Design And Research On Receiver For 60GHz Millimeter-wave Communication System

With the rapid development of society,the demand for high-speed wireless communication is increasing,especially in indoor short-range scenarios where users require higher data transmission rate and lower delay.Driven by this demand,many scholars have conducted a lot of research work and introduced various wireless LAN standards.However,the spectrum resources in the low frequency band are getting tighter and tighter,and there are abundant spectrum resources in the 60 GHz band.In this paper,we design and study the receiver of60 GHz millimeter wave communication system,mainly including synchronization and equalization techniques.Firstly,the development history and research status of the millimeter wave system are introduced,introduces several millimeter wave band communication standards,and gives an overview of the key technologies of millimeter wave receivers.Secondly,the overall structure of the millimeter-wave communication system is introduced.The propagation characteristics of the 60 GHz millimeter-wave radio channel are analyzed,and a channel model in this band is introduced: the IEEE 802.15.3c channel model,the mathematical expression of the channel impulse response of the model is given,the meaning of the parameters in the model is analyzed,and the power delay profile of some typical scenarios are simulated.Then the frame structure of the system is introduced,which mainly includes two parts: the preamble and the data block,then the overall design structure of the communication system in this paper is given.Then,the synchronization problem of receivers in 60 GHz millimeter wave communication systems is studied.For the symbol synchronization problem,the coarse synchronization algorithm based on threshold comparison is investigated in this paper.According to the system synchronization sequence characteristics,this paper proposes a coarse synchronization method based on sliding average filter,and the simulation results show that this method can obtain better coarse synchronization performance than the algorithm based on threshold comparison.For the carrier synchronization problem,this paper firstly introduces some data-assisted carrier synchronization algorithms,adopts a frequency offset estimation and compensation algorithm based on average of cross correlation for the system characteristics,and uses the guard interval between data blocks to perform residual frequency bias compensation on the basis of coarse frequency bias compensation.Finally,the equalization problem of 60 GHz millimeter-wave communication system is studied.Firstly,the zero-forcing equalization,MMSE equalization and decision feedback equalization are analyzed and compared with the performance simulation.The results show that the linear equalization is simple to implement with poor performance,and the nonlinear equalization has better performance but higher computational complexity.Therefore,this paper proposes a method to calculate the equalization coefficients using the protection interval to reduce the computational complexity.In addition,this paper also investigates a low-complexity judgment feedback equalization algorithm,and for its poor performance under high-order modulation,this paper proposes an improved algorithm by using signal-to-noise ratio estimation and fitting the symbol error rate,and the simulation results show that the proposed algorithm has significantly improved the system performance.Finally,this paper studies and compares various channel estimation methods,and gives a channel estimation method based on Golay complementary sequence.