A simplified scattered pilot for FBMC/OQAM in highly frequency selective channels

Filterbank multi-carrier with offset quadrature amplitude modulation (FBMC/OQAM) avoids the usage of the cyclic prefix (CP) by using more localized prototype filters. However, channel estimation in highly frequency selective channels is very challenging, especially for the scattered pilots due to the intrinsic interference leaked from the neighboring symbols. This paper presents a novel pilot design called Composite Pilot Pair (CPP), which exploits the localization property of the filters to enable a simple estimation procedure at the receiver. The proposed CPP design and corresponding receiving algorithm have been evaluated on an FBMC-based, Long Term Evolution (LTE) like mobile system. The evaluation shows that the proposed algorithm outperforms the conventional auxiliary pilot algorithms substantially, both in terms of power overhead and pilot mean square error (MSE), whereas the overall receive complexity is low. Moreover, the proposed method respects the frame design principles for the mobile downlink, and is applicable to both common and dedicated pilot symbols in the next generation mobile systems.