Reducing the crest factor of CDMA downlink signal by adding unused channelization codes

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 paper 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 ideal case, no error is introduced at the receiver.