use-1 and 3 reuse-3), Low power transmission in other reuse-3 partitions Downlink Control Medium Access Compressed Medium Individual (user-specific) MAP, separately-coded, once per Channels Protocol Access Protocol/ subframe, Frequency Division Multiplexed with data Sub- Medium Access Protocol, jointly-coded, once per frame, Time Division Multiplexed with data Broadcast Channel Frame Control Primary and Secondary Superframe Headers Header/Downlink Channel Descriptor/ Uplink Channel Descriptor Synchronization Full bandwidth, 114 Primary preamble in 5 MHz bandwidth once per superframe Channel codes, once per Secondary preamble in full bandwidth, 768 codes, 2 times per frame superframe Midamble Not Supported Full bandwidth, once per frame, used for PMI/CQI feedback Uplink Control Channel Quality and 4-bit/6-bit CQI Primary and Secondary Fast Feedback Channel for CQI/PMI Channels Precoding Matrix feedback Feedbacks Bandwidth Request Reuse of initial 3 uplink 6 X 6 tiles, regular (5-step) and fast (3-step) contention- ranging structure and based access sequence; 5-step access Sounding One OFDM symbol in One OFDM symbol in the uplink subframe, CDM and FDM for the uplink subframe, mobile station and antenna multiplexing CDM and FDM for mobile station multiplexing Introduction 802.16m surpasses that of the legacy system, resulting in extended capabilities to support a variety of existing and future services and applications with high quality and capacity. Table 2 compares the throughput of the two systems under selected test scenarios that were specified in the IMT-Advanced evaluation methodology document. In Table 2, a TDD system with 10 MHz bandwidth and frequency reuse 1, as well as a DL:UL ratio of 29:18 was assumed for both systems. The legacy system employs a 4 X 2 single-user MIMO configuration and sounding-based beamforming in the downlink, along with a 1 X 4 collaborative MIMO in the uplink. The IEEE 802.16m uses a 4 X 2 multi-user MIMO in the downlink in addition to a 2 X 4 collaborative MIMO in the uplink with