Abstract: An example apparatus includes: memory having a terminal, the memory to store machine-readable instructions and adjacent channel leakage data; and programmable circuitry having a terminal coupled to the terminal of the memory, the programmable circuitry to execute the machine-readable instructions to: determine a range of out-of-band frequencies responsive to adjacent channel leakage ratio data; generate weight values responsive to electromagnetic emissions within the range of out-of-band frequencies of a first signal; modify a pre-distortion function responsive to the weight values; and apply the modified pre-distortion function to generate a second signal, the second signal to exhibit fewer emissions in the range of out-of-band frequencies than the first signal during transmission.

Abstract: An example apparatus includes: programmable circuitry to receive an input signal, a digital pre-distorter (DPD) output signal, and a power amplifier (PA) feedback signal; populate a partial matrix with a threshold number of rows of equation terms; compute a respective observation terms for each row in the threshold number of rows; reduce the partial matrix into a Hermitian matrix and reduce the observation terms into a vector; accumulate the Hermitian matrix and the vector onto the memory; regularize, after a determination that a threshold number of Hermitian matrices have been accumulated, the memory to form an output matrix; and pre-distort the input signal using the output matrix.