13b MU-MIMO operation in HSDPA channel in 1.28Mcps TDD

25.3083GPPHigh Speed Downlink Packet Access (HSDPA)Overall descriptionRelease 17Stage 2TS

In 1.28Mcps TDD, MU-MIMO operation in HSDPA channel includes the following contents.

– Four midamble allocation patterns (pattern 1A, pattern 1B, pattern 2A, pattern 2B) for the special default midamble allocation scheme as in [9] shall be used for MU-MIMO operation. For the UEs sharing the same downlink physical resource in the same TTI, the different midamble allocation patterns shall be allocated to them.

– A MU-MIMO capable UE can be signalled to operate in "MU-MIMO mode" by RRC.

– MU-MIMO can be applied in CELL_DCH and CELL_FACH.

– If UE is configured in MU-MIMO mode and the default midamble allocation scheme is signalled to UE by RRC, the default or special default midamble allocation scheme can be used. Whether the default or special default midamble allocation scheme is used is signalled to UE dynamically through HS-SCCH in [11].

– When UE is configured in MU-MIMO mode, HS-SCCH type 4 or type 8 is used to inform the UE of the HS-DSCH related control information.

– In CELL_DCH and CELL_FACH, the Node B scheduler decides whether to allocate the same downlink physical resource to multiple UEs in the same TTI based on the spatial isolation between the wireless channels of these UEs.

– In CELL_DCH, standalone midamble channel can be used to improve the uplink channel estimation, thus improving the wireless channel spatial isolation decision performance.