Patent ID: 7924907

Claim:
A spreading apparatus using a child orthogonal variable spreading factor (OVSF) code pair, comprising: a channel condition information receiving means for receiving and analyzing channel condition information including a channel condition metric wherein the channel condition metric is analyzed using equation: Channel_condition ⁢ _metric ⁢ ( l , k , n ) = ⁢ E [ Re ⁡ [ P r l ⁡ [ k + n ] ⁢ P r l ⁡ [ k ] * ] P r l ⁡ [ k ] ⁢ P r l ⁡ [ k ] * ] , wherein P r l [k] denotes a k th receiving CPICH pilot symbol at an l th finger, P r l [k]=α l (k)e jφ l (k) P t [k] denotes P r l [k] with phase distortion and attenuation, and P t [k] denotes a k th pilot symbol, P r l [k+n]=α l (k+n)e jφ l (k+n) P t [k] denotes a (k+n) th received CPICH symbol at a l th finger, and Re[P r l [k+n]P r l [k]*]=α l (k+n)α l (k)cos(φ l (k+n))−(k)) denotes a real value of an inter symbol correlation that is a coherence time measuring metric, P r l [k]P r l [k]*=α l (k) 2 , and E[x] denotes an expectation value of x; a switch controlling means for receiving the channel condition metric from the channel condition information receiving means and transferring a data stream according to the received channel condition information; a first spreading means for receiving the data stream from the switch controlling means, and spreading the data stream using a single OVSF code; and a second spreading means for receiving the data stream from the switching controlling means, and spreading the data stream using a child OVSF code pair.