The supplemental channels are used to transmit the data signals.
Also, the real-valued PN spreading operations were changed to complex multiplications to better
make use of nonlinear PAs.
CDMA200 supports multirate users through the usage of various modulation schemes, multiple
code channels, and FEC techniques. These are best described through the multiple radio configurations
available on the reverse TCH. We list some characteristics in Table 1.4.
In the table below, we have a column named number of carriers; the CDMA2000 air interface
specification calls this spreading rate. The PN chip rate for spreading rate 1 is 1.2288 Mcps, while for
a spreading rate of 3, the chip rate is 3.6864 Mcps. With this in mind, the reverse fundamental channel
and supplemental channel structures were actually shown in Fig. 1.14 for the radio configuration
numbers 1 and 2.
Ablock diagram of the RL physical channel multiplexing and QPSK spreading is shown in Fig. 1.15.
This corresponds to radio configurations 3 and 4 for the reverse TCH and using spreading rate 1.
For radio configurations 5 and 6, the RL channel multiplexing and spreading block diagram is
similar to the one shown in Fig. 1.15. The exception being using spreading rate 3, which translates
to a chip rate of 3.
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