2. HSDPA Channels
• For HSDPA, four new channels are defined
• The Data payload is carried on a transport channel called the High
Speed Downlink Shared Channel (HS-DSCH), which operates on a
fixed TTI of 2 ms.
• At the Physical Layer, the HS-DSCH is mapped onto the High Speed
Physical Downlink Shared Channel (HS-PDSCH)
• This common channel (HS-PDSCH), which is capable of multi-code
transmission, is shared among users by employing a combination
of time and code division multiplexing.
3. HSDPA Channels
• Scheduling and control information relating to each HS-PDSCH
transmission is communicated to a UE on one of several possible High
Speed Shared Control Channels (HS-SCCH)
• During each 2 ms TTI, a single HS-SCCH carries control information for
one UE. Therefore, the number of necessary HS-SCCH channels is
defined by the number of UEs that will have concurrent HS-PDSCH
transmissions
• On the UL, Release 5 introduces a new Physical Layer channel called the
High Speed Dedicated Physical Control Channel (HS-DPCCH).
• Each UE operating in HSDPA mode has a single HS-DPCCH, which carries
a positive or negative acknowledgment (ACK/NAK) of a transmitted HSDSCH data transmission and also the CQI report that informs the Node B
scheduler of the
