Abstract:

A proportional fairness resource allocation algorithm, including both subcarrier assignment and power allocation, is proposed in multicast orthogonal frequency division multiplexing (OFDM) systems. The former is achieved by modifying the existing unicast subcarrier assignment algorithm, whereas the latter is implemented as allocating power via dual-bisection iteration, which is capable of obtaining the optimal allocation results when subcarrier assignment is determined. Simulation results demonstrate that the proposed resource allocation algorithm can achieve perfect fairness among users while maintaining the efficient capacity performance. It is also shown that multicast results have remarkable capacity enhancement comparing to unicast despite proportional fairness constraint. However, the capacity gain has a close relation with rate proportion and the number of multicast group.

Key words: orthogonal frequency division multiplexing, multicast, resource allocation, proportional fairness