US 12,368,415 B2
Dual-band digital pre-distortion system and method
Tian He, Plano, TX (US); Chad Young, Carrollton, TX (US); Shavantha Kularatna, Flower Mound, TX (US); Peter Novak, Keller, TX (US); and Jacob Edward Longwell, Northlake, TX (US)
Assigned to Nokia Solutions and Networks Oy, Espoo (FI)
Filed by Nokia Solutions and Networks Oy, Espoo (FI)
Filed on Nov. 17, 2021, as Appl. No. 17/455,278.
Claims priority of application No. 20206233 (FI), filed on Dec. 1, 2020.
Prior Publication US 2022/0173704 A1, Jun. 2, 2022
Int. Cl. H04L 25/49 (2006.01); H03F 1/32 (2006.01); H03F 3/21 (2006.01)
CPC H03F 1/3258 (2013.01) [H03F 3/21 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method comprising:
receiving an input signal comprising a first subband signal associated with a first centre frequency, ω1, and a second subband signal associated with a second centre frequency, ω2;
applying a pre-distortion to the input signal to generate a pre-distorted signal, the pre-distortion applying an inverse to a power amplification model associated with a power amplifier; and
outputting the pre-distorted signal for power amplification,
and wherein the power amplification model or the inverse to the power amplification model comprises:
a first plurality of terms, each of the first plurality of terms comprising a product of a complex coefficient, a first power factor, and the first sub band signal or the second subband signal, wherein each of the first plurality of terms is associated with a frequency centre of the first centre frequency, ω1, or the second centre frequency, ω2; and
a second plurality of terms, each of the second plurality of terms comprising a product of a complex coefficient, a second power factor and a complex factor comprising a product of the first subband signal raised to a first power and a conjugate of the second subband signal raised to a second power or a product of the second subband signal raised to a first power and a conjugate of the first subband signal raised to a second power, wherein each of the second plurality of terms is associated with a frequency centre of a difference between an integer multiple of the first centre frequency and an integer multiple of the second centre frequency.