Downlink Packet Scheduling Technologies Deploying Adaptive Antenna Array In Broadband Wireless Access Networks

The 3rd Generation mobile networks can not satisfy the requirement of multimedia services, so it is necessary to develop new mobile technologies to provide higher capacity and higher throughput services to users. So far, research on beyond 3G technologies is widely spread around the world.This disertation presents research results on the performance of PS (Packet Scheduling) algorithms with adaptive antenna array technologies in OFDM systems. Our aim is to analyze the combination of time diversity, frequency diversity and antenna diversity and find the best combination of these diversity technologies.Current research on PS technologies is focusing on some specific algorithms, while it has not stated the root reasons. For wireless communication systems, there exsists three root reasons which should be taken into consideration when designing PS algorithms. The first reason is that the 'uncertainty' of the traffic, the second one is the 'uncertainty' of the wireless channel. In OFDM, the channel's uncertainty exists in both time and frequency domain. The third one is the fairness. PS should consider the users' request of throughput and delay, in order to provide fair and differentiated services to different users. This disertation will analyze PS architecture and algorithm from these three root reasons. PS is to make use of these factors to improve system performance.The main work and contribution of this disertation is:- Modeling and simulation of wireless broadband communication systems is summerized. Simulation results are shown. This provides a comprenhensive view on simulation of wireless networks.- Slot based PS algorithms are investigated. And their performance in OFDM systems is also compared and analyzed. Three effects, which is 'user number effect', 'PS gain effect' and 'PS fainess effect', are analyzed. This will give more insight into PS algorithm research.- Propose OPF (OFDM Proportional Fair) algorithms. OPF can significantly improve system delay and throughput.- Propose IOPF (Improved OFDM Propotional Fair) algorithm. IOPF uses packet delay to decide which user will be served. And the comparion of IOPF with other algorithms is made and the simulation results are presented. Window selection strategies of IOPF have been analyzed for different services. IOPF shows better performance on delay and throughput compared with other algorithms.- Propose and compare three types of AAA-BF (Adaptive Antenna Array Beam Forming) Algorithms for forward link. And their performance under different scenarios is tested. - Investigate the combination of AAA and PS. It is stated that there exist three types of combination: (1) PS selects user without AAA and PS serves it with AAA; (2) PS select user with AAA and PS serves it with AAA; (3) Use SDMA (Space Division Multiple Access) to select user(s), and AAA serves user(s). Perfomance of these three schemes have been compared. This provides deeper insight into the combination of PS and AAA.