Performance Improvement of IEEE 802. 11a Receivers Using DFT based Channel Estimator with LS Channel Estimator

In this paper the performance of one of the most widely deployed Wireless Local Area Networks (WLANs) based on IEEE 802. 11a standard has been analyzed using different modulation technique and convolution coding rates. The IEEE 802. 11a standard uses Orthogonal Frequency Division Multiplexing (OFDM) technique. In this analysis the channel estimation is pilot symbol based. A particular method proposed in literature, known as the Least Square Method (LS), along with its enhancement using Discrete Fourier transform (DFT) based estimator is investigated in this work. Three categories of channel profiles are considered for simulation, namely highly frequency selective, moderately frequency selective and frequency flat channels. The performances using these methods are compared by measuring raw bit-errorrate (BER) & mean square error (MSE), using 16 QAM modulation technique with different code rate in three different fading channel profile.