共查询到20条相似文献,搜索用时 46 毫秒
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In this paper, we propose and evaluate a novel nonlinear companding transform (NCT) scheme for peak-to-average power ratio (PAPR) reduction in orthogonal frequency division multiplexing (OFDM) systems. The key idea of the proposed scheme is to transform the original Gaussian-distributed OFDM signals into a specific statistics form, whose target probability density function is defined by a piecewise function with an inflexion point. By properly choosing the transform parameters, this scheme can enable more flexibility and freedom in the companding form so that a favorable tradeoff between PAPR reduction and bit error rate (BER) performance can be achieved. Moreover, compared to existing NCT techniques, this scheme dramatically decreases the impact of companding distortion on the BER performance to reach a given PAPR level. The analytical expressions regarding the achievable transform gain in PAPR, complementary cumulative density function, attenuation coefficient, and selection criteria of transform parameters are derived. Simulation results justify the significance and accuracy of the analytical expressions presented. 相似文献
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一种降低OFDM系统PAPR的改进压扩方法 总被引:1,自引:1,他引:0
正交频分复用(OFDM)技术是一种多载波调制方式。作为第四代移动通信系统的核心技术,OFDM己成为当今高速无线通信领域的研究热点。正交频分复用(OFDM)系统存在高峰值平均功率比(PAPR)问题,这一问题会导致系统性能降低,为其实用化设置了障碍。文中研究了一种改进的降低PAPR的非线性压缩与扩展算法,可以得到更好的PAPR性能。该方法的特点在于采用一种计算复杂度较低的非线性压扩函数,同时融合了叠加训练序列方法的改进非线性压扩算法,从而有效地降低系统PAPR。理论研究和仿真结果表明,与传统方法相比,所提出的改进压缩与扩展方法可以在降低系统复杂度的同时得到更好的PAPR性能。 相似文献
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Linear Companding Transform for the Reduction of Peak-to-Average Power Ratio of OFDM Signals 总被引:1,自引:0,他引:1
《Broadcasting, IEEE Transactions on》2009,55(1):155-160
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针对传统压扩变换方法存在计算复杂度较高或设计灵活性不够的问题,推导并提出了一种新的、更为高效的非线性压扩变换改进算法。通过引入适当的参数,简化了压扩变换中功率守恒时的参数计算问题,所提出的方法不仅可以降低计算复杂度,而且系统灵活性也得到进一步的改善。仿真实验表明该算法可在抑制PAPR和保证误码性能之间取得更好的折中。 相似文献
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Wireless Personal Communications - As a result of the rapid progress in editing techniques, fakes and forgeries in images became easy and pervasive. Image forgery detection methods have been... 相似文献
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降低信号的峰均功率比(PAPR)是正交频分复用(OFDM)技术的一个关键问题。μ律压扩法作为降低PAPR的一个重要方法,其非线性的特点难于在硬件上实现。在传统的μ律压扩方法基础上,介绍了一种分段线性压扩方法,并对其效果进行仿真评估,并提出一种新的硬件实现方法,在降低复杂度上有良好的效果。 相似文献
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Ibraheem Zeyid T. Ahmed Kawakib K. Fazea Yousef Madi Mohammed Mohammed Fathey Ali Abdulrazzaq Qasem 《Wireless Personal Communications》2022,124(1):423-436
Wireless Personal Communications - This paper proposes an enhanced PAPR reduction technique which combines an enhanced PTS method with Mu-Law companding. The enhanced PTS method improves... 相似文献
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OFDM技术的应用越来越广泛,但是其发送信号功率的峰均功率比(PAPR)比较大是其主要的缺陷之一。本文提出了一个降低OFDM信号PAPR的有效灵活的技术。该方法是通过恰当的选择OFDM调制中各个子载波的时域脉冲波形。仿真结果表明该方法能够大大降低OFDM信号的PAPR值。该技术与现有的其他方法相比实现复杂度也更低。 相似文献
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A peak-to-average power ratio (PAPR) reduction scheme with low complexity is proposed for the multicarrier spread spectrum
(MC-SS) system in personal area network (PAN). Traditional clipping and filtering scheme requires a high oversampling rate
to meet the emission mask requirements. This would cause high power consumption for mobile PAN devices in personal network.
To solve the problem, upsampling is introduced between clipping and filtering in this paper to reduce the oversampling rate.
A simplified implementation structure is also derived for the proposed scheme. Simulation results show that its complexity
is about 65% of the conventional scheme while achieving satisfying performance.
相似文献
Lu RongEmail: |
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正交频分复用(OFDM)技术的一个缺点是信号的高峰值平均功率比(PAPR)大大降低了系统中线性功放的效率。本文提出一种新的基于Nyquist脉冲成形的PAPR抑制方法。这种方法基于选择适当的Nyquist脉冲波形集合对OFDM的各个子载波进行脉冲成形。分析论证了该方法的PAPR上限值和所用的脉冲成形波形集合。仿真结果表明该方法能有效降低任意子载波数目的OFDM信号的PAPR值,而且与已有方法相比应用更为简单。因此脉冲成形技术不仅能对传输信号进行频谱成形来提高系统的频带利用率,而且还可以减小信号的PAPR值。 相似文献
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The 3rd generation partnership project long term evolution standard uses orthogonal frequency division multiplexing access in downlink and single carrier frequency division multiple access (SCFDMA) scheme for the uplink transmissions, which utilizes single carrier modulation and frequency domain equalization. In this paper, we proposed a Raised Cosine-like companding scheme to reduce the peak-to-average power ratio (PAPR) of SCFDMA signals. The proposed scheme can transform the original SCFDMA signals into Raised Cosine-like-distributed. Moreover, this scheme can compress the large signals, while maintaining the average power constant. Computer simulation results show that the proposed companding scheme can offer better PAPR reduction by properly choosing the parameters. 相似文献
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《Broadcasting, IEEE Transactions on》2009,55(3):679-685
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Wireless Personal Communications - The offset quadrature amplitude modulation (OQAM) with filter bank multicarrier (FBMC) has turn on considerable interest in last decades over orthogonal frequency... 相似文献
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Byung Moo Lee Rui J. P. de Figueiredo Youngok Kim 《Wireless Personal Communications》2012,62(2):431-442
The high peak-to-average power ratio (PAPR) of time domain signals has been a major problem in orthogonal frequency division
multiplexing (OFDM) systems, and thus various PAPR reduction algorithms have been introduced. Partial transmit sequence (PTS)
is one of the most attractive solutions because of its good performance without distortion. However, it is considered as an
impractical solution for the realization of high-speed data transmission systems due to its high computational complexity.
In this paper, a novel PAPR reduction algorithm based on a tree-structured searching technique is proposed to reduce the PAPR
with low complexity. In the proposed scheme, the computational complexity of searching process is decreased by adjusting the
size of tree with two parameters, width and depth, while preserving good performance. The simulation results show that proposed
scheme provides similar performance with optimum case with remarkably reduced computational complexity. 相似文献
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Discrete Cosine Transform based Single carrier frequency division multiple access (DCT-SCFDMA) is a prominent technique for providing high data rates in multimedia services. It also provides high Quality of Service to the users by mitigating the fading of signals. But High peak-to-average power ratio (PAPR) is a technical challenge which reduces the efficiency of RF power amplifiers. In this article, a novel joint scheme of PAPR reduction method is proposed and analyzed based on pulse shaping and absolute exponential companding (AEXP) technique. Our method proposes the use of standard raised cosine filter and square root raised cosine filter along with the AEXP companding process separately in DCT-SCFDMA system for different subcarrier mapping techniques e.g. interleaved frequency division multiple access and localized frequency division multiple access. Through extensive simulations, the numerical analysis presents that proposed architecture achieves significant improvements over the existing standard pulse shaping methods when used alone in DCT-SCFDMA system as far as the lowest PAPR is concerned. 相似文献