A subcarrier-phase control based PAPR reduction scheme without side-information transmission in LDPC coded OFDM systems

In this paper, a subcarrier-phase control based peak-to-average power (PAPR) reduction scheme without side-information transmission is proposed for LDPC coded OFDM systems. On the transmitter side, peak power of OFDM signal is reduced by multiplying the selected phase-sequence. On the receiver side, the phase sequence used for PAPR reduction is estimated without side information by utilizing the decoding property of LDPC code, i.e., based on the decoding information in single iteration sum-product calculation, limited number of candidate sequences is selected from all possible phase sequence patterns and the correct phase-sequence can be estimated by comparing the decoding results corresponding to these selected candidate sequences. Computer simulation results show that, when LDPC code with code-rate of R ¿ 1/2 is used, PAPR of OFDM signal can be reduced by about 2.4 dB without significant degradation in BLER performance as compared to perfect WF estimation in attenuated 12-path Rayleigh fading condition.