... codes to spread forwardphysical channels. For example, Walsh code 0 is assigned to the pilotchannel, code 32 to the sync channel, codes 1—7 to paging channels,and the rest to the forward traffic ... direction,they are used for orthogonal modulation where every six symbolsfrom the block interleaver output are modulated as one of 64 Walshcodes.Scrambling CodesPN codes form the basic building ... to the input. The underly-ing theory is well documented in the literature. See, for example, ref-erence [14] for a thorough description of shift register sequences.Reference [15] provides some...