A Joint Power-Aware Spectral Efficient Chunk Allocation, Relay Selection, and Energy Efficient Power Control in OFDMA-PNC Communication

In recent years, besides spectral efficiency (SE), improving energy efficiency (EE) has become a crucial optimization metric in radio resource allocation (RA). This work addresses the joint problem of chunk-level spectral efficient chunk allocation, relay selection, and a subcarrier-level energy-efficient power control algorithm in a multi-user multi-relay orthogonal frequency division multiple access-physical layer network coding (OFDMA-PNC) system. The resulting mixed-integer nonlinear programming (MINLP) problem is NP-hard and computationally intensive. To manage complexity, chunk-level algorithms are used for subcarrier allocation and relay selection. Two MILP solvers and two heuristics handle chunk and relay allocation via Alternating Optimization (AO) method, while power levels are optimized using a convex optimization solver with the Dinkelbach (DKB) algorithm. Simulation results indicate that in a mobile network where user equipment operates at a maximum consumed power of 33.6 dBm, our proposed joint chunk allocation and relay selection method outperforms the heuristic approach, achieving 85% higher SE and a 47% improvement in EE. Additionally, our proposed suboptimal power control algorithm achieves results closely matching the optimal solution obtained using the DKB algorithm, demonstrating its effectiveness in balancing performance and computational efficiency.