Now these days OFDM is windy used for data communication. OFDM is used for transferring the high data rate. But there are some disadvantages of OFDM one of them is Carrier frequency offset. The cause behind the CFO is the synchronization between frequencies. It is a very sensitive so that hard to manage these frequencies. This paper presents a hybrid technique for carrier frequency offset (CFO) estimation in orthogonal frequency division multiplexing (OFDM) over frequency selective fading channel by using pilot tone and Gaussian particle filtering (PF) approach. An analytic expression in form of mean square error (MSE) of frequency offset synchronization is reported, and simulation results verify theoretical analysis and show approximate 97% improvement.