Preamble Power Optimization Based on Intrinsic Interference Utilization for OQAM/FBMC Channel Estimation

Abstract

Benefiting from high spectral efficiency, agility of carrier aggregation and support for asynchronous transmissions, offset quadrature amplitude modulation based filter bank multicarrier (OQAM/FBMC) is being developed as an attractive alternative to cyclic-prefix based orthogonal frequency division multiplexing (CP-OFDM) as the air interface technology for future communications. However, its non-orthogonal nature results in intrinsic interference among symbols and subcarriers, which makes channel estimation in OQAM/FBMC significantly more difficult than that in CP-OFDM. In this paper, we propose a novel preamble design method based on intrinsic interference utilization for OQAM/FBMC channel estimation. Specifically, we build a preamble by triplets of subcarriers, each of which is determined by a preamble power optimization problem that minimizes the channel estimation mean square error (MSE) at the central subcarrier. We derive the optimal closed-form solution by exploiting the linearly dependent relationship between preamble symbols and intrinsic interference weights. Moreover, extensions to multiple-input multiple-output (MIMO) setup capable of improving both spectral efficiency and channel estimation performance are investigated. Theoretical analysis and simulation results show the superiority of the proposed preamble design method over the conventional methods in terms of channel estimation MSE, bit error ratio (BER) and peak-to-average power ratio (PAPR).