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.