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In this paper, we propose a novel low complexity Partial Transmit Sequence (PTS) technique employing Random phase sequence matrix (RPSM) for peak to average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems. The main goal of our suggested scheme is to achieve the optimum phase sequence matrix to minimize PAPR and simultaneously reduce the computational complexity by decreasing the number of Inverse Fast Fourier Transform (IFFT) operations required. Lower PAPR reduces the complexity of Digital to Analog converters (DAC) and increases the efficiency of power amplifiers. Analytical expressions for Complementary Cumulative Distribution Function (CCDF), Number of subcarriers, subblocks and Total computational complexity are derived. Simulation results match closely with the analytical results. It is demonstrated that a favorable tradeoff can be achieved between the reduction of PAPR and computational complexity. It is observed that the suggested modified PTS technique outperforms the traditional PTS (T-PTS) technique.

Abstract Selected mapping (SLM) algorithm has been widely used for reducing high peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signal. One of the factors affecting SLM performance is high computational complexity. To overcome this effect, in this paper, the time domain signals available at the output of IFFT blocks are separated into real odd, real even, imaginary odd and imaginary even subsequences using Fourier transform properties. To generate more candidates, the subsequences corresponding to each time-domain signals are swapped to get M4 candidates from M IFFT operation as swapped SLM. Then the real subsequences are retained and the imaginary subsequences are transformed into time reversed, circularly shifted and time-reversal of circularly shifted subsequences. Therefore, the proposed scheme generates 4M4 candidates by combining different real subsequences and imaginary subsequences using only M IFFT operations. The simulation results illustrate that the proposed SLM scheme offers an improved PAPR reduction performance than other existing algorithms. Also, the proposed algorithm achieves 97% computational complexity reduction in terms of multiplications and 67% in terms of additions when compared to CSLM. Similarly, it provides 75% complexity reduction in terms of multiplications and 20% in terms additions when compared to swapped SLM. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel low complexity Partial Transmit Sequence (PTS) technique employing Random phase sequence matrix (RPSM) for peak to average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems. The main goal of our suggested scheme is to achieve the optimum phase sequence matrix to minimize PAPR and simultaneously reduce the computational complexity by decreasing the number of Inverse Fast Fourier Transform (IFFT) operations required. Lower PAPR reduces the complexity of Digital to Analog converters (DAC) and increases the efficiency of power amplifiers. Analytical expressions for Complementary Cumulative Distribution Function (CCDF), Number of subcarriers, subblocks and Total computational complexity are derived. Simulation results match closely with the analytical results. It is demonstrated that a favorable tradeoff can be achieved between the reduction of PAPR and computational complexity. It is observed that the suggested modified PTS technique outperforms the traditional PTS (T-PTS) technique. [ABSTRACT FROM AUTHOR]

Selected mapping (SLM) technique is commonly employed for reducing peak to average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. Conventional SLM scheme has better spectral efficiency, but requires a bank of inverse fast Fourier transforms (IFFTs) to produce candidate signals, resulting in a dramatic increase in computational complexity. To reduce the computational complexity of the SLM technique, this paper proposes a new PAPR reduction scheme of OFDM system, called a modified fast T-transform based SLM OFDM scheme, which considerably reduces the computational complexity with better PAPR reduction performance compared to the conventional T-SLM OFDM scheme. The proposed scheme is analytically and numerically evaluated for the OFDM system specified in the IEEE 802.16d standard. For the OFDM system with 256 subcarriers, the proposed scheme can reduce the complex multiplications by 68.7 % with the lower PAPR by range of 7 dB which is about 1 dB less than the conventional SLM based OFDM. [ABSTRACT FROM AUTHOR]