Design And Implementation Of Medium Access Control For UE In 5G System

The fifth generation mobile communication(5G)system is now developing into a revolutionary standard in all aspects.With a new network architecture,it serves the highspeed,low latency and high reliability business requirements.Media access control(MAC)layer is an important part of terminal mobile communication.In the innovation of wireless communication technology,it has also been improved,so it needs to be researched and developed.Based on the major theme project "research and development and application of 5G terminal simulation equipment" of Chongqing Science and Technology Commission and the protocol of the 3rd generation partnership project release 15,this project deeply studies the information interaction between the MAC layer and the upper and lower layer protocol stacks.Meanwhile this project designs and implements the function of the MAC layer.The main contents and innovations of this thesis are as follows:1.The key functions of MAC layer are analyzed in detail,including random access,multiplexing and demultiplexing of protocol data unit,hybrid automatic repeat request and uplink and downlink resource scheduling.In the design,the concept of state machine is adopted,and the state of MAC layer is divided according to the functional process of MAC layer and the whole business process of protocol stack.According to the data interaction between the MAC layer and the upper and lower layer protocol stacks,the interface primitives are designed for the realization of each state,and the function and state transition of the MAC layer are realized through the primitives.The design makes the key functions of MAC layer can be realized,and makes each service flow,normative and relevant,and enhances the robustness and protocol consistency of MAC layer program.2.In the development and implementation part,this thesis uses multi-core digital signal processing as the hardware development platform,with the help of Code Composer Studio 5.5 software to realize the functions and states of MAC layer.In addition,this thesis puts forward specific schemes for the implementation of nul state,SEL state,IDL state,ACC state and con state,mainly including the implementation of interface primitives of various functions in each state and corresponding processing functions and processes.3.Build a test platform,design test cases to test and verify the above design.The specific test method is to carry the test information in the way of interface primitives to trigger the corresponding functions of MAC layer,and test whether the processing results can meet the protocol requirements.In this thesis,50 groups of test cases are designed based on the protocol.Through continuous debugging,optimization and improvement of the code,the test results show that the MAC layer can correctly achieve the functions of random access,multiplexing and demultiplexing of uplink and downlink data,hybrid automatic repeat request and calculating the time domain location of information,so as to complete the scheduling.The test pass rate reaches 100%,which verifies the correctness and rationality of the MAC layer design and the content of the implementation meets the agreement requirements of protocol.