Research On Signal Detection And Recovery In OQAM/FBMC System

Filter bank multicarrier with offset quadrature amplitude modulation(OQAM/FBMC)is one of the most potential modulation technology in mobile communications in the future.OQAM/FBMC uses a prototype filter with good time-frequency domain focusing property,which has significant advantages such as low spectral side lobes and strong asynchronous transmission capability.However,OQAM/FBMC only satisfies the orthogonality in the real field,resulting in the inherent imaginary interference,posing many challenges for the signal detection and recovery,such as complex pilot design and high overhead.Therefore,exploring the intrinsic nature and characteristics of the OQAM/FBMC system,this paper proposes the signal detection and recovery method that simplifies the pilot design and reduces the pilot overhead.Firstly,for the characteristics that the demodulated signals on the OQAM/FBMC single carrier under the ideal channel could be clearly classified in the two-dimensional complex plane,the idea of detecting classification decision is proposed.This idea provides a classification perspective to handle the detection and recovery of OQAM/FBMC system signals.Through theoretical analysis and a large number of simulations,the validity of the idea in the additive Gaussian white noise channel is verified.Then,the detection classification decision(DCD)method under the OQAM/FBMC flat channel model based on the above ideas is proposed.The detection classification and classification decision module replaces the traditional channel estimation and channel equalization and other modules,which simplifies the module at the receiver.In addition,only one column of random pilots is transmitted,and there is no need to consider the imaginary interference from the surrounding symbols,which not only effectively reduces the complexity of the pilot design,but also greatly reduces the pilot overhead.Finally,in order to further reduce the bit error rate(BER),Cyclic-Detection Classification Decision(C-DCD)method is proposed.The method could effectively improve the accuracy of signal recovery by the secondary classification decision.The simulation indicate that the signal detection and recovery method based on C-DCD has the same BER performance as the classic Interference Approximate Method(IAM).And superior performance in terms of instantaneous power signal distortion.In this essay,for the problem of complex pilot design and large overhead in the OQAM/FBMC,the signal detection and recovery method based on detection classification decision is proposed,which simplify the pilot design and reducing pilot overhead and improves the spectrum utilization.