Research On Resource Allocation Algorithm Based On SCMA Multiple Access Mechanism

Nowadays,the number of mobile communication access devices and the scale of data have increased exponentially,and the traditional communication system with orthogonal multiple access technology can hardly meet the current demand of access devices.The main objective of this paper is the resource allocation algorithm based on SCMA multiple access mechanism,and the main work is as follows:A brief introduction is given to the current status of domestic and international research on some new multiple access technologies including SCMA technology,and the background and significance of the research objectives of this topic are indicated.Then the principles of SCMA technology and related technologies are explained,including some new multiple access technologies,the construction of SCMA downlink system models,some schemes for SCMA codebook design,and finally some classical resource allocation schemes are analyzed.Two algorithms for resource allocation in SCMA systems are proposed by modelling the SCMA downlink system.The total capacity of the transmitted signal in a communication system is an important indicator for judging the overall communication scheme.Using the SCMA downlink system model created as an application communication scenario,a resource allocation scheme for maximizing the capacity in a communication system is proposed by jointly optimizing the subcarrier allocation and power allocation scheme,by setting the user transmission rate in the system to need to By setting the minimum user transmission rate required to meet the minimum user quality of service rate,the total capacity of the user transmission data in the system is maximized and the fairness of the users in the system is also enhanced.The use of the proposed algorithm can effectively increase the total capacity of the SCMA system and improve the user fairness.When solving the problem,the integer constraints on the subcarrier allocation matrix are relaxed to continuous constraints using a relaxation algorithm by adding a gauge function.Then,the optimized iterative block continuous lower bound minimization BSUM algorithm is applied to converge to the local minimum of the relaxation problem.During the solution process,the subcarrier allocation matrix and power allocation matrix are cyclically updated.When only one matrix is updated during the update process,the other remains unchanged.This transforms the problem into a convex optimization problem and obtains the local optimal solution of the relaxation problem through iterative algorithms.The proposed algorithm is superior to the traditional random code book average power allocation algorithm.User fairness performance is extremely important in communication systems.A resource allocation scheme with the objective of maximizing the energy efficiency of a single user is proposed,and the algorithm is implemented in the created SCMA downlink system model.As solving the entire large optimization problem is too complex,a fixed variable approach is used to solve the problem by first processing the random allocation of power to the users in the system,and according to the power completed by the user allocation A greedy algorithm is used to select the codebook of the corresponding user,and then the codebook is allocated to each user in the system.In the power allocation phase,the codebooks allocated in the codebook allocation phase are used to transform the power allocation problem into a power allocation problem for a single user under a fixed codebook,and the optimization problem is solved by transforming the Lagrangian pairwise function to obtain the optimal allocated power for a single user under a fixed codebook,after which the user codebook and power allocation problem are repeated.The codebook is selected with the objective of maximizing the transmission signal capacity of a single user,which can effectively improve the user fairness performance in the system,and in the application scenario,maximizing the energy efficiency of a single user can also improve the energy efficiency of the whole transmission system.