TABLE OF CONTENTS The reverse link is composed of access channels and reverse traffic channels sharing the same CDMA spectrum, which is 45 MHz lower than the frequency allocated to the forward link channels. The frequency band allocated to the forward link channels is 869 894 MHz and 824 849 MHz for the reverse link channels and carrier spacing 1.25 MHz. Each reverse traffic channel/access channel is identified by a distinct user long code. The logical channels over the reverse CDMA link are shown in Figure 8.24 which consists of n access channels and m traffic channels.
The reverse traffic channel is shown in Figure 8.25 for rate set 1 with peak data rate of 9600 b/s. Comparing the reverse traffic channel with the forward traffic channel shown in Figure 8.18, we can see many similarities between the two channels. But the differences are that the reverse traffic channel, unlike the forward, does not carry power control information, and the channelization is carried out by 64-ary orthogonal modulation by using a set of 64 Walsh functions.
The modulation by the 64-ary Walsh functions is achieved as follows: the interleaver output is partitioned into 6-symbol blocks used to select one of 64 orthogonal Walsh functions. If the 6-symbol block is converted into a decimal number k such that 0 ? k ? 63 then the Walsh function with index k is selected for...
