Preamble-based channel estimation methods with high spectral efficiency for pulse shaping OFDM/OQAM systems

The classical preamble-based channel estimation for pulse shaping orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) systems requires zero-value guard symbols to guarantee interference avoidance, which leads to low spectral efficiency. In this study, we cut down the preamble structure without zero-value guard symbol to reduce preamble resource overhead. However, the intrinsic imaginary interference from unknown data symbols around degrades the channel estimation performance. Therefore, we provide three different methods to remove or even utilize the intrinsic interference. Simulation results demonstrate that compared with the classical methods, the proposed approaches achieve approximate performance and save preamble resource.¹