本文關(guān)鍵詞：基于LDPC碼的可見光通信系統(tǒng)性能研究　出處：《哈爾濱工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 可見光通信 可見光信道 光源布局 LDPC碼

【摘要】：可見光通信(VLC)技術(shù)作為一項(xiàng)近幾年興起的新型無線接入技術(shù),以其功耗低、頻帶寬、保密性強(qiáng)和無電磁污染等優(yōu)點(diǎn),得到了世界范圍內(nèi)的關(guān)注。隨著移動(dòng)互聯(lián)和家庭智能的迅速發(fā)展,可見光通信將在其中扮演重要角色。目前,可見光通信系統(tǒng)的研究主要集中在調(diào)制技術(shù)、信道均衡技術(shù)以及提高傳輸速率和可靠性等方面。隨著可見光通信關(guān)鍵技術(shù)和芯片的快速研發(fā),未來的可見光通信將朝著超寬帶,超高速,大吞吐量,大覆蓋范圍和高可靠性的方向發(fā)展,包括移動(dòng)大數(shù)據(jù)和高清影像等對誤碼性能要求高的多媒體業(yè)務(wù)。因此必須尋找一種吞吐量大,適合高速率通信和性能優(yōu)異的可見光通信信道編碼方案。本文主要研究了LDPC碼在可見光通信中的應(yīng)用,首先,深入分析了可見光通信系統(tǒng)結(jié)構(gòu)和可見光信道模型,對可見光信道特性進(jìn)行了理論分析。接著,仿真分析了信道沖擊響應(yīng)等關(guān)鍵參量,并得出了可見光信道的近似數(shù)學(xué)模型。同時(shí),對光源布局進(jìn)行了理論分析,通過對不同房間的實(shí)驗(yàn)仿真,提出了最佳光源布局的原則,并證明了最佳光源布局下的信號(hào)接收質(zhì)量明顯提高。之后,分析了IEEE802.15.7標(biāo)準(zhǔn)RS碼的優(yōu)缺點(diǎn),闡述了可見光通信糾錯(cuò)碼構(gòu)造原則。通過對IEEE802.16e標(biāo)準(zhǔn)LDPC碼的深入研究,構(gòu)造了一種適合可見光通信的QC-LDPC碼,找到了其快速編碼方法,并對其進(jìn)行四環(huán)檢驗(yàn),仿真結(jié)果表明,校驗(yàn)矩陣不存在四環(huán)。接著,研究了LDPC碼各種譯碼方法,基于BP算法和MS算法提出了一種譯碼改進(jìn)算法,并將該算法應(yīng)用到搭建的可見光通信系統(tǒng)仿真模型中,通過對通信平臺(tái)網(wǎng)格化處理找到了信道條件最差的信道,在此基礎(chǔ)上,對乘性因子和迭代次數(shù)對系統(tǒng)誤碼性能的影響展開了研究,根據(jù)仿真結(jié)果確定了改進(jìn)譯碼算法中的迭代次數(shù)和最佳乘性因子。最后,對LDPC碼各譯碼算法的誤碼性能進(jìn)行仿真,并計(jì)算各譯碼算法的復(fù)雜度,結(jié)果表明,改進(jìn)譯碼算法在算法復(fù)雜度和誤碼性能方面實(shí)現(xiàn)了較好的優(yōu)化折中,在最佳光源布局下實(shí)現(xiàn)了房間內(nèi)任意一點(diǎn)的可靠通信,證明了該碼能夠滿足可見光通信信道編碼的構(gòu)造原則,是一種適合可見光通信的信道編碼。
[Abstract]:As a new wireless access technology, visible light communication (VLC) technology has many advantages, such as low power consumption, high frequency bandwidth, strong confidentiality and no electromagnetic pollution. With the rapid development of mobile interconnection and home intelligence, visible light communication will play an important role. At present, the research of visible light communication system is mainly focused on modulation technology. With the rapid development of the key technologies and chips of visible light communication, the future visible light communication will move towards ultra-wideband, ultra-high speed and large throughput. Large coverage and high reliability development, including mobile big data and high-definition video and other high performance requirements for multimedia services, so we must look for a high throughput. This paper mainly studies the application of LDPC code in visible light communication. The structure of visible light communication system and the model of visible light channel are deeply analyzed, and the characteristics of visible light channel are theoretically analyzed. Then, the key parameters such as channel impulse response are simulated and analyzed. The approximate mathematical model of visible light channel is obtained. At the same time, the theory of light source layout is analyzed, and the principle of optimal light source layout is put forward through the experiment simulation of different rooms. It is proved that the signal receiving quality is improved obviously under the optimal light source layout. After that, the advantages and disadvantages of IEEE802.15.7 standard RS code are analyzed. The construction principle of error-correcting code for visible light communication is expounded. A kind of QC-LDPC code suitable for visible light communication is constructed by deeply studying the IEEE802.16e standard LDPC code. The fast coding method is found, and the four-ring test is carried out. The simulation results show that there are no four rings in the check matrix. Then, various decoding methods of LDPC codes are studied. An improved decoding algorithm based on BP algorithm and MS algorithm is proposed and applied to the simulation model of visible light communication system. The channel with the worst channel condition is found through the grid processing of the communication platform. On this basis, the effects of multiplicative factors and iterations on the error performance of the system are studied. According to the simulation results, the iterative times and the best multiplicative factor of the improved decoding algorithm are determined. Finally, the error performance of each decoding algorithm of LDPC codes is simulated, and the complexity of each decoding algorithm is calculated. The results show that the improved decoding algorithm achieves a better compromise in terms of algorithm complexity and error rate performance, and realizes reliable communication at any point in the room under the optimal light source layout. It is proved that this code can meet the construction principle of channel coding for visible light communication and is a channel coding suitable for visible light communication.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TN929.1;TN911.22

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 婁鵬華;張洪明;郎凱;姚敏玉;徐正元;;基于室內(nèi)可見光照明的位置服務(wù)系統(tǒng)[J];光電子.激光;2012年12期

2 遲楠;黃星星;王一光;;基于先進(jìn)調(diào)制的高速可見光通信技術(shù)[J];中興通訊技術(shù);2014年06期

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本文編號(hào)：1403991