共查询到17条相似文献,搜索用时 218 毫秒
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正交频分复用系统较高的峰均比大大限制了其在宽带电力线通信中的应用.为取得合适的峰均比,文章提出一种低复杂度的改进算法,将分组预判决与压扩技术相结合来降低峰均比的值,并给出了系统的实现方法,在建立的电力线信道模型基础上,对其进行了仿真.仿真结果表明,该算法能够改善信号的峰均比,减小误码率且计算复杂度低,有效地提高了电力线... 相似文献
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一种用于TETRA多载波系统的功放线性化方法 总被引:2,自引:0,他引:2
针对TETRA数字集群多载波通信系统对功放线性度要求高的问题,提出了峰值因子削减与数字预失真联合处理的功放线性化方法。采用峰值加窗的峰值因子削减方法在保证调制精度及带外辐射抑制指标要求前提下,能够降低多载波发射信号的峰均比,从而提高功放的线性工作点。宽带多载波发射系统中功放非线性体现出记忆性,提出了适用于TETRA系统的基于查找表的记忆型预失真器,有效地扩大功放的线性工作范围。通过仿真实验可以证明,峰值加窗方法与记忆型预失真器联合用于TETRA多载波系统中,能够将功放工作范围扩展到非线性区域,同时工作点提升了1.5dB,显著地提高了功放的工作效率。 相似文献
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针对基于偏移正交幅度调制的滤波器组多载波系统峰均功率比较高的情况,将DFT扩频技术加以改进应用到FBMC/OQAM中,提出了一种移除DFT矩阵中输入基脉冲的剪枝DFT扩频(Pruned-DFTs)技术。该技术通过移除DFT矩阵中基脉冲,来实现将发送端较少子载波上的符号映射到较多子载波上传输,进而来减少子载波之间的重叠,降低系统PAPR,使系统具有优良峰均比性能。该技术充分利用了DFT扩频的单载波效应,解决了多载波系统普遍存在的峰均比较差的问题。最后的仿真结果证明,本方案可实现与SC-FDMA相媲美的峰均比性能,并可有效降低系统BER,而且该技术可使系统传输信号在时间上的重叠大大减小,使平均传输功率显示出几乎完美的矩形形状,但计算复杂度仅略微提高2倍。 相似文献
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为了提高电力线载波通信的可靠性和有效性,提出一种在发送设备端进行的信号处理方法,即相位调整预编码方法。利用了发送多个载波信号相位改变的不同,可以改变多个载波信号叠加功率和,从而减少电力线载波通信的峰均比。分析了峰均比形成的原因,提出了以最小化发送功率为目标函数,求解每个载波发送相位的优化问题。仿真结果表明,该预编码方法能够有效抑制电力线载波通信中过高的峰均比问题,在不增加复杂度的前提下,有效提高了通信的可靠性,证明了该方法的正确性和有效性。 相似文献
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基于四阶累积量的滑动峰态算法在表征微弱信号的非高斯特性方面具有优势,可用于对微弱放电信号进行检测。但在混合噪声干扰下,受固定滑动窗宽度的影响,该算法对微弱放电信号的检测性能会显著劣化。针对该问题,提出了基于小波分解和滑动峰态相结合的联合检测方法,并进行了仿真分析和实验验证,结果表明:利用小波变换对信号的多尺度分解以及信号在不同分解尺度上的特征差异,该联合检测方法实现了信号在多个优化的滑动窗宽度共同作用下的峰态检测,进一步增强了其抗噪声干扰能力,对微弱放电信号的检测性能相比原有滑动峰态算法有明显提升。 相似文献
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减少OFDM信号峰均功率比的PTS方法研究 总被引:1,自引:0,他引:1
正交频分复用(OFDM)作为一种高速信息传输的技术,具有很好的抗多径干扰能力,但它的一个主要缺点是有很高的峰均功率比(PAPR),现在已有许多解决方案用来降低OFDM信号的峰均功率比。部分传输序列(PTS)的方法可以改善OFDM符号的峰均功率比的性能,它是一种很有效的方法。文章对PTS的方法进行描述,在传统的PTS方法基础上进行改进,提出了一种减小复杂度的方法。 相似文献
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OFDM(Orthogonal Frequency Division Multiplexing),中文含义为正交频分复用,它是一种多载波调制技术.由于具有良好的抗多径性能,适用于高速的数据传输,OFDM成为近年来人们研究的热点.但是,由于它存在峰平功率比(PAPR)较高的问题,限制了它在实际系统中的应用.本文从概率问题出发,提出了序列预处理的方法,它不在于降低信号幅度的最大值,而是降低信息序列中峰值出现的概率.经过仿真证明序列预处理的方法有良好的效果. 相似文献
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针对传统选择性映射(SLM)降低正交频分复用(OFDM)系统峰均比(PAPR)方法存在计算复杂度高、需传输边带信息降低了有效数据的传输速率等缺点,文中提出了一种无需传送边带信息的改进SLM方法,具有频带利用率高、复杂度低的优点。该方法首先将四进制数据进行环形映射,经串并转换和数据分割后,再经相位因子旋转,将原来的一个星座点映射到环形圆上的互不重合的多个点上。快速傅里叶逆变换(IFFT)后,对其中一个子块进行循环移位,并与另一个子块重新组合,可以产生更多的候选信号,选PAPR最小的进行传输,进一步降低了高PAPR出现的概率。仿真表明,改进的方法能更有效地降低电力线OFDM系统的PAPR和误符号率。 相似文献
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When measuring multicarrier communication systems such as an orthogonal frequency division multiplexing (OFDM) or UWB wireless signal, there is a problem that the effective measuring dynamic range of the measuring instrument may be reduced, since the peak‐to‐average power ratio (PAPR) of the measured signal is significantly high. In order to solve this problem, we propose a technique that maintains the measuring dynamic range by dividing the measured signal into multiple bandwidths to decrease the measured signal power. We made a prototype of the measuring equipment, confirmed the operation of the algorithm, and verified the effectiveness of dynamic range improvement is 5 to 8 dB in relation to a conventional circuit. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(2): 28–35, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22367 相似文献
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Power consumption is a vital issue for communication systems, especially for those which powered by batteries. In wireless com-munication system, the power consumption of PA (power amplifier) consumes a large portion of power compared with another component. How to reduce the power consumption of PA is always one of the big topics in the R&D and application of PA. Modern communication systems which have the high Peak to Average Power Ratio (PAPR). Envelope tracking technology can effectively reduce the power consumption of PA, especially for the high PAPR system. In the meantime, ET does not affect the performance of PA and communication system. This paper introduces the principle of ET, and gives the test method of ET performance. An ET test system has been built using R&S SMW 200A vector signal generator and FSW vector signal analyzer. The measurement result shows 20% of power saving by the application of ET. 相似文献
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The authors have proposed the signal decomposition technique as one of the powerful solution to mitigate the large peak‐to‐average power ratio (PAPR) to be addressed in orthogonal frequency division multiplexing (OFDM) transmitters especially on mobile terminals. In order to enhance the receiver SNR, the simple noise elimination techniques working together with the signal decomposition technique have also been proposed that eliminates the noise added on the decomposed constant amplitude on‐off‐signals taking advantage of the knowledge of their constant amplitude at the receiver. In this paper, we discuss the parameter design issue of the proposed techniques and their optimization. Then, demonstrate the PAPR, the power‐added efficiency (PAE), and also the BER performances operating on the optimized parameters. It is confirmed that the proposed signal decomposition technique improves the PAPR by 4 dB and doubles the PAE at the complementary cumulative distribution function of 1%. It is also confirmed that the proposed noise elimination technique improves the receiver SNR by 3 dB at the BER of 10 to 3, which is nearly equal to that of conventional OFDM, under the conditions that the decomposed signals are transmitted over the independent additive white Gaussian noise channels. Furthermore, it is demonstrated that the proposed techniques work properly when the decomposed signals are transmitted over 2 × 2 multi‐input multi‐output. 相似文献
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OFDM系统的峰均功率比过高的问题大大影响了它的实用性,本文给出了基于SLM法降低峰均功率比的方法,通过计算机仿真得到了不同分数阶数α下的累积分布函数曲线.结果表明,当α取最优值时系统的峰均比互补累积函数性能优于基于FFT的系统性能. 相似文献