可见光多维无载波幅度相位调制系统

发布时间：2018-05-13 20:24

本文选题：可见光通信 + 多维无载波幅度相位调制　；参考：《电子与信息学报》2017年12期

【摘要】：针对室内可见光通信调制技术和多用户接入问题,该文基于直流偏置和极性编码信号单极化思想提出两种系统复杂度低、频带利用率高的可见光多维无载波幅度相位(DCO-MCAP,U-MCAP)调制方案。首先利用最大最小优化算法构建无频谱泄漏的频域目标方程,采用完全重建(PR)条件作为非线性约束方程,求取时域正交的多维CAP滤波器组,然后分别采用"添加直流偏置"和"零值位置极性编码"实现信号单极性,以满足可见光通信"强度调制/直接检测"的要求。基于朗伯辐射模型,可见光背景噪声建模为加性高斯白噪声(AWGN),推导了DCOCAP/MCAP,U-CAP/MCAP 4种调制方案的误符号率理论解,仿真验证了其准确性。在5 m?5 m?3 m的室内场景下,仿真对比分析了2维、3维、4维可见光CAP调制系统的频带利用率、误码率等性能。结果表明,相同星座尺寸时,多维CAP调制的误码性能明显优于传统2维;相同频带利用率时,3种维度系统误码性能相近,可见光多维CAP调制为多用户接入提供可能性。此外,讨论了信道参数对可见光CAP系统的影响,发射机辐射角与收发信机之间距离都与信噪比损失呈现出正相关性。
[Abstract]:Aiming at the modulation technology of indoor visible light communication and the problem of multi-user access, this paper proposes two systems with low complexity based on DC bias and single polarization of polarity coded signals. DCO-MCAPU-MCAP) modulation scheme with high bandwidth efficiency. Firstly, the maximum and minimum optimization algorithm is used to construct the frequency-domain target equation without spectrum leakage, and the fully reconstructed PRA condition is used as the nonlinear constraint equation to obtain the multi-dimensional CAP filter banks with orthogonal time domain. Then "adding DC bias" and "zero-value position polarity coding" are used to realize the signal unipolarity, respectively, to meet the requirement of "intensity modulation / direct detection" in visible light communication. Based on the Lambert radiation model, the visible background noise is modeled as additive Gao Si white noise. The theoretical solutions of symbol error rate of four modulation schemes are derived, and the accuracy is verified by simulation. In the indoor scene of 5 m ~ 5 m ~ (m), the frequency band efficiency and bit error rate (BER) of the 2-D / 3D / 4-D visible light CAP modulation system are compared and analyzed. The results show that the BER performance of multi-dimensional CAP modulation is obviously better than that of traditional 2-D system with the same constellation size, and the BER performance of the three dimensional systems is similar at the same frequency band efficiency, and the multi-dimensional CAP modulation of visible light provides the possibility for multi-user access. In addition, the influence of channel parameters on visible CAP system is discussed. The distance between transmitter radiation angle and transceiver is positively correlated with SNR loss.
【作者单位】：大连海事大学信息科学技术学院;
【基金】：国家自然科学基金(61371091)~~
【分类号】：TN929.1

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