Resource allocation for multiple description coding multicast in OFDM-based cognitive radio networks

The resource allocation scheme for the multiple description coding multicast (MDCM) in orthogonal frequency division multiplexing (OFDM-based) cognitive radio network (CRN) is studied in this paper, aiming at maximizing the total throughput of cognitive radio (CR) users, with constraints on sum transmit power, the maximal receiving rate of each CR user and the maximal total interference introduced to each primary user. With the analysis of the model, an algorithm, which consists of subcarrier assignment and power allocation using the sub-gradient updating method, is proposed. Meanwhile, to reduce the complexity, a suboptimal algorithm is also proposed, which divides the total transmit power into small slices and allocates them one by one. Moreover, the suboptimal algorithm is modified by adding an advanced water-filling process to improve the performance. The simulation results obtained in this paper show that the system throughput using the MDCM scheme is much higher than that using the conventional multicast (CM) scheme and the performance of the proposed suboptimal algorithms can approximate the MDCM scheme very well.