Relationship between PAPR and the number of sub-carriers in a multi-carrier communication system

In multi-carrier systems ( for example OFDM) the number of sub-carriers generate a high PAPR ( peak to average power ratio) of the generated signal. This fact has ramifications on the design and implementation of the circuits following the modulation and information generating circuits. In addition this also limits the number of sub-carriers that can be used. For example it the RFPA has a limited 1 dB compression point then high PAPR signal would cause the RFPA to be backed off from its most efficient operating point i.e the 1 dB compression point leading to loss of efficiency and thereby high power dissipation and so on. A brief paper released by Signal Processing Group Inc addresses the question of estimating the number of carriers and their relationship to the PAPR. Please visit the SPG website and click on the complimentary items to access this paper.

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