An Opportunistic Scheduling Scheme On Maximizing Throughput In Wireless Broadcast/Multicast System

People’s increasing need of high-speed data service is driving the fast development of Multimedia Broadcast/Multicast Service (MBMS). High throughput achievement by efficiently exploiting limited bandwidth resources has become one of the key problems of high-data-rate service. Opportunistic multicast scheduling (OMS) techniques has emerged as an effective way to improve throughput by exploiting the multi-user diversity of unicast transmission and the broadcast gain of broadcast transmission, and it can satisfy users’QoS need of high-data-rate service.Since existing OMS schemes do not jointly exploit utilize user channel statistics and user channel state information (CSI), we propose an Optimized OMS. The key improvement of Optimized OMS scheme is that BS’s scheduling method is not only based on the consideration of current timeslot’s throughput by exploiting CSI, but also based on the consideration of maximal future timeslot throughput by exploiting user channel statistics. Simulations are operated to compare Optimized OMS scheme with the existing ones. Results show that Optimized OMS can achieve higher throughput by jointly utilizing user channel statistics and user CSI.Since existing OMS schemes such as Maximal OMS scheme does not take user fairness into consideration, we modify Maximal OMS scheme and propose a Parity-Based OMS. The key improvement of Parity-Based OMS scheme is that BS has to take users’data reception into account before assigning priority level to each user. For those users who have received fewer packets, BS raise their priority levels to some extent in an appropriate way. Simulations are operated to compare Parity-Based OMS scheme with the existing ones. Results show that Optimized OMS can achieve higher throughput by considering user fairness.