【摘要】：在能源日益緊缺、環(huán)境問題日益凸顯的今天,由于具有亮度高、能耗低、壽命長、性能穩(wěn)定等諸多優(yōu)點(diǎn),白光LED越來越廣泛地應(yīng)用于生活與商業(yè)照明。室內(nèi)可見光通信(Visible Light Communication,VLC)以白光LED為光源,既能提供很好的照明,又能實(shí)現(xiàn)穩(wěn)定可靠的數(shù)據(jù)通信。但是,LED調(diào)制帶寬低的特性限制了VLC的系統(tǒng)容量和數(shù)據(jù)的高速率傳輸,而結(jié)合多輸入多輸出(Multi-input Multi-output,MIMO)技術(shù)的VLC系統(tǒng)在收發(fā)終端均采用多天線單元,創(chuàng)造并行的無線傳輸信道,在沒有加大發(fā)射功率和系統(tǒng)帶寬的前提之下,大量提升通信質(zhì)量和傳輸速度。在研究MIMO-VLC系統(tǒng)時(shí),我們首先面對的是其光源布局問題。合理的布局不僅是系統(tǒng)正常工作的必要條件,并且可以花最小的代價(jià)解決一些實(shí)際問題。例如,MIMO-VLC系統(tǒng)利用信號的多徑傳播提高系統(tǒng)容量和傳輸速率,但是由于漫反射鏈路的存在,系統(tǒng)會存在碼間干擾(Inter Symbol Interference,ISI),導(dǎo)致誤碼率升高。不同的光源布局會呈現(xiàn)一個(gè)不同的反射功率分布,如何選擇一個(gè)反射功率分布對系統(tǒng)性能影響最小的光源布局成為本領(lǐng)域的一個(gè)研究熱點(diǎn)。由于MIMO-VLC系統(tǒng)在設(shè)計(jì)光源布局時(shí)其設(shè)計(jì)方法和需考慮的關(guān)鍵因素與普通的VLC系統(tǒng)有所不同。因此,本文首先分析了VLC系統(tǒng)模型,其次在考慮漫反射鏈路的情況下分析了結(jié)合有MIMO技術(shù)的VLC系統(tǒng)模型,并提出了其設(shè)計(jì)布局的關(guān)鍵要素:(1)滿足系統(tǒng)基本通信/照明條件;(2)盡可能使漫反射對系統(tǒng)性能影響微弱。最后,通過仿真實(shí)現(xiàn)搜尋保證系統(tǒng)正常運(yùn)行的陣列布局可行區(qū)域,并借助遺傳算法(Genetic Algorithms,GA)在可行區(qū)域內(nèi)進(jìn)行布局優(yōu)化,使得碼間干擾盡可能小地影響系統(tǒng)性能,并仿真了優(yōu)化前后的接收面誤碼率分布情況。
[Abstract]:With the increasing shortage of energy and environmental problems, white LED is more and more widely used in daily and commercial lighting due to its advantages such as high brightness, low energy consumption, long life, stable performance and so on. Indoor visible light communication (Visible Light Communication,VLC) uses white light LED as light source, which can not only provide good lighting, but also realize stable and reliable data communication. However, the low modulation bandwidth of VLC limits the system capacity and the high rate of data transmission. The VLC system combined with multi-input and multi-output (Multi-input Multi-output,MIMO) technology uses multi-antenna units to create parallel wireless transmission channels at transceiver terminals. Without increasing transmission power and system bandwidth, the communication quality and transmission speed are greatly improved. In the study of MIMO-VLC system, we first face the problem of light source layout. Reasonable layout is not only a necessary condition for the normal operation of the system, but also can solve some practical problems at the lowest cost. For example, in MIMO-VLC system, multipath propagation is used to improve the system capacity and transmission rate. However, due to the existence of diffuse reflection link, the system will have inter-symbol interference (Inter Symbol Interference,ISI), which leads to the increase of bit error rate (BER). Different light source configurations will present a different reflected power distribution. How to select a light source layout which has the least effect on system performance has become a research hotspot in this field. The design method and key factors of MIMO-VLC system are different from those of ordinary VLC system. Therefore, this paper first analyzes the VLC system model, and then analyzes the VLC system model with MIMO technology in consideration of diffuse reflection link. The key elements of its design and layout are proposed as follows: (1) satisfying the basic communication / lighting conditions of the system; (2) making diffuse reflection have a weak effect on the performance of the system as much as possible. Finally, the feasible area of array layout is searched by simulation, and the layout is optimized within the feasible area by genetic algorithm (Genetic Algorithms,GA), which makes the inter-symbol interference (ISI) affect the system performance as little as possible. The BER distribution of the receiver before and after the optimization is simulated.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN929.1

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相關(guān)期刊論文 前1條

1 趙婷;李洪祚;宮玉琳;;可見光通信中高階調(diào)制格式研究[J];長春理工大學(xué)學(xué)報(bào)(自然科學(xué)版);2013年05期

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本文編號：2202228