ysical processing and structure of primary and secondary fast-feedback channels [2] (i.e., CQI report delay). Therefore, the reported CQI in frame n which might have been measured on a reference signal at frame n - 1 or earlier is associated with an appropriate MCS index for frame n. In order to allocate an appropriate MCS level and rank to an MS based on its actual conditions, the BS would make further adjustments in the MS reports by taking into consideration the CQI delay and the mobility conditions. For MU-MIMO feedback modes with codebook-based feedback, the CQI is calculated assuming that the interfering users are scheduled by the serving BS using rank-1 precoders, which are mutually orthogonal and orthogonal to the rank-1 precoder associated with the reported The parameters contained in the PFBCH and SFBCH are encoded as follows: The STC rate is encoded with 1, 2, or 3 bits when the BS utilizes 2, 4, or 8 transmit antennas, respectively. The sub-band CQI and sub-band average CQI are encoded with 4 bits corresponding to the nominal MCS of Table 10-18. The differential CQI is encoded with 2 bits indicating MCS index increment/ CHAPTER 10 The IEEE 802. 16m Physical Layer (Part II) Table 10-16 Primary Fast-Feedback Channel Parameters [2] Feedback Parameter Mode (MFM) Usage Channel Quality 0,1,2,3,4,5,6,7 Wideband CQI or sub-band CQI for the best sub-band Indicator (CQI) Space Time Coding 0,1,2,3 (STC) Rate Indicator Sub-band Index 2,3,5,6 Sub-band selection for the best sub-band Precoding Matrix Index 3,4,6,7 Wideband PMI or sub-band PMI for the best sub-band (PMI) Event-driven Indicator to The MS requests switching MIMO feedback mode between Request MFM distributed and localized allocations. Switching Event-driven Indicator The MS requests uplink bandwidth (resources for uplink for Bandwidth Request traffic). Indicator Event-driven Indicator 0,1,4,7 The MS informs the serving BS about the frequency partition for Frequency Partition index. Selection (FPS) Event-driven Indicator This parameter is an indication 