| The future wireless communication systems are expected to support a broad range of multimedia services to mobile users with guaranteed quality of service (QoS). With the increasing demands for wireless services, the available frequency bandwidth of the systems is very limited and should be used efficiently. In arranging transmission over the shared radio channel, the design of an efficient medium access control (MAC) protocol is of great importance. In this thesis, we study the issues related to QoS provisioning in a multimedia wideband code division multiple access (CDMA) system. Solutions to resource allocation and channel access problems are proposed so that the system can efficiently support multimedia traffic.; Based on the time-division duplex (TDD) and time division multiple access (TDMA), we establish a hybrid TD/CDMA system model. A centralized MAC protocol is proposed. Packet scheduling and power allocation are performed by the base station. To guarantee the QoS requirements, we propose a fair packet loss sharing (FPLS) algorithm. The QoS requirements of all users can be satisfied simultaneously and the system resources can be used efficiently. To implement the FPLS algorithm, we first formulate an optimization problem. Since the optimization problem cannot be solved in real time, a realistic packet scheduling scheme is proposed. In multi-cell environment, the FPLS algorithm is combined with a received power limited (RPL) algorithm. The RPL algorithm minimizes the received power for each packet. With known path loss, it in turn minimizes the transmitted power as well. The intercell interference caused by the scheduled packet is also limited by the scheduling to increase the system capacity. Simulations with various traffic classes are perform to demonstrate the efficiency of the proposed algorithms. |
