Effects of Channel Estimation Error and Nonlinear HPA on the Performance of OFDM in Rayleigh Channels with Application to 802.11n WLAN

In this paper, we present the performance analysis of an orthogonal frequency division multiplexing (OFDM) system which is subject to nonlinear distortion and channel estimation error in a Rayleigh fading channel. The nonlinear distortion is produced by a high power amplifier (HPA) located at the transmitter. The traditional approach for obtaining the bit error rate (BER) of such OFDM systems is often a difficult task due to the integration over the joint probability density function (PDF) of the channel impulse response and its estimate. The channel estimation error model presented in this paper facilitates the derivation of a closed form BER expression that is otherwise difficult to obtain by taking the traditional approach. For the purpose of simulation, the model under study is extended to a Wireless Local Area Network (WLAN) system which is implemented based on the IEEE 802.11n standard. Finally, the simulation results obtained from the extended model for various sets of parameters are compared with the theoretical results.