Artificial signals addition for reducing PAPR of OFDM systems
Résumé
One of the major drawbacks of OFDM modulation is the large envelope fluctuations which either result in an inefficient use of high power amplifiers (HPA) or decreased transmission system performance. Peak-to-Average Power Ratio (PAPR) is a very well known measure of the envelope fluctuations and has become the cost function used to evaluate and design OFDM systems. In this paper, we propose a PAPR reduction scheme known as adding signal method for which the principle is to reduce the PAPR of the OFDM signals by adding several artificial signals. It is an extension of the method that we have proposed in [1]. The major advantages of this technique include downward compatibility, no performance degradation and no transmission of side information. A method is said to be downward compatibility if its implementation in a transmitter does not imply modifications in the associated receiver. According to simulation results, the method outperforms the PAPRreduction performance presented in [1]. For example, at 10−2 of the Complementary Cumulative Distribution Function (CCDF), the PAPR is reduced about 3.5 dB for 5 artificial signals addition, whereas this reduction is about 1.5 dB for method [1] which is the case of one artificial signal addition.