The HS-SCCH will carry the downlink control signaling related to its associated HS-PDSCH
transmission. Let us make a quick comment about the timing relationship between P-CCPCH,
HS-DSCH, and HS-SCCH.
There are 5 subframes per single 10-msec radio frame. The P-CCPCH and HS-SCCH channels
are frame aligned. The HS-DSCH overlaps the HS-SCCH by a single time slot (see Fig. 7.111). This
FIGURE 7.111 HS-DSCH and HS-SCCH subframe timing relationship.
Sub #0
10-msec Radio Frame
Sub #1 Sub #2 Sub #3 Sub #4
Sub #0 Sub #1 Sub #2 Sub #3 Sub #4
P-CCPCH
HS-SCCH
HS-DSCH
allows the UE to use the first two slots of the HS-SCCH subframe to set up the HS-DSCH demodulator.
The one-slot overlap reduces the round-trip latency as well as memory requirements of the UE.
HS-DPCCH Channel. The HS-DPCCH carries uplink signaling related to the downlink HS-DSCH
transmission. This signaling consists of HARQ acknowledgment (HARQ-ACK) and Channel Quality
Indication (CQI). The ACK/NACK is carried in the first time slot while the CQI is carried in the second
and third time slots. The time slot and frame structure is given in Fig. 7.112.
3G WIDEBAND CDMA 431
FIGURE 7.112 HS-DPCCH subframe structure.
ACK/NACK CQI Control
Subframe
Sub #i .
Pages:
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706