Patent ID: 6885653

Claim:
A channel allocation method in a CDMA (Code Division Multiple Access) communication system, comprising the steps of: receiving from a UTRAN (UMTS (Universal Mobile Terrestrial System) Terrestrial Radio Access Network) one SF (Spreading Factor) node C SF,k out of 2 m− 1 SF nodes (where m is an integer larger than 3) arranged in the form of a tree having a mother node and child nodes; searching a group including the received SF node C SF,k in accordance with For ⁢ ⁢ SF ≤ 2 m - 1 4 , ( P 1 · SF , P 1 · k ) = ( 2 m - 1 4 , n ) For ⁢ ⁢ SF > 2 m - 1 4 , ( P 2 · 2 m - 1 4 , P 2 · n ) = ( SF , k ) where , P 1 = 2 m - 1 4 · SF ⁢ ⁢ and ⁢ ⁢ P 2 = 4 · SF 2 m - 1 ; spreading a signal on a dedicated physical data channel (DPDCH) with an OVSF (Orthogonal Variable Spreading Factor) code corresponding to a selected one of the received SF node and its child nodes in the searched group; and spreading a signal on a dedicated physical control channel (DPCCH) with an OVSF code corresponding to an SF node determined by F ⁡ ( C 2 m - 1 4 · k ) = C 2 m - 1 , 2 m - 1 - k - 1 ⁢ ⁢ ( k = 0 , 1 , … ⁢ ) if the n of the received SF node is the first half value having (2 m −1)/4 and F ⁡ ( C 2 m - 1 4 · k ) = C 2 m - 1 , 2 m - 1 - ( k - 32 ) ⁢ ⁢ ( k = 0 , 1 , … ⁢ ) if the n thereof is the latter half value halving the same.