Research On Phase Noise Compensation For High-frequency Multicarrier Communications

With the rapid development of wireless communication techniques,the communication frequency range is continuously expanding to higher frequencies,which further amplifies the non-ideal jitter of oscillators,causing phase noise to have a more severe impact on high-frequency signals compared to the low-frequency band.On the other hand,phase noise will destroy the subcarrier orthogonality of multi-carrier signals,and degrade system performance due to the introduced inter-channel interference and inter-carrier interference.This thesis analyzes the impact mechanism of high-frequency phase noise on highfrequency multicarrier communication,and further studies the reference signal transmission design,phase noise estimation,and compensation algorithm based on reference signal and data assistance for Orthogonal Frequency Division Multiplexing(OFDM)and Constant Envelope OFDM(CE-OFDM)systems.The main research content and conclusions of the paper are as follows.Firstly,this thesis analyzes the reasons for the variation of phase noise with carrier frequency and sorts out commonly used phase noise models in high-frequency communication..Based on this,this thesis analyzes the impact of phase noise on the system transmission performance of traditional multi-carrier waveforms under different channel conditions,modulation,and carrier frequency parameters by simulations.Secondly,this thesis focuses on the phase noise estimation and compensation algorithms in the OFDM system aided by the phase-tracking reference signal(PTRS).This thesis compares the compensation algorithms based on comb PTRS and block PTRS through simulation,analyzes the impact of pilot sparsity on system overhead and the performance of common phase error(CPE)compensation as well as the inter-carrier interference(ICI)compensation.To reduce the pilot overhead for the ICI estimation,this thesis proposes a data-aided ICI compensation scheme,which uses one PTRS block for ICI estimation and iteratively verifies the accuracy of phase noise estimation through the recovered data and reference sequence.The research results show that the improved scheme can still obtain certain performance gains while ensuring spectral efficiency,and this gain can be further amplified when channel coding is applied.Finally,this thesis investigates the reference signal design and phase noise compensation method suitable for CE-OFDM system regarding the issue of phase noise in CE-OFDM system.The impact mechanism of phase noise on the time-frequency domain signal of CE-OFDM is analyzed first,and the reference signal configuration and transmission method applied to CE-OFDM are established.The influence of different reference signal sequences on the peak-to-average power ratio(PAPR)and phase noise estimation performance of the CE-OFDM system is compared and analyzed.Furthermore,in order to mitigate the interference between the signal and the reference sequence caused by phase modulation,this thesis proposes a phase noise estimation and compensation algorithm which introduces a frequency-domain guard interval between data and reference block and applies joint-interference-and-phase-noise compensation to eliminate the interference of the signal on the phase noise estimation.Simulation results show that the proposed methods can effectively improve the signal quality of CE-OFDM reception.