DFT Spreading-Based Low PAPR FBMC With Embedded Side Information

Low-complexity overhead and very small side information (SI) are virtues of the low peak-to-average-power ratio (PAPR) filter bank multicarrier [Low PAPR FBMC (LP-FBMC in short)], which has been recently proposed. However, the SI is an annoying burden because it needs a complicated system design, irrespective of its size. In this paper, we propose an SI-embedded LP-FBMC that does not separately transmit SI but embeds it in the transmitted signal in a specific way while preserving the PAPR and bit error rate (BER) performance. The approach is motivated by a property of the LP-FBMC where demodulation by even an incorrect SI does not change the signal constellation. We embed the SI in the intentional phase rotation of the constellation without additional energy or bandwidth. The phase rotation differs according to the SI and is common to all data symbols in each LP-FBMC subframe. In the receiver, we remove data symbol-dependent phase terms of the decision variables (DVs) by taking the fourth power and detect the SI embedded in the remaining phase term. Simulation results reveal that the BER of the SI-embedded LP-FBMC is almost the same as that of the perfect SI case when there are an acceptable number of data symbols for SI estimation. We also devised a complexity-reduced implementation for the additional processing required for the proposed SI embedding and detection schemes.