In Reply to: Question about CDMA (IS-95) posted by Borja Perez on 03/06/01 at 5:30 AM:
The Walsh codes are applied before QPSK modulation.
I can recommend two books for you. One is:
CDMA RF System Engineering, by Samuel C. Yang, published by Arctech House. (www.artechhouse.com) Sam is very knowledgeable and a genuinely nice guy. I worked with him at AirTouch.
The second is:
Handbook of CDMA System Design, Engineering, And Optimization, edited by Kyoung Il Kim, published by Prentice Hall. You can get it at Fatbrain.com
Hope that helps!