Title:
CHANNEL ESTIMATION AND SYNCHRONIZATION FOR OFDM SYSTEM

Authors:
Said Elkassimi, Said Safi

Abstract:
The OFDM system carries the message data on orthogonal subcarriers for parallel transmission, combating the distortion caused by the frequency selective channel or equivalently, the intersymbol- interference in the multi-path fading channel. However, the advantage of the OFDM can be useful only when the orthogonality is maintained, thus In an OFDM system, the transmitter modulates the message bit sequence into PSK/QAM symbols, performs IFFT on the symbols to convert them into time domain signals, and sends them out through a (wireless) channel The received signal is usually distorted by the channel characteristics. In order to recover the transmitted bits, the channel effect must be estimated and compensated in the receiver. First we will discuss synchronization techniques to manage the STO and CFO potential problems in OFDM systems, and the use of DFT technique for estimating the mobile radio channel response. Finally, we simulate the synchronization technique STO, and LS-linear, LS-spline and MMSE with DFT method for estimating the mobile radio channel parameters Bran A, thus a comparison of performance of LS-linear, LS-spline and MMSE with DFT method.