Scheduling Algorithm Design In Future Wireless Communication Systems

As the demand of mobile services is growing, more advanced wireless transmission technology and network optimization ideas are needed. OFDM technology can effectively against inter-symbol interference caused by multi-path Propagation , and has become one of the core technology in the future high-speed wireless communications; CDMA technology as the core technology of 3G systems, has competition with indisputable force because of its good performance; multiple-input multiple-output (MIMO) technology can increase the spectrum efficiency and improve the system data rate and channel capacity in the case of not increase the system bandwidth and system power requirements, by a great attention.MIMO technology and the combination of OFDM technology MIMO-OFDM solution, has great potential in improving the effectiveness and reliability for the wireless link, is one B3G system solutions; OFDM technology and CDMA technology constitute the MC-CDMA solution, because of its excellent performance is also considered one of the most competitive programs in B3G system,.Scheduling algorithm of wireless systems main realizes the radio resource allocation combines the characteristics of wireless links, and has an important influence on the performance of the entire system. Scheduling algorithm research for the future wireless communications system is an important aspect in wireless resource management study. At present, using utility function and cross-layer theory to achieve performance optimization are gradually being the concerned by researchers.Therefore, the paper main study scheduling algorithm of MIMO-OFDM system and MIMO MC-CDMA systems and then do some simulation analysis, the work includes the following aspects.First of all, in a single cellular MIMO-OFDM downlink framework, simulate performance of RR, QPF and MCI scheduling algorithms. Through the simulation, analysis throughput performance, throughput fairness performance, service opportunities fairness performance, packet delay and the number of antennas affection on the algorithm performance, then present the simulation curves.Secondly, in a single cellular MIMO-OFDM downlink framework, combined with the utility function thought, design and implementation of utility function based scheduling algorithm UBS (Utility Based Scheduling), and algorithm performance were compared with RR, QPF, MCI three classical scheduling algorithm, simulation analysis of the algorithm throughput performance, fairness performance, packet loss rate and packet delay performance and other aspects of the performance. The results show that the algorithm obtains a good performance, and has a certain practical value.Finally, the paper also combined with the concept of cross-layer design, designed and implemented theory of cross-layer based scheduling algorithm CBS (cross layer based scheduling) in MIMO MC-CDMA system downlink framework and the algorithm performance were compared with RR, QPF, MCI three algorithms. Through simulation, the algorithm throughput, packet loss rate, packet delay and fairness performance is analyzed. Simulation results show that the algorithm in throughput and packet loss rate performance achieved a high performance advantages.