Abstract: (12462 Views)
Wide band code division multiple access (WCDMA) signals, transmitted by the
base station high power amplifiers (HPAs), show high peak to average power ratios
(PAPR), which results in nonlinear distortions. In this paper, using computer simulations
effect of using a predistorted HPA on the symbol error rate (SER) of multi-user detectors in
terms of output back-off (OBO) in the transmit power is analyzed. As well, using
polynomials for modeling predistorters to remove nonlinear distortions of traveling wave
tube amplifiers (TWTAs) and of solid state power amplifiers (SSPAs), effect of different
degrees of polynomials on the SER is investigated. Simulation results show that a
polynomial of degree 4 is a sufficient degree polynomial, which fits to the AM/AM
characteristic of the predistorter for TWTAs. As well, for solid state power amplifiers
(SSPAs) with different p values, different approximations are considered and sufficient
degree polynomials are found.
Type of Study:
Research Paper |
Subject:
Evolutionary Computation Received: 2010/09/15 | Revised: 2010/09/15 | Accepted: 2013/12/30