18 Forward link traffic channel for spreading rate 1.
FIGURE 1.19 Forward link traffic channel for spreading rate 3.
the amount of bits per frame exceeds a certain threshold value. All convolutional codes have a constraint
length of 9. The octal representations of the generator functions are given below.
Code rate G0 G1 G2 G3 G4 G5
R 1/2 753 561
R 1/3 557 663 711
R 1/4 765 671 513 473
R 1/5 457 755 551 637 625 727
The turbo encoders have a common coder whose outputs are punctured according to a specific pattern,
to achieve the desired code rates of 1/2, 1/3, 1/4, and 1/5. The reader is encouraged to consult [18]
for further details.
1.2.4 Wideband CDMA
In this section, we will present the physical layer details of the 3G cellular system called wideband
CDMA (WCDMA). This system uses FDD for uplink and downlink communications [19??“23].
We will begin our discussion of WCDMA by reviewing the uplink. In the uplink, the data channel
and control channel are quadrature multiplexed. By this, we mean that the dedicated physical data
channel (DPDCH) is transmitted on the I-axis and the dedicated physical control channel (DPCCH)
is transmitted on the Q-axis. The uplink time-slot structure is given in Fig.
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