Research On Phase Noise Compensation In OFDM High Precision Ranging

The orthogonal frequency division multiplexing(OFDM),a particular modulation method,has been widely used in various broadband communication systems in recent years,including the popular high-precision wireless ranging system.Using the fast time-frequency conversion signal processing platform provided by OFDM technology,the high-precision wireless ranging system can overcome the defects of poor anti-interference performance,poor anti-noise performance and poor multi-path performance while retaining the advantages of traditional radio ranging.However,the high-precision wireless ranging system using OFDM technology is sensitive to phase noise,and as the wireless transmission frequency band increases,the influence of phase noise on the system becomes larger and larger,which cannot be ignored.Therefore,effective phase noise compensation technology is needed to compensate for the influence of phase noise on the ranging system and ensure the accuracy of the ranging system.To this end,this paper has conducted in-depth research on phase noise compensation techniques in OFDM high-precision ranging systems.For the phase noise,this paper firstly describes the statistical model of phase noise,and then analyzes and deduces the influence of phase noise on the orthogonal frequency division multiplexing system,including two aspects: one is the common phase rotation,and the other is the inter-subcarrier interference.Finally,the design of OFDM high-precision ranging system and the compensation method of phase noise in common OFDM systems are introduced.In order to further increase the phase noise compensation effect.In this paper,a phase noise compensation scheme based on neural network theory is proposed.By establishing a neural network transmission model and jointly tracking phase noise and channel,phase noise can be effectively estimated and the accuracy of ranging can be improved.The simulation results show that the proposed phase noise compensation scheme can better compensate the phase noise in the multipath channel environment.Secondly,in view of the slow convergence speed of the proposed phase noise compensation algorithm,this paper designs a new ranging sequence to reduce the dimension of the phase noise tracking matrix.The simulation results verify the effectiveness of the new sequence design,that is,using the new sequence,the convergence speed of the phase noise compensation algorithm can be greatly accelerated without reducing the accuracy of ranging.When the channel environment is poor or the ranging accuracy is high,a high complexity/optimal phase noise compensation algorithm is needed to effectively ensure the high precision performance of the ranging system.However,when the accuracy of the ranging accuracy is not strict,a low-complexity phase noise compensation algorithm can be considered to ensure faster calculation while ensuring high precision.Therefore,this paper proposes a phase noise compensation algorithm based on region quantization matching.The algorithm is constructed by two-stage region quantization codebook to obtain a series of phase noise trajectories.Then,a trajectory closest to the actual phase noise is selected in the area quantization codebook by a correlation method.The simulation results show that the proposed algorithm can achieve better phase noise compensation performance only with simple selection when the ranging accuracy is not strict.