Adjustable subcarrier allocation for spectral efficiency and user fairness in 3GPP LTE downlink systems

In this paper, adjustable subcarrier allocation algorithm is proposed for both system spectral efficiency and user-throughput fairness (or throughput requirement). There exists trade-off between two performance metrics. The proposed subcarrier allocation method can easily coordinate system performance between spectral efficiency and user-throughput fairness. To achieve adjustable goal, we define cost function combined by adjustable weightings to the terms of both spectral efficiency and user- throughput fairness. Based on 3GPP LTE downlink system model simulations, we can show that spectral efficiency mode in the proposed algorithm can achieve much lower outage probability than Wong´s algorithm, which emphasizes spectral efficiency, with similar total spectral efficiency and throughput fairness. Also the user requirement-emphasized mode in the proposed one can achieve better performance than You´s algorithm, which emphasizes user data rate requirements, in terms of spectral efficiency, outage probability, and fairness pattern.