Channel estimation performance of OQAM/FBMC and QAM/FBMC systems

This paper discusses the preamble-based channel estimation for OQAM/FBMC and QAM/FBMC systems. Firstly, conventional channel estimation methods for OQAM/FBMC system, namely pair of pilot (POP) and interference approximation (IAM), are reviewed. Since the OQAM/FBMC system achieves orthogonality only in the real domain, the OQAM/FBMC system suffers from the intrinsic interference under the complex channel assumption, which makes the channel estimation problem still challenging for OQAM/FBMC system. To achieve orthogonality in the complex domain, we propose a new QAM/FBMC system equipped with a pair of prototype filters. Based on the configuration of the filters, the preamble and associated channel estimator are also devised for the proposed QAM/FBMC systems. Simulation results show that the proposed QAM/FBMC system not only enables low-PAPR preamble transmission, but also achieves superior channel estimation performance over diverse channel conditions.