Research On 5G Satellite Link Adaptive Modulation Based On Subband Weighted COI And Memory Multiplexing IDMA

The terrestrial wireless mobile communication system and the satellite mobile communication system are important components of the global next-generation communication network system.This article aims to combine the two advantages of terrestrial satellite communications to improve the adaptability of mobile communication systems to the growing business needs and the reusability of technology.For the goal of air-space integration,through the L2S simulation of the mobile communication system The research of key technologies such as the link adaptation technology of the interface and the multiple access method realizes the link adaptation function of the entire communication.The research contents of this paper are as follows:Firstly,the link adaptive technology and the broadband satellite channel model in the communication system of the broadband satellite system mobile communication system are studied,and the physical layer system parameters,slot structure and physical channel resource allocation that are suitable for the integrated heaven and earth channel system are set Based on the characteristics of satellites,a wideband satellite channel was modeled,and a satellite communication simulation platform based on 5G NR was built.Secondly,based on the incompleteness of the original L2S simulation interface parameters and the lack of modeling of the satellite channel,the method of establishing the ? value was improved,and the satellite channel model published by the ITU and the existing ground channel were recalibrated to supplement the L2S parameter interface.Use the validation channel for fitting.The simulation results show that the average fitting threshold error is about 0.2dB,most of which are lower than about 0.1 dB,which is far lower than the 0.4dB specified in the 3GPP protocol.The MCS obtained by using sub-bands weighted CQI and ? parameter to get feedback channel status is also more adequate than the existing L2S parameters of LTE.This is conducive to further research on the integration of heaven and earth,and improves the spectrum utilization in the link feedback process.Finally,after improving the spectrum resources of the link,the storage resources of the interleaver in the multi-access technology are studied to further solve the current shortage of satellite resources.Compared with LTE,5G communication technology and satellite communication have terrestrial communication.For the differences in scenarios and business requirements,in view of the original DVB-RCS2 protocol,only the maximum transmission unit was specified.A variable information transmission sequence was designed based on 5G.The interleaver is an important unit of the IDMA communication system.Based on the memory multiplexing mechanism,a hybrid multilevel tree interleaver with low memory requirements is designed.Compared with the traditional interleaver,it only needs to occupy the original 1/N memory resources.(Where N is the number of interleavers),it can reach the low calculation complexity of logN K(K is the number of user accesses)without causing loss of system performance bit error rate.In the follow-up,the possible effects of the preprocessing process were mentioned.A dynamic matching algorithm was used to make up for the shortcomings of the new interleaver preprocessing delay,which improved the performance by 17%and further optimized the design of the new interleaver.