Combined technique of MMSE Estimator and Kalman Filter to suppress CFO Effect in LTE Uplink Transmission

The third generation partnership project (3GPP) Long Term Evolution (LTE) is the newest technology to deal with the increasing need of mobile broadband services. Single-Carrier Frequency-Division Multiple Access (SC-FDMA) technology is being used for uplink (UL) transmission. But SC-FDMA system is also susceptible to CFO, comparable with other Orthogonal Frequency Division Multiple (OFDM) based systems which is generally occurs due to Doppler shift and oscillator mismatch. The numerous CFOs of the received signals will disrupt the orthogonality between the various subcarriers. Consequently, the generation of ICI and MAI into the received signals will occur. Thus the performance of the system will be sincerely degraded. To suppress the effect of CFO, the new hybrid technique of MMSE Estimator and Kalman Filter is proposed. Simulations results show that the algorithm is effective in the presence of CFO. The value of BER diminishes to some extent by applying proposed technique and results in significant improvement in the system performance. Index Terms – CFO, LTE Uplink, Kalman Filter, MMSE.