Research On Single Carrier Block Transmission System With Multiple Antennas

With the rapid development of society,the requirements on the real-time information transmission and transmission rate are getting higher and higher.The main challenge for broadband wireless communications is how to overcome the multipath delay expansion of wireless channels.Single carrier-frequency domain equalization is an effective way to combat effects of multipath channel conditions and to overcome high Peak to Average Power Ratio of Orthogonal Frequency Division Multiplexing system.Single carrier-frequency domain equalization is suitable for transmission scheme with power constrained devices.When deploying multiple antennas,SC-FDE system can further enhance the reliability of the transmission link.This paper first introduces the influence ofwireless channel on digital signal and wireless communication system.It points out the time and frequency duality of broadband wireless channel.On this basis,the SUI-3 channel model used in the simulation is analyzed.Then,the MIMO technology and space-time coding technology are introduced.the coding and decoding method of Alamouti scheme is analyzed,Then the general space-time block codes are gotten from the Alam-outi scheme.The space-time block codes of real signals are extended to the complex space-time block codes.Finally,the performance simulation curve of space-time block codes is analyzed.After that,the space-time block codes can be used in the frequency selective channel.Based on the establishment of a single carrier frequency domain equalization system,the channel fre-quency domain equalization algorithms are studied and simulated,including frequency domain linear equal-ization ZF algorithm and MMSE algorithm,mixed decision feedback equalization(HDFE)algorithm,noise prediction decision feedback equalization(HDFE-NP)algorithm and the Residual inter symbol interference cancellation equalization(MMSE-RISIC)algorithm.The bit error rate performance of MMSE algorithm is better than ZF equalization because of taking into account the influence of noise and avoids the zero-crossing error.Then,the performance of the nonlinear equalization algorithm is compared and analyzed.The nonlinear equalization algorithm is superior to the linear equalization algorithm in the bit error performance.Especially in the case of high signal-to-noise ratio,the nonlinear equalization improves the performance of the system In the nonlinear equalization algorithm,HDFE-NP algorithm is more flexible and suitable for application.Under the same performance condition,HDFE-NP algorithm has less computational complexity.Then,the system model of SC-FDE system and OFDM system is compared and analyzed.The similarity and difference are analyzed.The basic principle of SC-FDE system and the single-carrier frequency domain equalization system Coding scheme is expounded.A scheme of combining single carrier frequency domain equalization system and space-time coding multi-antenna technology is designed.The simulation results show that the multi-antenna single carrier frequency domain equalization system improves the performance of the system significantly compared with single antenna frequency domain equalization system.the orthogonal frequency division multiplexing technology and single carrier frequency domain equalization technology are compared from the peak to average ratio,the system channel capacity,bit error rate and the frequency offset and phase noise sensitivity.Under the condition of frequency selective channel,the performance of the two systems is simulated and compared.The performance of the two schemes is almost coincident with the low signal-to-noise ratio.However,with the increase of the signal-to-noise ratio,the performance of the single carrier frequency domain equalization system significantly better than OFDM systems.In the aspect of overcoming saturation amplifiers,frequency offsets and phase noise,the SCFDE-STBC system is better than the SCFDE system and the OFDM-STBC system.Finally,the work of this paper is summarized,and the further research direction of single carrier fre-quency domain equalization multi-antenna technology is discussed.