TABLE OF CONTENTS The Dedicated forward link Physical Channel (DPCH) carries data generated at link layer (layer 2) of the DPDCH time multiplexed with control information of the DPCCH generated at physical layer (layer 1). The forward DPCH frame is shown in Figure 8.106. Each frame is 10 ms length and made up of 15 slots. Each slot has a length of 2560 chips. The data size is variable given by 10 2 k bits where k= 0, , 7 so the minimum size of the data is 10 bits and the maximum is 1280 bits. The spreading factor is 
giving a minimum spreading factor of 4 and a maximum of 512.
The exact number of bits of different fields (Pilot, Data 1, Data 2, TFCI and TPC) is tabulated in the standards and these numbers depend on bit rate and services being carried by the channel.
The function of the Common Pilot Channel (CPICH) is to aid the mobile terminal in channel estimation. The CPICH is an unmodulated code channel scrambled with the cell specific primary scrambling code. UTRAN has two types of CPICH, namely the primary and the secondary. The primary type uses the primary scrambling code with a pre-defined channelization code sequence. Each cell/sector has only one primary and secondary CPICH broadcast over the entire cell/sector. The secondary channel...
