System and method for estimation and correction of carrier frequency offset in MIMO-OFDM based wireless communications systems

摘要

This invention relates to a Multi-Input Multi-Output Orthogonal Frequency Divisional Multiplexing (MIMO-OFDM) is a transmission technology for many current and next generation wireless communication systems. Carrier Frequency Offset (CFO) Estimation and Correction is one of the most important requirement of the proper reception of MIMO-OFDM Signals. The invention provides a null subcarrier based scheme to accomplish this task. The CFO is estimated by employing the covariance matrix of the signals on all receiving antennas with a cost function which minimizes the energy falling on the null subcarrier locations due to frequency offset. The proposed approach results in very low computational complexity as it uses a two step procedure, making it very attractive for real time applications. Also a new null subcarrier allocation scheme based on Fibonacci series is proposed which ensures a frequency offset estimation range equal to the maximum possible range equal to the OFDM bandwidth.