Rake receiver

Rake receiver is the digital section of a CDMA receiver which permits the phone (or cell) to separate out the relevant signal from all the other signals. The relevant signal will be encoded with a known Walsh Code and a known phase of the Short code, and the rake receiver can do this because the Walsh codes are orthogonal and the Short code is orthogonal to itself at different offsets. The rake receiver is capable of receiving multiple signal sources and adding them together using multiple fingers, each of which has the ability to use a separate phase of the short code and long code and a separate Walsh code if necessary. Different fingers might track multiple signals from the same cell (arriving at slightly different times due to multipath) or might track separate cells due to soft handoff.