Complex Gain Predistortion in WCDMA Power Amplifiers with Memory Effects

: Power amplifiers are essential components in communication systems and are inherently nonlinear. The nonlinearity creates spectral growth beyond the signal bandwidth, which interferes with adjacent channels. It also causes distortions within the signal bandwidth, which decreases the bit error rate at the receiver. In digital predistortion system, an inverse characteristic of power amplifier is generated and its amplitude and phase are combined to the signal input. So the input signal is predistorted and the power amplifier response is corrected. This process has to be controlled at high accuracy to achieve a satisfactory compensation effect. The inverse characteristics are stored in a memory (look-up table) and this data are updated using an error that is produced by comparing the outputs of power amplifier with the input signals. In this paper a novel technique for compensating such effects is proposed. It is a combination of two techniques, memory polynomial predistortion and the g...

• Type: Journal
• Year: 2010
• Where: IAJIT
• Authors: Pooria Varahram, Somayeh Mohammady, Mohd Hamidon, Roslina Mohd Sidek, Sabira Khatun
• Keywords: IAJIT 2010, Inverse Characteristics, Power Amplifier, Signal Bandwidth