Estimation of carrier frequency offset and channel state information of generalize frequency division multiplexing systems by using a Zadoff–Chu sequence

Abstract

This study presents a computationally efficient algorithm for joint carrier frequency offset (CFO) and channel estimation for generalized frequency division multiplexing (GFDM) systems. The proposed algorithm employs a Zadoff–Chu (ZC) sequence as a training sequence spreading in the frequency domain for all subsymbols of the GFDM pilot symbol. The proposed algorithm first estimates the phase rotation factor in the pilot symbol and then coherently combines all subsymbols according to this estimate. The CFO is then estimated from the root of the cost function constructed using the ZC sequence. Finally, the channel estimate is obtained through maximum likelihood estimation and the use of CFO-compensated signals. Compared with conventional approaches, in addition to demonstrating improved estimation accuracy, the proposed algorithm is more computationally efficient because of the use of the ZC sequence. Computer simulations confirm the feasibility of the proposed algorithm.