The HS-SCCH is also required for proper demodulation of the HS-DSCH channels. STTD is used
for the HS-SCCH physical channels. Since more transmit and receive antennas are intended to be
used then the assumption of independent fading across all antennas should be revisited to include
more realism in the antenna modeling.
504 CHAPTER NINE
DSCH
Transmiter
DSCH
Transmiter
Primary
Data
X
w1(k)
w1(k)
w2(k)
w2(k)
w3(k)
w3(k)
w4(k)
w4(k)
Tx Antenna #1
X
+
+
Secondary
Data X
X Tx Antenna #2
Antenna Weight
Calculation
From UE
Other Channels
Other Channels
FIGURE 9.24 UMTS 2 2 MIMO example for the NodeB transmitter.
Receiver complexity and channel models are also other issues deserving special attention. Much
work has been done on creating Spatial Channel Models (SCM) that would more accurately model
the wireless communication channel. The SCM contains parameters such as angle of arrival (AOA),
angle of departure (AOD), angular spread (AS) which are in addition to the already discussed parameters
of path loss, delay spread, shadowing, Doppler spread, and so on.
For example, the AS with respect to the NodeB is discussed next. The antenna pattern, A() is provided
below assuming a three-sector deployment.
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