The Experts below are selected from a list of 307647 Experts worldwide ranked by ideXlab platform

A Antoniou - One of the best experts on this subject based on the ideXlab platform.

  • a new peak to average Power Ratio reduction algorithm for ofdm systems via constellation extension
    IEEE Transactions on Wireless Communications, 2007
    Co-Authors: Wusheng Lu, A Antoniou
    Abstract:

    Peak-to-Average Power-Ratio (PAPR) reduction for OFDM systems is investigated in a probabilistic framework. A new constellation extension technique is developed whereby the data for each subcarrier are represented either by points in the original constellation or by extended points. An optimal representation of the OFDM signal is achieved by using a de-randomization algorithm where the conditional probability involved is handled by using the Chernoff bound and the evaluation of the many hyperbolic cosine functions involved is replaced by a tight upper bound for these functions. The proposed algorithm can be used by itself or be combined with a selective rotation technique described in the paper and with other known algorithms such as the coordinate descent optimization and selective mapping algorithms to achieve further performance enhancements at the cost of a slight increase in the computational complexity. When compared with other existing PAPR-reduction algorithms, the enhanced algorithm offers improved PAPR-reduction performance and improved computational complexity although, the transmit Power is increased somewhat

  • peak to average Power Ratio reduction algorithms for ofdm systems via constellation extension
    International Symposium on Circuits and Systems, 2005
    Co-Authors: Y J Kou, A Antoniou
    Abstract:

    New Peak-to-Average Power-Ratio (PAPR) reduction algorithms for orthogonal frequency-division multiplexing (OFDM) systems are investigated in a probabilistic framework. Specifically, derandomization algorithms based on the Chernoff bound for PAPR reduction are developed by applying the so-called conditional probability method. Our simulations demonstrate that the proposed algorithms outperform several existing algorithms and the computational complexity of the proposed algorithms is found to be significantly less than that of existing algorithms.

  • New Peak-to-Average Power-Ratio reduction algorithms for OFDM systems using constellation extension
    PACRIM. 2005 IEEE Pacific Rim Conference on Communications Computers and signal Processing 2005., 2026
    Co-Authors: Y J Kou, A Antoniou
    Abstract:

    New Peak-to-Average Power-Ratio reduction (PAPR) algorithms for orthogonal frequency-division multiplexing systems are investigated in a probabilistic framework. Specifically, two de-randomization algorithms for PAPR reduction are developed by applying the so-called conditional probability method. Our simulations demonstrate that the proposed algorithms outperform several existing algorithms and the computational complexity of the proposed algorithms is found to be significantly less than that of existing algorithms.

L. Sanguinetti - One of the best experts on this subject based on the ideXlab platform.

  • On the Peak-to-Average Power Ratio of pre-equalized multi-carrier code-division multiple-access transmissions
    2005 IEEE 61st Vehicular Technology Conference, 2005
    Co-Authors: I. Cosovic, L. Sanguinetti
    Abstract:

    Recently, pre-equalization for multi-carrier code-division multiple-access (MC-CDMA) systems has attained increased interest. In addition, combined-equalization has been proposed to further enhance the error rate performance of conventional MC-CDMA systems. However, an important issue, Peak-to-Average Power Ratio (PAPR), has not been addressed within such systems in the literature. The purpose of this paper is to fill this gap. In particular, we focus on uplink MC-CD MA with pre- or combined-equalization and analyze its PAPR. A general expression for the PAPR of uplink MC-CDMA is derived and some analytical properties are provided. It turns out that PAPR significantly depends on applied pre-equalization technique. Thus, we show how pre-equalization coefficients could be designed in order to reduce PAPR.

Lajos Hanzo - One of the best experts on this subject based on the ideXlab platform.

  • peak to average Power Ratio reduction based on penalty cccp for filter bank multicarrier systems
    IEEE Transactions on Vehicular Technology, 2019
    Co-Authors: Fangyu Cui, Yunlong Cai, Minjian Zhao, Ming Lei, Lajos Hanzo
    Abstract:

    Filter bank multicarrier (FBMC) has received substantial research attention as benefit of its low out-of-band emission and high spectral efficiency. However, a main challenge of FBMC is its relatively high Peak-to-Average Power Ratio (PAPR). Hence we formulate an optimization problem for the PAPR reduction of FBMC signals, where the PAPR is minimized subject to the constraints of symbol distortion and dummy subcarrier Power used for PAPR-reduction. In order to tackle the highly coupled nonconvex problem, we convert the original problem into a more tractable yet equivalent form and then propose a novel algorithm based on the penalty concave-convex procedure (penalty-CCCP). Our simulation results show that the proposed algorithm substantially reduces the PAPR compared to conventional techniques.

Tao Jiang - One of the best experts on this subject based on the ideXlab platform.

  • peak to average Power Ratio reduction for ofdm oqam signals via alternative signal method
    IEEE Transactions on Vehicular Technology, 2014
    Co-Authors: Yang Zhou, Tao Jiang, Chuan Huang
    Abstract:

    In this paper, we consider the Peak-to-Average Power Ratio (PAPR) reduction problem for orthogonal frequency-division multiplexing with offset quadrature amplitude modulation (OFDM/OQAM). In particular, the OFDM/OQAM signal is generated by summing over M time-shifted OFDM/OQAM symbols, where successive symbols are interdependent with each other. The alternative-signal (AS) method, which directly leads to the independent AS (AS-I) and joint AS (AS-J) algorithms, is employed to reduce the PAPR of the OFDM/OQAM signal. The AS-I algorithm reduces the PAPR symbol by symbol with low complexity, whereas the AS-J algorithm applies optimal joint PAPR reduction among M OFDM/OQAM symbols with much higher complexity. To balance the performance and the computation complexity, we propose a sequential optimization procedure, which is denoted AS-S, which achieves a desired compromise between performance and complexity.

  • using fountain codes to control the peak to average Power Ratio of ofdm signals
    IEEE Transactions on Vehicular Technology, 2010
    Co-Authors: Tao Jiang
    Abstract:

    In this paper, we apply fountain codes to control the Peak-to-Average Power Ratio (PAPR) of orthogonal frequency-division multiplexing (OFDM) signals. The main key idea of the proposed scheme is based on the fact that the best fountain-coded OFDM packets can be generated with a low PAPR. Both theoretical analysis and simulation results prove that the proposed scheme can effectively obtain the desirable PAPR and good throughput with rateless codes. Moreover, the flexibility of controlling PAPR makes the proposed scheme more suitable for implementing random frame sizes and providing effective error detection.

  • reducing the peak to average Power Ratio using unitary matrix transformation
    Iet Communications, 2009
    Co-Authors: Xiaodong Zhu, Guangxi Zhu, Tao Jiang
    Abstract:

    A theoretical analysis is presented to show that in orthogonal frequency division multiplexing systems, the Peak-to-Average Power Ratio (PAPR) can be reduced by performing a unitary matrix transformation on the input vector of N symbols. The authors also prove that this transformation does not degrade the bit error rate (BER) or Power spectral density (PSD) performance. Based on this, the inverse discrete Fourier transform matrix is proposed as the unitary matrix to reduce the PAPR. The simulation results show that the proposed scheme can obtain significant PAPR reduction while maintaining good performance in the BER and the PSD. To further evaluate the performance of the proposed scheme, the authors compare it with some well known PAPR reduction techniques by simulations. It is demonstrated that the proposed scheme can offer better system performance and achieve a better compromise with regard to the PAPR reduction, BER, spectral efficiency and computational complexity.

  • an overview peak to average Power Ratio reduction techniques for ofdm signals
    IEEE Transactions on Broadcasting, 2008
    Co-Authors: Tao Jiang
    Abstract:

    One of the challenging issues for Orthogonal Frequency Division Multiplexing (OFDM) system is its high Peak-to-Average Power Ratio (PAPR). In this paper, we review and analysis different OFDM PAPR reduction techniques, based on computational complexity, bandwidth expansion, spectral spillage and performance. We also discuss some methods of PAPR reduction for multiuser OFDM broadband communication systems.

I. Cosovic - One of the best experts on this subject based on the ideXlab platform.

  • On the Peak-to-Average Power Ratio of pre-equalized multi-carrier code-division multiple-access transmissions
    2005 IEEE 61st Vehicular Technology Conference, 2005
    Co-Authors: I. Cosovic, L. Sanguinetti
    Abstract:

    Recently, pre-equalization for multi-carrier code-division multiple-access (MC-CDMA) systems has attained increased interest. In addition, combined-equalization has been proposed to further enhance the error rate performance of conventional MC-CDMA systems. However, an important issue, Peak-to-Average Power Ratio (PAPR), has not been addressed within such systems in the literature. The purpose of this paper is to fill this gap. In particular, we focus on uplink MC-CD MA with pre- or combined-equalization and analyze its PAPR. A general expression for the PAPR of uplink MC-CDMA is derived and some analytical properties are provided. It turns out that PAPR significantly depends on applied pre-equalization technique. Thus, we show how pre-equalization coefficients could be designed in order to reduce PAPR.