Affiliations: Department of Telecommunication Engineering, Xidian University, Xi’an, Shannxi, China
Correspondence:
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Corresponding author. Zheng Xiang, Department of Telecommunication Engineering, Xidian University, Xi’an, Shannxi, 710071, China. E-mail: [email protected].
Abstract: In this paper, a novel signal candidate generation method and a new joint coding and probability peak to average power ratio (PAPR) reduction scheme are proposed for a Luby transform (LT) coded orthogonal frequency division multiplexing (OFDM) system. When a few LT packets are mapped into an OFDM symbol, all subcarriers are automatically divided into several blocks. We permutate these packets and assign them different subcarrier blocks to generate different signal candidates instead of multiplying by many phase rotation vectors and using active constellation extension, and the transmitted symbol will be the one whose PAPR is the smallest. Moreover, through introducing one phase rotation vector, the proposed algorithm is modified, and the PAPR reduction performance is enhanced. Simulation results prove that our proposed scheme can not only fully explore the spatial freedom brought by the mapping relationship between LT packets and OFDM symbols but also can obtain effective PAPR reduction performance. Since the permutation operation does not change the degree value of each packet, the new scheme can still maintain good decoding performance.
