Digital multi-band predistortion linearizer with non-linear subsampling algorithm in the feedback loop

A method for linearizing a transmitter, the method comprising:

• effecting predistortion, in parallel, of signal components;
• applied to a digital predistorter block in a transmit signal path, to output a plurality of distinct concurrent predistorted signals, each of the distinct concurrent predistorted signals being a function of the signal components;
• combining said plurality of distinct concurrent predistorted signals to form a multiband signal to be transmitted by a power amplifier block;
• subsampling, in a signal observation feedback path to generate a plurality of concurrent and distinct feedback signals;
• and
• using the concurrent and distinct feedback signals for synthesizing predistorter coefficients for the digital predistorter block.

A transmitter comprising:

• a concurrent digital multiband predistortion block configured to effect concurrent predistortion of respective band signals of a multiband signal to compensate for nonlinearities in the transmitter;
• a power amplifier block configured to amplify a predistorted multiband signal to provide an amplified multiband signal;
• and
• a signal observation feedback loop configured with a concurrent sampling block for concurrently sampling respective band signals corresponding to respective bands of the amplified multiband signal to produce concurrent feedback signals, the sampling being at a subsampling frequency lower than twice the highest signal frequency applied to the sampling block.

A method for linearizing a transmitter comprising:

• configuring a concurrent digital multiband predistortion block to effect concurrent predistortion of respective band signals of a multiband signal to compensate for nonlinearities in the transmitter;
• amplifying a predistorted multiband signal in a power amplifier block to provide an amplified multiband signal;
• and
• concurrently sampling, in a concurrent sampling block of a feedback loop, respective band signals corresponding to respective bands of the amplified multiband signal to produce concurrent feedback signals, the sampling being at a subsampling frequency lower than twice the highest signal frequency applied to the sampling block.