Optimization of energy consumption with hybrid cooperative NOMA for secure MEC

The widespread use of non-orthogonal multiple access (NOMA) has changed the traditional physical layer security limits on per-user transmission rates, with the attendant increase in complexity and system energy consumption. In view of this, a secure transmission method for mobile edge computing based on NOMA hybrid collaborative interference is proposed. Firstly, a multi-slot hybrid collaboration scheme is designed for each user data processing process for the task offloading problem. The scheme eliminates auxiliary interference signals transferred the offload task to local computing in the specified time slot. Then the scheme optimizes the total energy consumption of the system while ensuring fairness among users. Secondly, a closed expression for the system secrecy outage probability is derived. And the optimization problem is decomposed into three sub-problems. Finally, the block coordinate descent algorithm is used to iterate cyclically. With the objective of minimizing system energy consumption, the best offloading decision scheme for the user is obtained and compared with orthogonal multiple access and full offloading schemes. With reasonable time slots, the simulation results demonstrate the proposed solutions can well weigh the relationship between security and energy consumption. And it can effectively reduce system energy consumption while ensuring information security.