Reducing the crest factor of a CDMA downlink signal by adding unused channelization codes
Olli Väänänen, Jouko Vankka, Timo J. Viero, Kari A. I. Halonen · IEEE Communications Letters · 2002
In a CDMA system the downlink signal typically has a high peak-to-average ratio (crest factor). This sets strict requirements for the linearity of the power amplifier, which leads to poor efficiency and high costs. This letter discusses a method for reducing the crest factor based on the addition of a signal which is orthogonal to all the active channel codes. Therefore, in an ideal case, no error is introduced at the receiver.