Power amplifier pre-distortion
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorLeonard Rexberg
Life of this patent
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Abstract
A power amplifier pre-distorter is formed by a FIR filter structure that includes an individual look-up table (LUT0, LUT1, LUT2) for each filter tap, where each look-up table represents a sampled polynomial in a variable representing signal amplitude. An absolute value block (10) selects, from each filter tap look-up table, a filter coefficient that depends on the amplitude of a corresponding complex signal value to be multiplied by the filter tap. This structure can pre-distort both for amplitude distortion and memory effects in the power amplifier.
Claims18
A power amplifier pre-distorter formed by a discrete-time filter structure with filter taps, characterized in that said filter structure includes
- an individual look-up table (LUT0, LUT1, LUT2;
- LUT01, LUT11, LUT21) for each filter tap, each look-up table representing a sampled polynomial in a variable representing signal amplitude;
- and
- means (10) for selecting, from each filter tap look-up table, a filter coefficient that depends on the amplitude of a corresponding complex signal value to be multiplied by the filter tap.
A base station including a power amplifier pre-distorter formed by a discrete-time filter structure with filter taps, characterized in that said filter structure includes
- an individual look-up table (LUT0, LUT1, LUT2;
- LUT01, LUT11, LUT21) for each filter tap, each look-up table representing a sampled polynomial in a variable representing signal amplitude;
- and
- means (10) for selecting, from each filter tap look-up table, a filter coefficient that depends on the amplitude of a corresponding complex signal value to be multiplied by the filter tap.
Dependencies are inferred from the claim text.