(Forward link - From base station to mobile station)

Following are the forward link features of CDMA 2000:

1) It supports chip rates of 1.2288 Mcps (where N = 1) and for multicarrier it is N*1.2288 Mcps (N=3, 6, 9, 12).

2) It Uses Transmit Diversity reduce the required Eb/N0 (required transmit power per Channel) and thus enhance the system capacity.

3) It uses Orthogonal Modulation To reduce or eliminate intracell interference, each forward link physical channel is modulated by a Walsh code.

4) It uses Frame lengths of

• 20-ms frames are used for signaling and user information
• 5-ms frames are used for control information

5) It provides Synchronous forward link

6) It provides Forward error correction (FEC) :

• Convolutional codes (k =9) are used for voice and data
• Turbo codes (k = 4) are used for high data rates on SCHs

7) Common physical channels (CPHCH) used by CDMA 2000 for forward link are

• Dedicated Auxiliary Pilot (F-DAPICH) channel
• Common Assignment (F-CACH) channel
• Pilot (F-PICH) channel
• Sync (F-SYNC) channel
• Fundamental (F-FCH) channel
• Supplementary (F-SCH) channel
• Broadcast (F-BCH) channel
• Common Power Control (F-CPCCH) channel
• Transmit Diversity Pilot (F-TDPICH) channel
• Auxiliary Transmit Diversity Pilot channel
• Dedicated Control (F-DCCH) channel