Patent ID: 9130628
Filing Date: 2015-09-08
Classification: H03F,H04B,H04L

Abstract:
1. A digital pre-distorter (DPD) for pre-distorting a plurality of input signals corresponding to a plurality of antennas, comprising: a DPD controller for storing (i) an antenna select value indicative of a count of selected antennas of the plurality of antennas, and (ii) a stream select value indicative of a selection of the plurality of input signals, and generating an antenna select signal based on the antenna select value, and stream select and stream routing signals based on the stream select value; a first address generator for receiving a first input signal of the plurality of input signals corresponding to a first antenna, and generating a first set of addresses; a second address generator for receiving a second input signal of the plurality of input signals corresponding to a second antenna, and generating a second set of addresses; a stream select multiplexer having (i) first and second input terminals connected to the first and second address generators for receiving the first and second sets of addresses, respectively, (ii) a select terminal connected to the DPD controller for receiving the stream select signal, and (iii) an output terminal for outputting an intermediate set of addresses; a first set of lookup tables corresponding to the first antenna for storing a plurality of coefficients, wherein the first set of lookup tables is connected to the first address generator for receiving the first set of addresses, and outputting a first set of coefficients of the plurality of coefficients; a second set of lookup tables corresponding to the second antenna for storing the plurality of coefficients, wherein the second set of lookup tables is connected to the output terminal of the stream select multiplexer for receiving the intermediate set of addresses, and outputting a second set of coefficients of the plurality of coefficients; a first dynamic routing logic unit connected to the first and second sets of lookup tables for receiving the first and second sets of coefficients, respectively, and to the DPD controller for receiving the stream routing signal, and outputting a selected set of coefficients; an antenna select multiplexer having (i) first and second input terminals for receiving the first and second input signals, respectively, (ii) a select terminal connected to the DPD controller for receiving the antenna select signal, and (iii) an output terminal for outputting a selected input signal; a plurality of multipliers, connected to the first dynamic routing logic unit and the antenna select multiplexer, for receiving the selected set of coefficients and the selected input signal, respectively, and generating a plurality of pre-distorted samples; an adder connected to the plurality of multipliers for receiving and adding the plurality of pre-distorted samples and generating a pre-distorted signal; an accumulator connected to the adder for receiving the pre-distorted signal and generating an accumulated pre-distorted signal; and a second dynamic routing logic unit, connected to the adder, the accumulator and the DPD controller, for receiving at least one of the pre-distorted and accumulated pre-distorted signals and the stream routing signal, and outputting at least one of first and second pre-distorted output signals corresponding to the first and second antennas, respectively.