Research And Implementation Of Adaptive Modulation Coding Technology Based On OAI

With the rapid development of wireless communication and the increasing popularity of wireless devices,wireless communication has higher and higher requirements on communication rate,in order to realize low-latency,high-reliability enhanced mobile broadband wireless transmission,in 5G application scenarios "Enhanced mobile bandwidth" has become a research hotspot.At the same time,the research on "Gigabit LTE" based on the current long term evolution(LTE)system has a better implementation basis.To achieve high-speed transmission of "Gigabit LTE" system,this paper researched and implemented adaptive modulation coding technology(AMC)in the link adaptation technology of LTE.This paper expounds the research background and significance of AMC technology,and the research status of AMC technology in LTE system.Introduced the physical layer frame structure of LTE system and the TDD frame structure oriented to 5G are in detail.Introduced the basic principles of OFDM,MIMO,high-order modulation technology.Finally,the OAI source platform is introduced in the second chapter.Based on the classification of signal-to-noise ratio(SNR)and the effective signalto-noise ratio mapping algorithm,explored the role of effective signal-to-noise ratio in adaptive modulation and coding.A mapping optimization algorithm based on MMSE criterion for effective SNR is proposed,which is to optimize the adjustment factor of MIESM algorithm.Then,the rationality and effectiveness of the improved mapping algorithm are verified by the SNR-BLER performance curve.Based on the LTE system downlink model,based on the improved effective SNR mapping algorithm,the CQI solution process and SNR-CQI map are given.Further analyzed the throughput performance considering hybrid automatic retransmission.Finally,aiming at the problems existing in the current MCS mapping algorithm,propose a novel reinforcement learning-based MCS selection scheme.Predicte the MCS selection of future channel states based on historical SNR and MCS mapping values.Improve real-time performance and reducing mapping to improve LTE system throughput.The system simulation results show that,in the same propagation scenario,the system average throughput of the proposed scheme is significantly better than the fixed threshold based SNR-MCS mapping scheme,and the computational complexity is significantly better than the linear SNR-MCS mapping scheme based on CQI reporting.It is proved that the proposed algorithm optimizes the system throughput under the same conditions and reduces the computational complexity.At the same time,this paper gives the updated SNR-MCS mapping scheme,which can be used to optimize the real LTE system base station.