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码间干扰直接影响可见光通信系统的通信性能,当前的应对方法存在一定的不足,为了实现系统信号稳定传输,文章采用基于小波变换的可见光通信系统码间干扰抑制技术,在分析可见光通信系统信道模型和信号多径特征基础上,利用小波变换将系统回波数据频谱变换到小波域,在小波域内通过恒虚警概率方法识别码间干扰小波系数,构建码间干扰小波系数的恒虚警检测器,将小波系数大于检测门限的码间干扰去除,实现对可见光通信系统码间干扰的抑制。实验结果表明,该方法的信号干扰抑制比和信号失真比均较低,可提高可见光通信系统的输出信噪比,有效抑制码间干扰对系统信号频谱的影响,保证系统信号传输稳定性。 相似文献
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本文分析了码间干扰(ISI)对相位分集频移键控(PD-FSK)光通信系统特性的影响,导出了由于ISI引起的系统功率代价的解析表达式,并考虑到典型的系统参数值,分析比较了功率代价与系统参数的关系。 相似文献
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张力军 《南京邮电学院学报(自然科学版)》1994,14(4):1-10
提出了一种改进的非线性符号间干扰的消除技术。在接收机中,采取“先消除后匹配均衡”的结构方案。非线性信道估计器采用一阶Volterra核测量及自适应递推算法。与Biglieri系统相比,性能可改善2-3dB.计算量和存储量减少到1/N(N为信道响应样值数)。在弥散非线性信道上进行9.6kb/s数据传输的模拟结果表明,我们提出的非线性消除技术可使16QAM系统的性能改善3-4个数量级。 相似文献
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室内可见光通信系统的传输信道易受到多径效应产生严重码间干扰,降低通信质量,为此提出了相位调制技术的可见光通信系统码间干扰识别方法.通过构建可见光通信系统信道模型,针对信道光源之间在时域和频域上形成的重叠光信号在多径效应作用下,产生的码间干扰,利用位调制技术对系统信道展开均衡设计,并依照多径扩展统计限定码元速率均值,实现... 相似文献
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为降低TD-SCDMA系统同频组网时同频邻区对终端信道估计造成的同频干扰,提出了一种时域的平行干扰消除算法,相对于串行干扰消除算法,在有多个强同频邻区干扰的条件下,表现出了更好的性能。 相似文献
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本文研究了基于变换域处理的OFDM系统信道估计的基本原理和变换域滤波处理方法,提出了一种变换域导频插值信道估计的改进迭代算法,同时,采用具有更好滤波效果的“带阻滤波器”优化了其中的变换域滤波器的设计,通过接收端检测到的信噪比调整能量参数。仿真结果表明,提出的采用优化变换域滤波器的信道估计算法具有较好的性能,在一定程度上可以接近于理想信道估计的性能。 相似文献
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针对传统信道估计中,导频容易受到噪声和干扰的污染,从而导致系统性能下降的问题,提出了一种适用于WiMAX系统的导频时频滤波方案.算法简单,易于实现.通过仿真结果证明在不同的信道模型下,此方案能明显地提高系统的性能. 相似文献
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Ahmet Rizaner Hasan Amca Kadri Hacolu Ali H. Ulusoy 《AEUE-International Journal of Electronics and Communications》2005,59(5):324-327
In this letter, we address the problem of mobile radio channel estimation at high channel efficiency using a small number of training symbols. A decision aided channel estimation scheme is proposed for slow fading multipath DS-CDMA channels. The approach is an extension of single-user least-square channel estimation. It is demonstrated that, due to the suggested channel estimate updating algorithm, the proposed scheme improves the channel estimation accuracy significantly. 相似文献
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Monte Carlo–based channel estimation and performance evaluation for UWOC links under geometric losses 下载免费PDF全文
Rabia Qadar Mumraiz K. Kasi Sara Ayub Faisal A. Kakar 《International Journal of Communication Systems》2018,31(6)
Underwater wireless optical communication has been studied and proposed as a potential technology for various underwater applications including monitoring and surveillance using wireless sensor networks. In this context, we present a statistical model using an exhaustive Monte Carlo approach for an underwater wireless optical communication link between sensor nodes in a data mulling environment. This work provides insights into the science of photon transport underwater, its utilization in a communication system, evaluation, and optimization of underwater communication. We characterize the temporal channel behavior taking into account multiple scattering of photons involving the constraints of detector aperture diameter, field‐of‐view (FOV), and link distance for an aligned point‐to‐point link. We analyze the designed model in terms of total received power and bit error rate for clear ocean waters. Our simulation results show that the detector aperture and FOV has an impact towards a successful communication in the distance from 5 to 20 m. In addition, results show that the FOV is an affecting factor only in the presence of larger aperture sizes of the detector. 相似文献
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A simplified parametric channel estimation approach was proposed for orthogonal frequency division multiplexing (OFDM) systems. Based on parametric channel model, this algorithm is composed of two parts: the estimation of channel parameters and channel interpolation. The exponentially embedded family (EEF) criterion is exploited to determine the number of channel paths as well as the multipath time delays. Consequently, the channel frequency responses is acquired via the estimated parameters. Additionally, the authors' scheme is computationally efficient owing to the needless of the eigenvalue decomposition or the estimation of signal parameters by the rotational invariance technique (ESPRIT). Simulations are provided to validate the performance of this algorithm from perspectives of the probability of correct estimation and the mean square error (MSE). It is demonstrated that this approach exhibits a superior performance over the existing algorithms. 相似文献