Patent ID: 6188732
Filing Date: 2001-02-13
Classification: H03F,H04L

Abstract:
For use in a transmitter in a wireless network, a digital feedforward amplification system comprising:a first branch comprising:a digital combiner circuit capable of receiving a plurality of digital input signals and generating from at least one of said plurality of digital input signals at least one digital composite output signal;a DAC circuit for receiving said at least one digital composite output signal and converting said at least one digital composite output signal to at least one analog composite output signal;a modulation circuit capable of receiving a local RF signal and said at least one analog composite output signal and generating therefrom a modulated RF signal; anda power amplifier capable of amplifying said modulated RF carrier signal to produce an amplified RF output signal;a second branch comprising a distortion correction circuit capable of receiving said at least one digital composite output signal from said digital combiner circuit and generating a correction signal capable of at least partially canceling a distortion signal introduced into said amplified RF output signal by said power amplifier in said first branch; anda combiner circuit capable of combining said amplified RF output signal and said correction signal to thereby at least partially cancel said distortion signal.