; indexing the LUT to provide indexed predistortion data; predistorting the digital modulated signal in dependence upon the indexed predistortion data to form a predistorted digital modulated signal; converting the predistorted digital modulated signal into an analog modulated signal; amplifying the analog modulated signal using the power amplifier to form the amplified RF signal; sampling a portion of the amplified RF signal; and
,varying the index within the LUT for other than continuously changing the predistortion data that is used for predistorting of the digital modulated signal in dependence upon the sampled amplified RF signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification