Traditional Partial Transmit Sequence Research Articles

A novel reduced complexity optimized PTS technique for PAPR reduction in wireless OFDM systems

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.

A Novel Subblock Linear Combination Scheme for Peak-to-Average Power Ratio Reduction in OFDM Systems

In this paper, we propose a novel subblock linear combination (SLC), which is based on the cyclic projections algorithm, scheme to reduce the PAPR of OFDM signals. Moreover, an improved SLC method with a relaxation factor, named as the R-SLC scheme, is also proposed to accelerate the convergence rate of the SLC scheme in this paper. The key idea of the two novel methods is to divide an OFDM block into several subblocks, and iteratively generate the linear combination of these subblocks with low PAPR. Compared with the traditional partial transmit sequence (PTS) scheme, the coefficients of the linear combination with the proposed schemes are obtained by iterative calculation with the cyclic projections algorithm, instead of by exhaustive searching and selecting in the preset discrete set. Therefore, one big advantage of the proposed schemes is that the computational complexity is much lower than that of the traditional PTS scheme. Theoretical analysis and simulation results show that the proposed schemes could offer good performances of the PAPR reduction and bit-error-rate with low computational complexity.