可見(jiàn)光通信高速移相關(guān)聯(lián)空時(shí)編碼技術(shù)研究
發(fā)布時(shí)間：2018-11-23 15:18
【摘要】：可見(jiàn)光通信(Visible Light Communication,VLC)將照明和通信有機(jī)結(jié)合,利用可見(jiàn)光新頻譜資源,依托廣泛覆蓋的照明燈具,為緩解無(wú)線通信的“頻譜緊張”、“深度覆蓋”和“綠色節(jié)能”等問(wèn)題提供了新手段。本文針對(duì)可見(jiàn)光通信的高速傳輸問(wèn)題,重點(diǎn)研究了移相關(guān)聯(lián)空時(shí)編碼技術(shù),主要研究?jī)?nèi)容和成果總結(jié)如下:1.測(cè)量和分析商用照明LED(Light Emitting Diodes)的直流傳輸特性和交流傳輸特性。測(cè)量了LED的電壓—電流、電流—光通量?jī)煞N轉(zhuǎn)化特性,采用多項(xiàng)式對(duì)LED的非線性進(jìn)行了擬合建模,分析了非線性對(duì)高階調(diào)制信號(hào)的影響。測(cè)量了三種顏色LED燈芯的幅頻響應(yīng)曲線,給出了時(shí)域和頻域預(yù)均衡方法。2.針對(duì)單LED傳輸速率受限的問(wèn)題,提出了多LED移相空時(shí)疊加傳輸方法,實(shí)現(xiàn)了傳輸速率的成倍提升。采用LED內(nèi)部的多個(gè)燈芯實(shí)現(xiàn)并行傳輸,通過(guò)相對(duì)移相后,利用光在空間的自然線性疊加特性,構(gòu)造出了一種等效的多輸入、單輸出傳輸系統(tǒng)。設(shè)計(jì)了分塊移相空時(shí)碼,給出了其快速檢測(cè)算法。理論分析表明其頻譜利用率與LED燈芯的數(shù)目成正比,且在衰落信道條件下可以達(dá)到滿(mǎn)分集。為進(jìn)一步提升頻譜利用率,在分塊移相空時(shí)碼的基礎(chǔ)上,構(gòu)建了塊級(jí)聯(lián)移相空時(shí)碼,設(shè)計(jì)了防止差錯(cuò)傳播的預(yù)編碼方法,分析了其誤比特性能。相比于單路傳輸,塊級(jí)聯(lián)移相空時(shí)碼可以將頻譜利用率提升至N倍(N為L(zhǎng)ED燈芯個(gè)數(shù)),達(dá)到全速率。與可見(jiàn)光通信中常用的OFDM(Orthogonal Frequency Division Multiplexing)的仿真對(duì)比表明,多LED移相空時(shí)碼可以達(dá)到更高的傳輸速率,且抗LED非線性性能更好。3.為了提升系統(tǒng)在低通頻選信道下傳輸性能,將唯一可分解星座對(duì)(Uniquely Factorable Constellation Pair,UFCP)技術(shù)與可見(jiàn)光通信相結(jié)合,構(gòu)造了星座關(guān)聯(lián)的VLC OFDM技術(shù)和星座關(guān)聯(lián)的多LED移相空時(shí)碼。星座關(guān)聯(lián)的VLC OFDM技術(shù)將不同子載波上的符號(hào)之間相互關(guān)聯(lián),在接收端聯(lián)合解調(diào),從而提升了系統(tǒng)的抗頻率選擇特性。在此基礎(chǔ)上,給出了基于星座關(guān)聯(lián)的VLC OFDM的最大似然檢測(cè)方法,分析了VLC OFDM在采用星座關(guān)聯(lián)技術(shù)后所獲得的平均歐氏距離增益。通過(guò)將UFCP技術(shù)與塊級(jí)聯(lián)移相空時(shí)碼相結(jié)合,提出了一種星座關(guān)聯(lián)的塊級(jí)聯(lián)移相空時(shí)碼,其實(shí)質(zhì)在于將塊級(jí)聯(lián)移相空時(shí)碼中不同支路的符號(hào)關(guān)聯(lián)起來(lái),聯(lián)合解調(diào)以獲得增益。數(shù)值仿真結(jié)果表明,引入星座關(guān)聯(lián)的方法可以獲得0.8-1.5 dB的信噪比增益。4.針對(duì)室內(nèi)可見(jiàn)光通信的典型應(yīng)用,設(shè)計(jì)實(shí)現(xiàn)了兩種可見(jiàn)光通信基帶傳輸系統(tǒng)。一是面向中低速可見(jiàn)光通信應(yīng)用需求,設(shè)計(jì)并實(shí)現(xiàn)了50 Mbit/s可見(jiàn)光通信芯片基帶原型系統(tǒng),給出了可見(jiàn)光基帶芯片的系統(tǒng)結(jié)構(gòu)、功能指標(biāo),并詳細(xì)介紹了FPGA上各模塊的實(shí)現(xiàn)流程。二是面向高速可見(jiàn)光通信應(yīng)用需求,利用本文提出的星座關(guān)聯(lián)塊級(jí)聯(lián)移相空時(shí)編碼,采用RGB LED的三個(gè)燈芯實(shí)現(xiàn)了三路信號(hào)的疊加傳輸,設(shè)計(jì)并實(shí)現(xiàn)800 Mbit/s離線處理系統(tǒng)。
[Abstract]:Visible light communication (Visible Light Communication,VLC) combines lighting and communication organically, using the new spectrum resources of visible light, relying on the widely covered lighting lamps, in order to alleviate the "spectrum tension" of wireless communication. Such issues as "deep coverage" and "green energy conservation" provide new means. Aiming at the problem of high speed transmission of visible light communication, this paper focuses on the phase shift associated space-time coding technology. The main research contents and results are summarized as follows: 1. The DC and AC transmission characteristics of commercial lighting LED (Light Emitting Diodes) are measured and analyzed. The voltage-current and current-luminous flux conversion characteristics of LED are measured. The nonlinear characteristics of LED are modeled by polynomial, and the influence of nonlinearity on high-order modulation signals is analyzed. The amplitude-frequency response curves of three color LED cores are measured, and the time-domain and frequency-domain preequalization methods are given. 2. In order to solve the problem of limited transmission rate of single LED, a method of superposition transmission with multiple LED phase shift is proposed, which can increase the transmission rate exponentially. A multi-input and single-output transmission system is constructed by using the natural linear superposition of light in space after relative phase shift. The block phase shift space-time code is designed and its fast detection algorithm is given. Theoretical analysis shows that the spectrum efficiency is proportional to the number of LED cores and can reach full diversity in fading channels. In order to further improve the spectral efficiency, a block concatenated phase-shifted space-time code is constructed on the basis of block phase-shifted space-time code. A precoding method to prevent error propagation is designed, and its bit error performance is analyzed. Compared with single-channel transmission, block concatenated phase-shifted space-time codes can increase the spectral efficiency to N times (N is the number of LED wicks) and achieve full rate. Compared with OFDM (Orthogonal Frequency Division Multiplexing), which is commonly used in visible light communication, the simulation results show that the multi-LED phase-shifted space-time code can achieve higher transmission rate, and the anti-LED nonlinear performance is better. 3. In order to improve the transmission performance of the system in low-pass frequency-selective channels, the unique decomposable constellation pair (Uniquely Factorable Constellation Pair,UFCP) technique is combined with visible light communication to construct the constellation associated VLC OFDM technique and the constellation associated multi-LED phase-shifted space-time code. The constellation associated VLC OFDM technique correlates the symbols on different subcarriers and demodulates them at the receiver, which improves the anti-frequency selection performance of the system. On this basis, the maximum likelihood detection method of VLC OFDM based on constellation correlation is presented, and the average Euclidean distance gain obtained by using constellation correlation technique in VLC OFDM is analyzed. By combining UFCP technology with block concatenated phase-shifted space-time codes, a constellation associated block concatenated phase-shifted space-time codes is proposed. The essence of the proposed codes is to associate the symbols of different branches of block concatenated phase-shifted space-time codes and demodulate them to gain. Numerical simulation results show that the signal-to-noise ratio gain of 0.8-1.5 dB can be obtained by using constellation correlation method. Aiming at the typical application of indoor visible light communication, two kinds of baseband transmission system of visible light communication are designed and implemented. First, the prototype system of 50 Mbit/s visible light communication chip is designed and implemented to meet the application requirement of medium and low speed visible light communication. The system structure and function index of the visible light baseband chip are given. The realization flow of each module on FPGA is introduced in detail. Secondly, for the application of high speed visible light communication, using the concatenated phase shift space-time coding proposed in this paper, using the three cores of RGB LED to realize the superposition transmission of three signals, the 800 Mbit/s off-line processing system is designed and implemented.
【學(xué)位授予單位】：解放軍信息工程大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TN929.1
本文編號(hào)：2351883
[Abstract]:Visible light communication (Visible Light Communication,VLC) combines lighting and communication organically, using the new spectrum resources of visible light, relying on the widely covered lighting lamps, in order to alleviate the "spectrum tension" of wireless communication. Such issues as "deep coverage" and "green energy conservation" provide new means. Aiming at the problem of high speed transmission of visible light communication, this paper focuses on the phase shift associated space-time coding technology. The main research contents and results are summarized as follows: 1. The DC and AC transmission characteristics of commercial lighting LED (Light Emitting Diodes) are measured and analyzed. The voltage-current and current-luminous flux conversion characteristics of LED are measured. The nonlinear characteristics of LED are modeled by polynomial, and the influence of nonlinearity on high-order modulation signals is analyzed. The amplitude-frequency response curves of three color LED cores are measured, and the time-domain and frequency-domain preequalization methods are given. 2. In order to solve the problem of limited transmission rate of single LED, a method of superposition transmission with multiple LED phase shift is proposed, which can increase the transmission rate exponentially. A multi-input and single-output transmission system is constructed by using the natural linear superposition of light in space after relative phase shift. The block phase shift space-time code is designed and its fast detection algorithm is given. Theoretical analysis shows that the spectrum efficiency is proportional to the number of LED cores and can reach full diversity in fading channels. In order to further improve the spectral efficiency, a block concatenated phase-shifted space-time code is constructed on the basis of block phase-shifted space-time code. A precoding method to prevent error propagation is designed, and its bit error performance is analyzed. Compared with single-channel transmission, block concatenated phase-shifted space-time codes can increase the spectral efficiency to N times (N is the number of LED wicks) and achieve full rate. Compared with OFDM (Orthogonal Frequency Division Multiplexing), which is commonly used in visible light communication, the simulation results show that the multi-LED phase-shifted space-time code can achieve higher transmission rate, and the anti-LED nonlinear performance is better. 3. In order to improve the transmission performance of the system in low-pass frequency-selective channels, the unique decomposable constellation pair (Uniquely Factorable Constellation Pair,UFCP) technique is combined with visible light communication to construct the constellation associated VLC OFDM technique and the constellation associated multi-LED phase-shifted space-time code. The constellation associated VLC OFDM technique correlates the symbols on different subcarriers and demodulates them at the receiver, which improves the anti-frequency selection performance of the system. On this basis, the maximum likelihood detection method of VLC OFDM based on constellation correlation is presented, and the average Euclidean distance gain obtained by using constellation correlation technique in VLC OFDM is analyzed. By combining UFCP technology with block concatenated phase-shifted space-time codes, a constellation associated block concatenated phase-shifted space-time codes is proposed. The essence of the proposed codes is to associate the symbols of different branches of block concatenated phase-shifted space-time codes and demodulate them to gain. Numerical simulation results show that the signal-to-noise ratio gain of 0.8-1.5 dB can be obtained by using constellation correlation method. Aiming at the typical application of indoor visible light communication, two kinds of baseband transmission system of visible light communication are designed and implemented. First, the prototype system of 50 Mbit/s visible light communication chip is designed and implemented to meet the application requirement of medium and low speed visible light communication. The system structure and function index of the visible light baseband chip are given. The realization flow of each module on FPGA is introduced in detail. Secondly, for the application of high speed visible light communication, using the concatenated phase shift space-time coding proposed in this paper, using the three cores of RGB LED to realize the superposition transmission of three signals, the 800 Mbit/s off-line processing system is designed and implemented.
【學(xué)位授予單位】：解放軍信息工程大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TN929.1
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 遲楠;王源泉;王一光;黃星星;陸肖元;;Ultra-high-speed single red green blue light-emitting diode-based visible light communication system utilizing advanced modulation formats[J];Chinese Optics Letters;2014年01期
，本文編號(hào)：2351883
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