Effective Simulations for PAPR Reduction using RCF with Hard Clipping, Smooth and Dynamic Clipping for QPSK Modulation

In this research paper, a variation of clipping ,RCF and tone reservation/injection techniques are examined with proper analysis of clipping ratio (CR) and depth factor(Alpha) in fine tuning of a PAPR reducing system. By exploiting the sparsity of clipping events in the time domain relative to predefined clipping threshold and generate the OFDM bins of the incoming broadband channel into narrow band channel. The concept of OFDM is to send the large amount of digital data in parallel using high speed modems which satisfies the mathematical definition of orthogonality for complex exponential functions over the interval [0, TOFDM] resulting in spectral efficient with flexible bandwidth allocation but not power efficient technique. This makes the OFDM for its robustness against the multipath fading channels. With the theme of power efficient drawback the gateway has open for the PAPR analysis in OFDM with different techniques in research for the power amplifier at the receiver in battery back off. In amplifier with nonlinear characteristics will cause undesired distortion of the in-band and out-of-band signals. The distortion-based techniques reduce the PAPR of the OFDM symbol with the price of adding distortion to the signal points in the subcarriers. Direct clipping simply suppresses the time-domain OFDM signals of which the signal powers exceed a certain threshold. The penalty is the significant increase of out-of-band energy. Peak windowing or filtering after direct clipping can be used to reduce the out-ofband energy. After the filtering operation, the peak of the time-domain signal may re-grow. Hence, recursive clipping and filtering (RCF) can be used to suppress both the out-of-band energy and the PAPR. RCF can be modified by restricting the region of distortion to obtain improved error performance. On the other hand, estimation of the clipping noise at the receiver can be used to improve the error performance of direct clipping, smooth clipping or RCF. The redundancy-based technique includes coding, selective mapping (SLM), partial transmit sequences (PTS), tone reservation (TR) and tone injection (TI) etc. The results has been analysis with CCDF calculations for N=128,256 with effective variation of CR{=0.4,0.6,0.8,1, 1.2,1.4,1.6,1.8,2}, depth factor(alpha=0.1,0.2,0.3,0.4,0.5,1,5,10,15) with clipping and RCF analysis with additional signal power ,mean power, peak power for classical clipping, smooth clipping and dynamic clipping for certain no of iterations. For better data rate communication we did the simulations of the tone reservation and tone injection with effective PAPR analysis.