Dynamic crest factor reduction system

Abstract

A system and method for performing digital crest factor reduction. In one embodiment, the method is devised to suppress the signal amplitude to maintain a low signal peak to average ratio (PAR), while maintaining a desirable Error Vector Magnitude (EVM). This technique may be designed to operate in highly dynamic signal conditions.

What is claimed is: 
     
         1 . A crest reduction system for gain leveling, the system comprising:
 an estimator for estimating a root-mean-square (RMS) level of a first signal carrier and an RMS level of a second signal carrier, each of the first and second signal carriers having an amplitude;   a leveling setter for receiving the estimated RMS levels of the first and second signal carriers, for producing a first gain leveling factor and a second gain leveling factor for the first signal carrier by using the estimated RMS level of the first signal carrier, and for producing a third gain leveling factor and a fourth gain leveling factor for the second signal carrier by using the estimated RMS level of the second signal carrier;   a first leveler for receiving the first signal carrier and the first gain leveling factor and for changing the amplitude of the first signal carrier by adjusting the first signal carrier according to the first gain leveling factor;   a second leveler for receiving the second signal carrier and the third gain leveling factor and for changing the amplitude of the second signal carrier by adjusting the second signal carrier according to the third gain leveling factor; and   a filter configurator for receiving the second and fourth gain leveling factors, for producing one or more first filter coefficients to further change the amplitude of the first signal carrier according to the second gain leveling factor, and for producing one or more second filter coefficients to further change the amplitude of the second signal carrier according to the fourth gain leveling factor,   wherein the second gain leveling factor is substantially equal to the reciprocal of the first gain leveling factor, and   wherein the fourth gain leveling factor is substantially equal to the reciprocal of the third gain leveling factor.