Performance Analysis of OFDM System Using Adaptive FEC Code Control Technique for Mobile Wireless Communication

In this paper, we analyzes how a synchronization error affects receiving system when using a adaptive coded OFDM(Orthogonal Frequency Division Multi- plexing) transmission method in wireless LAN channel environment in which we can efficiently transmit wide- band information data. Since OFDM method uses Fast Fourier Transform(FFT) algorithm,, it can make the size of circuits smaller and also can vary transmission capacity by adaptive changing the number of subcarrier. Therefore, OFDM method may be applied as digital broadcasting and physical layer transm- ission mode of intelligent system. As a result, in OFDM system, we could see that the higher a frequency offset is, the worse performance will be, and we could see that there was performance improvement by applying adaptive coding technique in OFDM system in order to reach (BER=10-3). However, when we use 64-QAM (64Quadrature Amplitude Modulation), there was a huge influence between carriers by frequency offset at 0.05, 0.1.