Semiblind Single-Carrier MIMO Channel Estimation Using Overlay Pilots

Semiblind (SB) channel estimation based on the expectation-maximization (EM) algorithm is studied for the case of single-carrier multiple-input-multiple-output (MIMO) systems using overlay pilots. Iterative channel estimation and data detection are performed at the receiver. We provide the formulation of the channel estimator and present numerical results on the iterative receiver performance. Presented results show an interesting performance improvement and a fast convergence using the SB scheme when enough transmit power is attributed to pilots. The proposed scheme is also compared to the classical case of time-multiplexed pilots, and the tradeoff between the channel-estimation quality and the data-transmission rate is discussed.