A postdistortion receiver for mobile communications
L. Quach, Shawn P. Stapleton · 2002
A postdistortion receiver for possible future mobile communication systems that can increase both the spectral efficiency and the transmitter's power efficiency is presented. Postdistortion is a technique, implemented at the base-station receiver, to compensate for AM-AM and AM-PM nonlinearities of a mobile transmitter's amplifier, which, if uncompensated, would cause adjacent channel interference. A new adaptation method is demonstrated to compensate for slow variations in power amplifier characteristics without an interruption for a training period. The simulation and measured results show that the postdistortion technique can improve the out-of-band emission by up to 20 dB; the corresponding increase in mobile transmitter power efficiency is approximately a factor of 10. The spectral efficiency is increased by 20% with the postdistortion implementation.