| An FDD wideband CDMA MAC protocol, a wideband TD-CDMA MAC protocol, and an OFDM-TDMA/SA MAC protocol are proposed, respectively, for macro-cellular networks, micro-cellular networks, and broadband wireless LANs. For both the FDD wideband CDMA MAC protocol and wideband TD-CDMA MAC protocol, a minimum-power allocation algorithm is derived to maximize the system capacity and guarantee heterogeneous BER requirements of multimedia traffic. To fairly serve multimedia traffic with different QoS constraints when the system capacity varies with interference, a wideband CDMA GPS-scheduling scheme is derived for the FDD wideband CDMA MAC on the basis of the minimum-power allocation algorithm. For the wideband TD-CDMA MAC protocol, a joint rate- and BER-scheduling scheme for multimedia traffic is proposed. The joint scheduling scheme enhances QoS of multimedia traffic and enables the system to reach the maximum capacity. Based on the minimum-power allocation algorithm, an effective-bandwidth based CAC algorithm is also derived for both the FDD wideband CDMA and wideband TD-CDMA MAC protocols. In the MAC protocol for the OFDM-based broadband wireless LAN, a new multiple access scheme called OFDM-TDMA/SA is first proposed. Then an optimum subcarrier bit-allocation algorithm is derived considering the frequency-selective fading environment. Based on the OFDM-TDMA/SA frame structure and the optimum subcarrier bit-allocation algorithm, a hierarchical scheduling scheme is proposed to serve multimedia traffic. The MAC protocol implementation on a software radio system is also investigated. |
