Analysis of Effect of Carrier Frequency Offset on Performance of LTE Uplink

Carrier frequency offset CFO is one of major issues effecting performance of Orthogonal Frequency Division Multiplexing OFDM based systems. It is basically caused due to oscillator instability and Doppler shift introduced in the channel. It seriously degrades the system performance. This problem becomes even worse in uplink case because of random nature of users, since each user experiences different offset. Single Carrier FDMA is also an OFDM based system which is actually DFT based OFDM. Long Term Evolution LTE uses SC-FDMA instead of OFDM in uplink due to problem of Peak to Average Power Ratio (PAPR) as mobile handsets have limited battery power. In this research work, we focus on analyzing effect of CFO on the performance of LTE uplink system. The simulation results in terms of constellation diagrams and Bit Error Rate graphs show that system performance is seriously degraded due to carrier offset and suppression techniques have to be employed in order to save the integrity of user data.