Satellite Diversity Slotted ALOHA Protocol Based On Channel Contention Resolution

The Internet of Things is an important application scenario in the fifth generation of mobile communications,and machine-to-Machine(M2M)communication is a typical paradigm for the Internet of Things.It is widely used in smart homes,telemedicine,logistics tracking,and other important industries,which will inevitably lead to a largescale increase in the number of M2 M communication terminals.As for conventional communication system,when a large-scale M2 M terminal device tend to access,the radio access network will be overloaded,resulting in increased access delay and more energy consumption for M2 M communication.Therefore,this paper studies the application of satellite communication system to transmit M2 M communication data.Due to the requirement of high data transmission rates and large-scale device support in nextgeneration communication system,it has a great impact on the design of multiple-access protocols.Therefore,it is necessary to conduct in-depth research based on existing access protocols.Firstly,this paper introduced the domestic and abroad application status of satellite M2 M systems.In this context,the research status of multiple access technologies are discussed,combined with the research situation in China and foreign countries,from the ground and the satellite The access technology of M2 M system is analyzed,and the advantages and disadvantages of different technologies are compared.At the same time,the development trend of access technologies in satellite M2 M systems is analyzed in combination with examples to provide an access solution for the next generation communication systems based on satellite Internet of Things in China.This is referred as theoretical support of communication development in China.In the context,after investigation and comparison of existing access technologies,this paper focuses on the access scheme based on slotted ALOHA protocol that is suitable for satellite communications.Then it introduces the M2 M type business model and iterative interference cancellation technology,which lays a theoretical foundation for the following research on access protocols for M2 M service types.Next,an access scheme is introduced which combines the traditional diversity time slot ALOHA protocol with a continuous interference cancellation algorithm,satisfying the requirement of the M2 M system and its characteristics of bursty traffic and short data packets,i.e.contention rsolution diversity slotted ALOHA protocol(CRDSA).Meanwhile,this paper deduces the throughput ceiling.The analysis compares CRDSA with the traditional access protocol from both the MAC layer and the physical layer.In this case,the system throughput rate is significantly improved,and the packet loss rate is greatly declined the normalized load is less than 1.Finally,aiming at the throughput boundary limitation deduced from the above problems,this paper further reduces the packet loss rate by setting the repetition rate distribution of packets.Through the simulation analysis,the desired effect is achieved.That is,in the simulation analysis of the MAC layer,when the normalized load is less than 1,the system throughput rate is further improved,and the packet loss rate is reduced.A physical layer simulation analysis was performed for this protocol,and a scheme combining the irregularly repeated time slot ALOHA protocol with the LDPC code was proposed,and the data packet coding mode was improved,thereby improving the antinoise performance of the access protocol.