12.1 General procedure

25.2143GPPPhysical layer procedures (FDD)Release 17TS

The UE uses the CPICH to separately estimate the channels seen from each antenna. One of the antennas will transmit the Antenna 1 modulation pattern of the P-CPICH as defined in subclause of [1]. The other antennas will transmit the Antenna 1 modulation pattern of a S-CPICH. If D-CPICHs are activated, the Antenna 3 and Antenna 4 will transmit the Antenna 1 modulation pattern of a D-CPICH within TTIs in which the HS-PDSCH is scheduled for a UE configured for MIMO mode with 4 transmit antennas. If D-CPICHs are activated, in addition to P-CPICH and S-CPICHs, the UE uses the D-CPICHs as additional phase references on antenna 3 and antenna 4 to estimate the channels for the HS-PDSCH demodulation. The Pilot configuration in support of MIMO mode with four transmit antennas operation of HS-DSCH in the cell is signalled by higher layers.

The UE determines number of transport block preferred a preferred precoding matrix and signals it to the Node B. The signalled information about the number of transport block preferred (NTBP) also called rank information (RI), preferred precoding matrix is termed precoding control indication (PCI) and is defined in subclause 6A.4.2. The PCI is signalled to the Node B together with channel quality indication (CQI) and number of transport block preferred (NTBP) as a composite NTBP/ PCI/CQI report according to the procedure defined in subclause 6A.1.2.3. The UE transmits the composite NTBP/PCI/CQI report to the Node B using the CQI field on the HS-DPCCH as defined in [1]. Based on the composite NTBP/PCI/CQI reports, the Node B scheduler decides whether to schedule one, two, three or four transport blocks in a cell to a UE in one TTI and what transport block size(s) and modulation scheme(s) to use for each of them.

The Node B signals to the UE the transport blocks scheduled, the precoding weights applied on the HS-PDSCH sub-frame using the precoding weight indication bits of part 1 of the corresponding HS-SCCH sub-frame. The precoding weight adjustment of each HS-PDSCH is done at the HS-PDSCH sub-frame border. For an UE with dual stream capability the Node B should not schedule more than two transport blocks.