ing to the quantized wideband correlation matrix can be requested by the BS for operation with transform codebook-based feedback mode using the Feedback Polling A-MAP IE. The BS may request the Table 10-21 Downlink MIMO Modes outside Open-loop MIMO Region Mini-Band Sub-Band based CRU based CRU Permutation Permutation Support Support MIMO Encoding Permutation (Diversity (Localized Index Description Format Precoding Support Allocation) Allocation) Mode 0 Open-Loop SU-MIMO adaptive Mode 1 Open-Loop SU-MIMO Vertical encoding Yes (Ns =2)) Yes (2 < Ns < 4) (spatial multiplexing) adaptive Mode 2 Closed-Loop Vertical encoding Adaptive Yes (Ns < 4) SU-MIMO (spatial multiplexing) 602.500 Mode 3 Open-Loop MU-MIMO Horizontal (spatial multiplexing) encoding adaptive Mode 4 Closed-Loop MU- Horizontal Adaptive MIMO (spatial encoding downfish multiplexing) Mode 5 Open-Loop SU-MIMO Conjugate data (transmit diversity) repetition adaptive screenes CHAPTER 10 The IEEE 802.1 16m Physical Layer (Part II) Table 10-22 Downlink MIMO Parameters Number of Transmit Spatial Rate Number of Number of Number of Mode Index Antennas (Nt) per Layer (R) Streams (Ns) Sub-carriers Layers (L) MIMO Mode 0 MIMO Mode 1 and MIMO Mode 2 MIMO Mode 3 and MIMO Mode 4 MIMO Mode 4 2 and 1 2 and 1 2 and 1 2 and 1 MIMO Mode 5 Two streams to one MS and one stream to another MS, each with a single layer. Two streams to one MS and one stream to each of other two mobile stations, each with a single layer. 10.5 IEEE 802. 16m downlink MIMO schemes Table 10-23 Different Types of Open-loop Region and Associated Parameters [2] Type of Open-loop Number of Supported MIMO Region Streams MIMO Mode Permutation Type 0 MIMO Mode 0 MIMO Mode 1 (Ns=2) Type 1 MIMO Mode 5 (Ns=1) Mini-band based CRU (diversity allocation) Sub-band based CRU (localized allocation) Type 2 MIMO Mode 1 (Ns = 2) Sub-band based CRU MIMO Mode 3 (Ns = 2) (localized allocation) Table 10-24 Downlink MIMO Modes inside Open-loop MIMO Region [2] Mini-Band based CRU Sub-Band based CRU DRU Permutation Permutation S