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Peak power reduction of OFDM signals with sign adjustment

Publication ,  Journal Article
Sharif, M; Tarokh, V; Hassibi, B
Published in: IEEE Transactions on Communications
August 12, 2009

It has recently been shown that significant reduction in the peak to mean envelope power (PMEPR) can be obtained by altering the sign of each subcarrier in a multicarrier system with n subcarriers. However, finding the best sign not only requires a search over 2n possible signs but also may lead to a substantial rate loss for small size constellations. In this paper, we first propose a greedy algorithm to choose the signs based on p-norm minimization and prove that the resulting PMEPR is guaranteed to be less than c log n where c is a constant independent of n for any n. This approach has lower complexity in each iteration compared to the derandomization approach of [1] while achieving similar PMEPR reduction. We further improve the performance of the proposed algorithm by enlarging the search space using pruning. Simulation results show that PMEPR of a multicarrier signal with 128 subcarriers can be reduced to within 1.6 dB of the PMEPR of a single carrier system. In the second part of the paper, we address the rate loss by proposing a block coding scheme in which only one sign vector is chosen for K different modulating vectors. The sign vector can be computed using the greedy algorithm in n iterations. We show that the multi-symbol encoding approach can reduce the rate loss by a factor of K while achieving the PMEPR of c logKn, i.e., only logarithmic growth in K. Simulation results show that the rate loss can be made smaller than %10 at the cost of only 1db increase in the resulting PMEPR for a system with 128 subcarriers. © 2009 IEEE.

Duke Scholars

Published In

IEEE Transactions on Communications

DOI

ISSN

0090-6778

Publication Date

August 12, 2009

Volume

57

Issue

7

Start / End Page

2160 / 2166

Related Subject Headings

  • 4606 Distributed computing and systems software
  • 4009 Electronics, sensors and digital hardware
  • 4006 Communications engineering
  • 1005 Communications Technologies
  • 0906 Electrical and Electronic Engineering
  • 0804 Data Format
 

Citation

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Sharif, M., Tarokh, V., & Hassibi, B. (2009). Peak power reduction of OFDM signals with sign adjustment. IEEE Transactions on Communications, 57(7), 2160–2166. https://doi.org/10.1109/TCOMM.2009.07.080012
Sharif, M., V. Tarokh, and B. Hassibi. “Peak power reduction of OFDM signals with sign adjustment.” IEEE Transactions on Communications 57, no. 7 (August 12, 2009): 2160–66. https://doi.org/10.1109/TCOMM.2009.07.080012.
Sharif M, Tarokh V, Hassibi B. Peak power reduction of OFDM signals with sign adjustment. IEEE Transactions on Communications. 2009 Aug 12;57(7):2160–6.
Sharif, M., et al. “Peak power reduction of OFDM signals with sign adjustment.” IEEE Transactions on Communications, vol. 57, no. 7, Aug. 2009, pp. 2160–66. Scopus, doi:10.1109/TCOMM.2009.07.080012.
Sharif M, Tarokh V, Hassibi B. Peak power reduction of OFDM signals with sign adjustment. IEEE Transactions on Communications. 2009 Aug 12;57(7):2160–2166.

Published In

IEEE Transactions on Communications

DOI

ISSN

0090-6778

Publication Date

August 12, 2009

Volume

57

Issue

7

Start / End Page

2160 / 2166

Related Subject Headings

  • 4606 Distributed computing and systems software
  • 4009 Electronics, sensors and digital hardware
  • 4006 Communications engineering
  • 1005 Communications Technologies
  • 0906 Electrical and Electronic Engineering
  • 0804 Data Format