Peak to Average Power Ratio Analysis of Multi-carrier and Multi-standard Signals in Software Radio Context

High peak to average power ratio (PAPR) is a main area of concern in multi-carrier signals like orthogonal frequency division multiplexing (OFDM) modulated signals and substantial work has already been done on OFDM PAPR problem. Very little work has yet been done on software radio (SWR) signal´s PAPR problem. The fact that SWR system is a combination of different standards, where each standard consists of multi-carrier signals makes SWR signal extremely power fluctuating and causes high PAPR. PAPR analysis of multi-carrier (MC)-GMSK, MC-QPSK and OFDM is carried out which are the modulation techniques for GSM, UMTS and WLAN standards respectively. It is revealed that each standard´s signal follows Central limit theorem and thus has Gaussian distribution. SWR signal is then formed using these standards which also has Gaussian distribution. This result is important as it proves OFDM to be a special case of SWR system regarding PAPR issue as they both share the same PAPR distribution. And thus making already developed OFDM PAPR reduction techniques applicable to SWR signals.