Research On Wireless Packet Scheduling For Single-Carrier And Multi-Carrier Systems

Wireless packet scheduling manages services in wireless networks, schedules the transmission duration and determines the transmission rate. It plays a key role in QoS provisiong. In modern wireless networks, new service types are constantly emerging, and physical layer tranmission techniques (both single-carrier and multi-carrier) are constantly evolving, all these raise new challenges to wireless packet scheduling techniques.This thesis focuses on wireless packet scheduling for single-carrier and multi-carrier systems. Several new wirelss packet scheduling algorithms are proposed for Best-Effort (BE) services and Non-Real-Ttime (NRT) services.For BE services in single-carrier systems, we proposed an Asymptotic Throughput Maximization Algorithm (ATMA). This algorithm employs a new utility function which is asymptotic to linear function. It can solve the large throughput loss problem in the traditional proportional fair scheduling, without violating the 3GPP2 fairness criteria.For NRT services in single-carrier systems, we propoosed an S-Utility Optimization (S-UO) algorithm, which employs a utility function in the form of multiplication of S-function and logarithm function. It gives the utility function a proper definition and a slope near the minimum rate constraint point.For BE services in multi-carrier systems, we proposed a Modified Multi-Carrier Proportional Fairness (Modified-MC-PF) scheduling algorithm. This algorithm performs a full-search to find the maximum ratio of each user's maximum supportable rate to his currently achieved rate. It can increase the system utitlity and system throughput.For NRT services in multi-carrier systems, we proposed a Multi-Carrier Proportional Fairness with Minimum/Maximum Rate constraints (MC-PFMR) scheduling algorithm. This algorithm introduces the concept of minimum/maximum rate constraints on single sub-carrier and assigns each user a token counter. The token couter is the key mechanism to guarantee rate constraints and the ratio of sub-carrier channel gain to user's achieved rate is employed to guarantee proportional fairness. Simulation results show that this algorithm outperforms other existing algorithms in terms of maximum allowable number of users, system utility and system throughput. Besides, it is compatible with traditional proportional fair scheduling without rate constraints.For NRT services in multi-carrier systems, we also proposed a Multi-Carrier Maximum Throughput with Minimum/Maximum Rate constraints (MC-MTMR) scheduling algorithm. The token couter is the key mechanism to guarantee rate constraints and the sub-carrier channel gain is used to guarantee maximum throughput. Simulation results verify the effectiveness of the algorithm.