Simulation of third order intermodulation distortion on the constellation error in RF transmitter of WLAN OFDM System

Abstract

In wireless digital communication, an advance non-linear distortion simulation is required in order to analyze the performance of a Radio Frequency (RF) system. This technical paper therefore, reports a simulation of third order intermodulation (IM3) distortion on the constellation error (a key measure of modulation quality) in RF transmitter of wireless local area network (WLAN) orthogonal frequency division multiplexer (OFDM) system. The selected of RF transmitter architecture is based on the off-theshelf components. Advanced Design System (ADS) software has been used for RF transmitter modeling and simulation. Constellation error simulation is based on the IEEE 802.11a standard. As results, two observations have been obtained. First, it is shown that the IM3 distortion in the RF transmitter for WLAN OFDM system must be kept in minimum level in order to get lower constellation error. Second, at higher data rate (e.g. 54 Mbps), the constellation error is very sensitive to the IM3 distortion compared to lower data rate (e.g. 6 Mbps) with the same IM3 distortion level.