Abstract—This paper proposes two scheduling algorithms for subcarrier allocation of OFDM relay system, Enhanced Two-Hop Adaptive Proportional Fairness (E-THAPF) and User-Number-Dynamic Two-Hop Adaptive Proportional Fairness (UND-THAPF), aiming to improve the performance of the traditional Two-Hop Proportional Fairness (THPF) scheduling algorithm. By modifying the priority of the two hops in THPF in an adaptive fashion, ETHAPF and UND-THAPF can optimize the subcarrier allocation dynamically despite of the subcarriers fluctuation, and thus can keep the system flexible and stable. Moreover, the factor α in the dynamic index of UND-THAPF is made adaptive to the change of the number of users. Simulation results show that the proposed algorithms achieve a better compromise between system fairness and spectral efficiency. In particular, while E-THAPF is designed to be adaptive to different sub-channel conditions, UND-THAPF performs even better for taking number of users into account in the optimization.

Index Terms—OFDM, DF relay, E-THAPF, UND-THAPF, spectral efficiency

Cite: Cui-Qin Dai, Hang-Jun Che, Fang Lin, and Qian-Bin Chen, "Adaptive Subcarrier Allocation for OFDM Relay System," Journal of Communications, vol. 8, no. 1, pp. 1-7, 2013. Doi: 10.12720/jcm.8.1.1-7