. . . . . Sub #0 Sub #4
10 msec
2560 Chips 5120 Chips
The SF is constant at 256. HS-DPCCH can only exist together with an uplink DPCCH. The 3GPP
standard provides details on mapping the downlink signal quality to uplink signaling, through the use
of certain lookup tables. The HS-DPCCH time slot timing relationship with respect to the uplink
DPCH time slot is not necessarily time aligned. This depends on the downlink timing offset given to
the DPCH.
The uplink spreading and scrambling block diagram is shown in Fig. 7.113. The HS-DPCCH can
be added in either the I- channel or the Q-channel, depending on the number of DPDCH channels.
The exact conditions are clearly stated within the 3GPP standard.
7.7.2 Multicode Overview
The HS-PDSCH uses an SF 16. Subtracting a code reserved for the common channels leaves us
with 15 possible codes that can be transmitted by the NodeB. Depending on the UE capabilities as
well as the channel conditions; this value varies. Hence multicodes are viewed as resources and are
illustrated in Fig. 7.114.
In Fig. 7.114, we show K 1 parallel data streams being spread with K 1 consecutive channelization
codes, followed by a single scrambling operation. The K 1 data streams can be transmitted
to either a single or multiple UE.
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