The high power amplifier (HPA) is a key part of the transmit chain, but inherently nonlinear. Nonlinearity of the HPA causes intermodulation distortion (IMD). In order to compensate for the IMD, linearization techniques are required. Digital predistortion is one such technique. In this paper, we present an overview of the digital predistortion linearizer that we developed and the experimental results of applying this linearizer to an HPA for IS-95. The experimental results show that the developed linearizer effectively suppresses the IMD by 7 to 10 dB depending on the signal bandwidth.
['Sungbin Im', 'Edward J. Powers']
An application of a digital predistortion linearizer to CDMA HPAs