Analysis of Joint Estimation of CFO, I/Q Imbalance& Channel Response for OFDM MIMO Systems

Abstract: In this project we are going to analyse the joint estimation of inphase and quadrature-phase (I/Q) imbalance and carrier frequency offset (CFO). The channel response for multiple-input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems is done using training sequences. The CFO,I/Q imbalance are caused due to mismatch of carrier frequency at the transmitter and local oscillator frequency at the receiver. This paper presents a novel approach for joint estimation of I/Q imbalance, CFO and channel estimation for Multiple Input Multiple Output (MIMO) OFDM systems. A new energy is introduced called channel residual energy (CRE). The proposed method uses OFDM block for training. In this paper, we show that by minimizing the CRE, we can jointly estimate the I/Q imbalance and CFO without knowing the channel response. The results show that the mean-squared error (MSE) of the proposed method is close to the Cramer-Rao bound (CRB).

Keywords: MIMO, OFDM, Carrier Frequency Offset.