Reducing the peak to average power ratio of multicarrier signals by adaptive subcarrier selection

Abstract

The non-constant envelope is a fundamental problem of the OFDM multicarrier technique. In many cases, nonlinear power amplifiers with power saturation lead to a high out-of-band radiation. Another characteristic of OFDM is the influence of frequency selective fading of mobile radio channels. To overcome this effect coding schemes are required for low error rates, therefore a certain redundancy has to be introduced. This paper presents a combination of an adaptive subcarrier selection as a coding scheme with a new algorithm to reduce the out-of-band radiation, exploiting the non-information carrying subcarriers. The efficiency of this technique is demonstrated by the simulation results.