Research On High Reliability And Low Latency Wireless Communication Technology Based On Sparse Vector Coding

In order to support the Ultra-Reliable and Low-Latency Communication(URLLC)application scenario in the 5th Generation(5G)mobile communication technology,the 3rd Generation Partnership Project(3GPP)proposes to transmit short data packets with an error rate of 10-5 within a transmission period of 1 millisecond.Therefore,sparse vector coding(SVC)came into being as a new scheme to support short data packet transmission.Its main idea is to map the input bits into the sparse vector and transmit it after random spreading.The resulting underdetermined sparse system is decoded by greedy recovery algorithm,which makes up for the shortage of the traditional wireless communication channel coding scheme in the reliability of short data packet transmission,and ensures better reliability and lower delay.Therefore,this thesis is based on SVC and combined with constellation rotation to deeply study the coding scheme for short data packet communication,and is committed to further improving the reliability and time delay of short data packet transmission.The research content and main work are as follows:(1)The theoretical basis of SVC technology—Compressed Sensing(CS)theory is introduced,and the core content of CS,including signal sparse representation,measurement matrix design principles and reconstruction algorithms,is systematically described.The basic principles of SVC are sorted out,and the original SVC,enhanced SVC,and SVC based on constellation rotation technology are analyzed from the coding and decoding principles.(2)In order to further improve the reliability of SVC technology,the main factor affecting the reliability of SVC,that is,the Minimum Euclidean Distance(MED)among superimposed constellations,is first deduced through problem construction.Based on this,a Uniquely Decomposable Constellation Group(UDCG)with maximized MED is designed to ensure the superimposed constellation based on UDCG has the largest MED.(3)According to the designed UDCG,a UDCG-based SVC(UDCG-SVC)coding scheme is proposed.In UDCG-SVC,the constellation contained in the UDCG is used as the SVC modulation rotation constellation,and the modulation bit stream is mapped to the non-zero position of the sparse vector through the constellation in the UDCG.After random spreading,the transmission vector carried on the resource block has unique decomposable characteristics.From the aspect of codebook design,the difference between UDCG-SVC and SVC based on constellation rotation technology is mainly introduced,and the unique decomposability of UDCG-SVC is proved.(4)The performance of UDCG-SVC proposed in this thesis is analyzed.Firstly,the capacity,Block Error Rate(BLER)and time delay of UDCG-SVC are analyzed theoretically.Then based on MATLAB simulation,UDCG-SVC is compared with original SVC,enhanced SVC,and SVC based on constellation rotation technology.The advantages of UDCG-SVC in terms of capacity and reliability are verified,especially in the case of high-order modulation,the advantages are more prominent.The simulation results can prove the effectiveness of theoretical derivation.