12 MIMO operation of HS-DSCH with four transmit antennas

25.2143GPPPhysical layer procedures (FDD)Release 17TS

This section applies only when a UE is configured in MIMO mode with four transmit antennas.

The general transmitter structure to support MIMO operation of HS-PDSCH transmission with four transmit antennas is shown in Figure 11. For each transport block channel coding, interleaving, spreading and scrambling are done as in non-MIMO mode. Symbol level interleaving between symbols modulated from the primary and the fourth transport blocks is applied. Similarly, symbol level interleaving between symbols modulated from the second and the third transport block. The detailed operation for symbol level interleaving is descried in subclause 12.2. The Node B scheduler can decide to transmit one or two or three or four transport blocks to a UE in one TTI in the serving HS-DSCH cell. The spread complex valued signals are fed to all TX antenna branches, and weighted with precoding weights w_mn, where m = 0,1,2,3, and n = 0 to number of transport blocks decided. The precoding weights w_mn is the m^th row and n^th column of the precoding matrix defined in Table 14B.7 of [2]. The Node B can dynamically schedule the UE with one or two or three or four transport blocks.

Figure 11: The generic downlink transmitter structure to support MIMO mode with four transmit antennas operation for HS-PDSCH transmission.