Joint Computation Offloading and Resource Allocation for NOMA-Enabled Industrial Internet of Things

In Industrial Internet of Things (IIoT), in order to satisfy the requirements of delay-sensitive service, devices with limited computing resources could offload computing task to edge server via wireless network. However, limited spectrum resource restricts the computation offloading of massive devices and may cause high transmission delay. Non-orthogonal multiple access (NOMA) is a promising technique to handle the issue which allows multiple devices to share the same frequency resource simultaneously. Thus in order to improve spectrum efficiency, this paper investigates computation offloading in NOMA-enabled IIoT. Specially, we consider co-channel interference in our model which complicates network spectrum resource allocation. A computation offloading scheme is designed by solving the minimum total completion delay problem which jointly optimizes computation resources allocation, transmission power allocation and subchannel assignment. In order to reduce the computational complexity, we decompose the original problem into three subproblems and propose an iterative algorithm based on optimization theory and many-to-one matching. Simulation results show that compared with orthogonal multiple access (OMA) based method, our method outperforms in total completion delay and network transmission rate.