Research On Frequency Estimation For Millimeter Wave Massive MIMO System

With the increase of wireless users and users' increasing demand,the mobile data traffic achieves the explosive growth.It is difficult to meet the requirement of large amount of data transfer for traditional microwave frequency band due to its limited spectrum resources,the millimeter wave frequency band which has rich spectrum resources becomes the hot topic of the next generation mobile communication.Frequency offset has a great influence on the performance of wireless communication systems,compared with traditional microwave communication,high frequency mm-wave communication is more sensitive to the frequency offset caused by random phase noise produced by the instability of the crystal oscillator,so study on frequency offset,especially phase noise,is crucial in millimeter wave communication.In the paper,the channel characteristics of millimeter wave communication are introduced briefly,then we discuss the effects of frequency offset and phase noise on the performance of the MIMO-OFDM system,concluding that the influence of frequency offset and phase noise on the received signal can be divided into two parts: common phase error and inter carrier interference.Then the BER performance of MIMO-OFDM system with phase noise is simulated by using BPSK,QPSK and 16 QAM modulation,which verifies the necessity of phase noise compensation in millimeter wave MIMO system.In the paper,the channel characteristics of millimeter wave communication are introduced briefly,then we discuss the effects of frequency offset and phase noise on the performance of the MIMO-OFDM system,concluding that the influence of frequency offset and phase noise on the received signal can be divided into two parts: common phase error and inter carrier interference.Then the BER performance of MIMO-OFDM system with phase noise is simulated by using BPSK,QPSK and 16 QAM modulation,which verifies the necessity of phase noise compensation in millimeter wave MIMO system.At last,this paper discusses the joint estimation and elimination algorithm for phase noise and carrier frequency offset.The millimeter wave massive MIMO system model under the condition of different oscillators at both the receiving and transmitting end is established.A LS-based common phase noise and frequency offset estimation and compensation algorithm and a EM-EKF-based phase noise,frequency offset and channel response estimation algorithm are proposed and analyzed.Additionally,the BER performance of LS-based and EM-EKF-based algorithm under the condition of MIMO and massive MIMO system are simulated,which verifies the superiority of EM-EKF algorithm.