8 Signalling parameters

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

8.1 Downlink signalling parameters

8.1.1 UE identification

This identifies the UE (or UEs) for which data is transmitted in the corresponding HS-DSCH TTI. The UE identity is implicitly carried on the HS-SCCH through inclusion in the CRC calculation.

8.1.2 Transport Block Sizes

This defines what transport block size is used in the corresponding HS-DSCH TTI. The signalled parameter is an index to a pre-defined set of available transport block sizes. Note that for MIMO, there can be two transport block sizes in a TTI and for combined dual cell HSDPA with MIMO, there can be up to four transport block sizes in a TTI. For MIMO mode with four transmit antennas the second and the third transport block sizes are same for three stream transmission and for four stream transmission, the size of first and fourth transport blocks is identical for four stream transmission [4].

8.1.3 Channelisation codes (FDD only)

This identifies to the UE (or UEs) the codes it (they) should receive and decode.

8.1.4 HS-PDSCH configuration (TDD only)

This identifies to a UE the timeslots and codes it should receive and decode. Additionally, which transport formats are applied on HS-DSCH is also signalled. An identical set of channelisation codes is used in each of the identified timeslots.

8.1.5 HARQ information

Details of signalling parameters for the HARQ Protocol can be found in subclause 7.1.2. In addition, to support the Incremental Redundancy combining scheme, the Redundancy version is also signalled on the HS-SCCH.

8.1.6 Measurement feedback rate (FDD only)

This identifies the feedback rate for downlink quality measurement. This information may be sent at a much lower rate than the other parameters described in this subclause.

8.1.7 HS-PDSCH power offset

Default power offset between HS-DSCH code channel and P-CPICH (or S-CPICH in case beamforming with S-CPICH is used).

8.1.8 Void

8.1.9 Void

8.1.10 HS-SCCH Cyclic Sequence Number (HCSN) (TDD only)

A cyclic counter that is incremented each time a HS-SCCH transmission is sent to a given UE. Separate counters are maintained for each UE. The counter is used by the UE to estimate the BLER on the HS-SCCH for the purposes of closed loop power control.

In 1.28Mcps TDD, in HS-DSCH transmission in CELL_FACH and CELL_PCH state as defined in subclause 16 and 17, UE without a dedicated H-RNTI in CELL_FACH state and UE in CELL_PCH state ignores the value of HCSN.

8.2 Uplink signalling parameters

8.2.1 ACK/NACK

A one-bit indication per stream is used by the HARQ protocol to indicate a successful/unsuccessful transmission on the HS-DSCH for single and dual stream transmisions. For three stream transmission one bit indication is used to indicate a successful/unsuccessful transmission for the first transport block, while one bit indication is used to indicate a successful/unsuccessful transmission of second and third transport blocks. Note that the bit indicates a successful transmission of both the transport blocks when both second and third transport blocks are successfully decoded individually. For four stream transmission, one bit indication is used to indicate a successful/unsuccessful transmission of first and fourth transport blocks. Note that the bit indicates a successful transmission of both the transport blocks when both second and third transport blocks are successfully decoded individually. While one bit indication is used to indicate a successful/unsuccessful transmission of second and third transport blocks. Note that the bit indicates a successful transmission of both the transport blocks when both second and third transport blocks are successfully decoded individually.

In FDD in HS-DSCH reception in CELL_FACH state is as defined in clause 14, the ACK/NACK feedback is provided only if the UE is transmitting on a common E-DCH resource, is transmitting DTCH/DCCH traffic, has successfully resolved collision, and has been so configured by the network. Otherwise ACK/NACK feedback is not provided.

In 1.28Mcps TDD in HS-DSCH reception in CELL_FACH state as defined in clause 16, the ACK/NACK feedback is provided only when UE has a dedicated H-RNTI.

8.2.2 Measurement report

Measurement feedback information contains channel quality indicator that may be used to select transport format and resource by HS-DSCH serving Node-B. For FDD, the transmission rate of the measurement report to the network is configured by higher layer signalling. For TDD, when operating in CELL_DCH state, when operating in CELL_DCH state, a measurement report is associated with each HS-SCCH transmission.

In FDD in HS-DSCH reception in CELL_FACH state as defined in clause 14, the measurement result on RACH can be used for link adaptation as defined in subclause 14.2. Other measurement feedback information, such as CQI, can be sent if the UE is transmitting on a common E-DCH resource, is transmitting DTCH/DCCH has successfully resolved collision, and has been so configured by the network. The transmission rate of this other measurement feedback information is configured by higher layer signalling.

In 1.28Mcps TDD in HS-DSCH reception in CELL_FACH state as defined in clause 16, the measurement result on RACH can be used for initial link adaptation as defined in subclause 16.2. When UE is allocated a dedicated H-RNTI, a measurement report is associated with each HS-SCCH transmission.