Need of scrambling code

[Shivanand.kadwadkar]

I have some confusion about the scrambling code

1. As far i know scrambling code is used to mix(re-arrange) the the data is it different from turbo/convolution code that we use.
2. When scrambling code is assigned ( Is there any other scrambling code other that what we search in cell search procedure)
3. How UE get the uplink and downlink scrambling code

Thanks for all you reply