Frequency offset synchronization for OFDM

Abstract

In communication system such as 2G, single carrier is used. But multi-path fading existed. So between two signals, there is a time guard interval. For this reason, the data rate is relatively low. To increase the data rate with the existing problem, multi-carriers also known as orthogonal frequency division multiplexing (OFDM) method was used. Although this method can increase data rate, it is sensitive to frequency offset. This frequency offset destroy the orthogonal frequency property. So it will generate inter-carrier-interference (ICI). That means it increases the probability error of the data. There are three methods to reduce the ICI. One of the methods was used is by adding a window function at the receiver part. By designing the window function, we can achieve a lower ICI to have a higher signal to ICI power ratio (SIR). In this project, a second order polynomial nyqusit window function was used and the maximum SIR was traced with each frequency offset value by this window function.