Research Of Resource Allocation Schemes For Multicast System In Heterogeneous Networks

Multimedia Broadcast Multicast Service is being extensively studied for the reason that it can effectively utilize precious frequency resource with them mode PTM(Point to Multipoint) and improve the frequency efficiency of the wireless communication system, which is raised to solve the traditional transmission mode of PTP(Point to Point) which leads to low frequency efficiency of resource. Resource allocation technology of multicast is one of the most important part in multicast system. Here we dicuss the resource allocation of multicast problem in single network and in heterogeneous networks. Therefore, the paper improves existing resource allocation and two resource allocation algorithm which are dynamic interval-based power allocation algorithm in single network and resource allocation scheme for multicast services with diversity in heterogeneous networks, is proposed. The main work is as follows:A dynamic interval-based power allocation algorithm in single network is proposed. In this paper, multicast scenario in single network is considered, which is considering two factors of computing complexity and system capacity. Firstly, the power interval is calculated by analyzing the constraint conditions of optimization function. Secondly, we reduce the power searching times by diminishing the power interval dynamically to reduce the computing complexity. Numerical results show that the improved algorithm can achieve the similar throughput as iteration power allocation with lower complexity.A resource allocation scheme based on QoS for multicast in heterogeneous networks, which comprise a conventional macrocell and a femtocell, especially when there are some multicast services with diversity is proposed. In the proposed algorithm, we adopt a reserved scheme to ensure the multicast with bad channel quality some subcarriers in interference area. Then we allocate the subcarriers considering the channel quality and multicast’s priority. Finally it allocate the power for subcarriers differently in diferent area, which lead to improve the system capacity. Numerical results show that the proposed algorithm achieve high throughput while guaranteeing the QoS for real-time and non-real-time service.