Multimedia Mobile Communication Systems, Radio Resource Management Strategy Study

The Radio Resource Management is a key technique and a research hot spot in the 3G or future mobile communication system. It includes handoff control, call admission control, power control, packet schedule, load control, and mobility management so on. The strategy can be used to guarantee the required quality of service (QoS) of various calls in multimedia communication system, optimize the available resource in the system, and improve resource utilization. The handoff control scheme, the call admission control scheme and the power control scheme are discussed in the WCDMA system in this paper, divided into four chapters. The chapter provides a detailed discussion of wireless resource reservation schemes. An improved resource reservation mechanism is applied in the handoff strategy in hierarchical cell structure (HCS) in the third sector. The resource reserved for handoff calls can be also used for new calls according to the mobility and network status in this scheme.The handoff control strategy is researched in this chapter. The capacity in the present cellular system don't meet the need of the changing load in metropolitan location, such as airport, railway station. The HCS can be used to solve it. A handoff control scheme based on the area of a cell and the bit energy to interference density ratio is proposed in this section, which is suited for hierarchical cell structured WCDMA system. The simulation results suggest this scheme improve the block probability, while the dropping probability is little variable.Chapter 4 proposes a call admission control scheme in which the target handoff base station is predicted. The scheme is simulated in metropolitan environment in WCDMA system. The results indicate the very obvious improvement of the probability of succeeding in communication and the system QoS.In Chapter 5,we research on the power control scheme in wireless CDMA data communication system. Goodman proposed a power control strategy, in which the quality of service of each mobile station is referred to as the utility function. On the basis of the Goodman's work, we introduce a new price function based on the multiple address interference and the distance between the terminal and the base station. The price function can adapt to the system status. The simulation results manifest that the power control strategy with the price function advances the utility of the terminal, reduces the transmitting power in the mobile station, and saves the battery energy to prolong the speech time of the subscribers.The dissertation is summarized in the last chapter.