Research On Synchronization And Channel Estimation Technology Of FBMC System

Filter Bank Multicarrier(FBMC)technology can effectively resist inter-symbol interference and inter-subcarrier interference by designing prototype filters with good performance,and has the advantages of low out-of-band power and high spectrum utilization,which can better used in large-capacity,ultra-high-speed wireless communications,it has become a strong candidate for multi-carrier technology in 6G communications.Facing the diversified transmission requirements of future communication services,FBMC technology still has certain limitations.Since there is no cyclic prefix in the FBMC system,the time-frequency deviation will seriously affect the performance of the system and increase the difficulty of signal demodulation.At the same time,the non-strict orthogonality of the FBMC system leads to the existence of false interference,which requires channel estimation in the complex domain,while the traditional channel estimation technology has poor performance in the FBMC system.Therefore,it becomes very important to design better synchronization and channel estimation algorithms at the receiving end.This article focuses on the FBMC system,focusing on the synchronization technology and channel estimation technology at the receiving end to carry out the analysis and design of the algorithm,and at the same time use the Matlab simulation platform to verify the algorithm.Aiming at the synchronization technology of FBMC system,this paper proposes a data-assisted timing synchronization scheme.The algorithm uses the ZC sequence with strong autocorrelation to construct a new pilot structure for synchronization processing.First,perform cross-correlation operation between the received sequence and the locally known ZC sequence,determine the timing synchronization point through peak detection,and complete coarse timing synchronization and compensation;then use the least square method to construct a new timing measurement function to perform fine timing synchronization.Accurately locate the starting position of the data frame to improve the accuracy of timing synchronization.Through simulation,it can be known that under the same channel environment,the improved algorithm has superior timing synchronization performance.Aiming at the channel estimation technology of FBMC system,this paper proposes an improved algorithm based on interference cancellation.The improved algorithm uses block pilots for channel estimation.The pilot sequence occupies two consecutive FBMC symbols.The first column carries pilot data information,and the second column carries auxiliary pilot information and zero value information.The improved algorithm sets a reasonable window range to calculate auxiliary pilots,and at the same time,combines time-domain filtering to eliminate most of the inherent interference and channel noise interference introduced by the surrounding data symbols,which improves the accuracy of channel estimation to a certain extent.Compared with the traditional algorithm,the improved algorithm has a smaller bit error rate and mean square error,while ensuring the transmission efficiency of the system.