Analysis of PAPR in OFDM with CSS

Abstract

The present trends in wireless communication industry are in light of multi-carrier transmission technique for example, Orthogonal Frequency Division Multiplexing (OFDM) which is very encouraging as far as higher data rates and better resistance to frequency selective fading. Wireless communication standards like IEEE 802.11a/g/n/ac, IEEE 802.16e and numerous others utilize one or other variety of OFDM, for example, OFDMA and MIMO-OFDM. However, the immense drawback of the OFDM system is its high Peak to Average Power Ratio (PAPR). Every one of these utilizing the linear power amplier at the transmitter side so its operating point will go to the saturation point because of the high PAPR which prompts in-band distortion and out-of-band radiation. This problem can be avoided by increasing the dynamic range of the power of amplifier that leads to high consumption of power and cost at the base station. To battle the impact of high PAPR, a few PAPR reduction techniques have been contrived throughout the most recent couple of decades. Every one of these techniques need to strike a trade-off among a few parameters, for example, computational complexity, PAPR reduction performance, BER performance and others. Depending upon the requirement, the most proper technique is thus chosen. PTS system has been in presence since 1997 and gives an exceptionally successful PAPR reduction procedure with no restriction on the most extreme number of subcarriers. However the technique experiences an intense issue of high computational complexity. In this course a novel methodology which offers same PAPR diminishment and significantly reduces the complexity of the system by preserving the basic principle of the standard PTS technique is designed. The various quantities of IFFT blocks has been replaced by a single block to decrease the complexity of the framework. The proposed technique has been simulated and the PAPR reduction performance of the new technique has been compared with that of original PTS technique. Similarly, the complexities of the two techniques are compared based on the block diagrams. The proposed technique is applied to the multiple antenna system to reduce its PAPR. This system can increase the diversity to combat the deep fades that occurred due to frequency selective fading. This multiple antenna system has been simulated and the PAPR reduction of each antenna is analysed and compared with the standard PTS technique.