An improved ESPRIT-based blind CFO estimation for OFDM in the presence of I/Q imbalance

The estimation of carrier frequency offset (CFO) is an important issue in the study of OFDM systems. In the past, many CFO estimation methods have been proposed. In particular, the ESPRIT-based blind CFO estimation method is attractive because of its bandwidth efficiency. It can yield accurate estimates and it works for non constant modulus modulation symbols. This paper improves the ESPRIT-based method in two ways. Firstly, we show how the information of virtual carrier location can be exploited to further enhance the estimation accuracy. Secondly, we also derive a new algorithm that can estimate CFO in the presence of I/Q imbalance.