【正文】 ian lensblur function typically used as a parameter for image resolution in analyzing fine detailed astronomical and medical images [4], [5]. The distance of separation between the images of the transmit elements can be determined by perspective projection analysis (as described in [6]) considering circular transmitting elements. Given a fixedfocal length f of the camera, pixel side length s and a spatial distance between the circumference of two adjacent LEDs, the circumference of two transmit element images will be separated by im = fds pixels in each dimension. Therefore the separation between thecircumference of two transmit element images will be equal to the threshold (=s) at a distance d = f between the LEA and camera. This implies that, multiplexing in visual MIMO is possible only when d  d and when d d each transmit element has to transmit the same information whereby diversity bining at the receiver can ensure an SNR gain and hence an equivalent capacity gain.B. Dependence on viewing angle We can observe in equation (3) that the channel quality depreciates with the viewing angle  (angle between the camera image plane and LEA surface plane). Two images which are clearly separated in the image plane may look overlapped when viewed from an angle. Such distortions can significantly depreciate the signal quality and the detection capability leading to errors and thus reduction in the data rates. Moreover such an angular view also reduces the achievable multiplexing transmission range. This is because when the camera image detector plane is at an angle  to the transmitter array the effective spatial separation between two neighboringtransmit elements bees (as shown inFig. 3). From the earlier discussion on the resolvability of images, it implies that the distance upto which multiplexing can be achieved in visual MIMO then reduces toC. Distance dependent MIMO gainsIn the visual MIMO channel, for a static transmitter and receiver, the image of the LEA transmit elements captured by the camera spans one pixel or multiple pixels. Further, the image plane is spanned by images of each transmit element clearly delineated and the size of image span depending on the focus (concentration ratio) of the camera. As illustrated in Fig. 4, at short distances between the transmitter and receiver, each transmitting element of the LEA looks clearly focused on a unique set of pixels and the images of these elements can be detected from the plete image. In contrast, at a large distance between the transmitter and receiver, the image of each transmit element looks clearly unfocused and thus the signal from all the transmitting elements of the LEA is directed to typically one or few pixels. This suggests that at short distances, the system can offer large ”multiplexing” gains by using the transmitting elements to signal independent bitstreams or equivalently realizing ”parallel” channels. On the other hand, at large distances, there can only be a ”diversity” gain where by the same bits are signaled on each of the transmit elements. These distance dependent gains in visual MIMO is in contrast to the RF MIMO channel, where the rich scattering channel matrix typically allows a continuous tradeoff between diversity and multiplexing gains [24], [27].Fig. 4. Distance dependent Multiplexing and Diversity modesV. VISUAL MIMO CHANNEL CAPACITYTo quantify the perspective dependent multiplexing and diversity gains in visual MIMO we use the channel capacity of the visual MIMO channel as a metric which is given as, where W is the receiver sampling rate (camera framerate), d is the threshold multiplexing distance from equation (6). SNRcam。 j) from equation (3) and AWGN noise nk(i。i。 viewing angle between each transmit element kand receiving pixel (i。 j) represents the concentration ratio of the kth transmit element of an LEA on pixel (i。 j) in each pixel with image coordinates (i。Linux 操作系統(tǒng)至少具有三部分：BootLoader（引導(dǎo)系統(tǒng)）、Kernel（內(nèi)核）、Rootfs（根文件系統(tǒng)）。本文設(shè)計的系統(tǒng)所使用的 WIFI 無線網(wǎng)卡是 TOTOLINK 公司的 N200UA，這款 WIFI無線網(wǎng)卡的優(yōu)點在于外置天線，我們可以根據(jù)需要選用特殊形狀以及高增益的天線。而且易擴展，傳輸可靠，組網(wǎng)便捷。接收數(shù)據(jù)觀察者一般為終端計算器或者其它監(jiān)控設(shè)備，甚至是連接外部世界的萬維網(wǎng)，數(shù)據(jù)采集觀察者通過主動查詢或者被動接收的方式分析無線傳感器網(wǎng)絡(luò)的數(shù)據(jù)信息，并最終完成數(shù)據(jù)的分析、應(yīng)用。第10周～第12周 調(diào)試測試 電路調(diào)試 軟件調(diào)試。然后設(shè)計 WIFI 無線傳感器節(jié)點的硬件結(jié)構(gòu)。加州大學(xué)伯克利分校研究了傳感器網(wǎng)絡(luò)的數(shù)據(jù)查詢技術(shù),提出了實現(xiàn)可動態(tài)調(diào)整的連續(xù)查詢處理方法和管理傳感器網(wǎng)絡(luò)上多查詢方法,并研制了一個感知數(shù)據(jù)庫系統(tǒng)TinyDB。除此之外，國家 863 計劃、973 計劃也對無線傳感器網(wǎng)絡(luò)的研究進行了相關(guān)規(guī)劃。能根據(jù)實際情況設(shè)計無線傳感器網(wǎng)絡(luò)的規(guī)模，有利于應(yīng)用范圍的擴展。 指導(dǎo)教師簽字 系主任簽字 年 月 日 開題報告本課題研究的目的、意義；國內(nèi)外研究現(xiàn)狀；擬采取的研究路線；進度安排； 社會信息化日新月異,新技術(shù)層出不窮?？梢詣討B(tài)拓撲，無線傳感器網(wǎng)絡(luò)中可以隨時添加或減少節(jié)點而并不影響網(wǎng)絡(luò)其他節(jié)點數(shù)據(jù)的正常傳輸。 2）國外的研究現(xiàn)狀 在傳感器網(wǎng)絡(luò)方面,加州大學(xué)伯克利分校提出了應(yīng)用網(wǎng)絡(luò)連通性重構(gòu)傳感器位置的方法,并研究出一個專門用于傳感器網(wǎng)絡(luò)節(jié)點的操作系統(tǒng)TinyOS。?無線傳感器網(wǎng)絡(luò)壽命長短與節(jié)點功耗大小息息相關(guān)，應(yīng)致力于降低功耗。然后進行軟件設(shè)計，了解嵌入式Linus系統(tǒng)的開發(fā)環(huán)境，再進行基于FT245 USB芯片Linus驅(qū)動系統(tǒng)的設(shè)計，配置內(nèi)核，使系統(tǒng)支持 USB 接口的 WIFI 無線網(wǎng)卡。5. 文獻綜述（2000字以上，列出主要參考文獻） 無線傳感器網(wǎng)絡(luò)的三個基本要素包括：無線傳感器網(wǎng)絡(luò)節(jié)點、覆蓋環(huán)境感知對象和接收數(shù)據(jù)觀察者。 無線傳感器網(wǎng)絡(luò)組成形式如圖 12 所示，其工作原理：首先分布于監(jiān)控區(qū)域的眾多傳感器節(jié)點通過無線通信的方式自組織成一個有傳播梯度的多跳網(wǎng)絡(luò)，接著某個傳感器節(jié)點采集接收到覆蓋范圍感知對象的有效數(shù)據(jù)，此節(jié)點將數(shù)據(jù)發(fā)送給周圍選擇的鄰居節(jié)點，鄰居節(jié)點再傳遞給自身周圍的鄰居節(jié)點，數(shù)據(jù)經(jīng)過多跳傳遞給匯聚節(jié)點（sink），匯聚節(jié)點最后再傳遞給接收數(shù)據(jù)觀察者，從而完成整個無線網(wǎng)絡(luò)的通信功能。本設(shè)計中，處理器選用 Ateml 公司的ARM芯片AT91SAM9G45，主頻達400MHZ。Linux 是開放源代碼的，不存在黑箱技術(shù)，全球有眾多 Linux 愛好者，對 Linux 發(fā)展提供強大技術(shù)支持。 驅(qū)動程序設(shè)計好后，需要將其編譯生成二進制文件，驅(qū)動程序不同于應(yīng)用程序的編譯，由于驅(qū)動程序是 Linux 內(nèi)核的一部分，所以需要將驅(qū)動程序源碼放到 Linux 內(nèi)核源碼中。 j), and N is the noise matrix. Noise in optical wireless is dominated by shot noise from background light sources and typically modeled as AWGN [16], [18]. Each element n(i。 j) is given aswhere R is the responsitivity, Ro() is the Lambertian radiation pattern of the optical transmitting element [16] with halfpower angle , Alens is the area of the camera lens, is the camera fieldofview (fov) and dk。j and the viewing angle k。 j), is primarily dependent on the concentration ratio ck(i。這可能是可行的克服大傳輸?shù)臄?shù)據(jù)速率限制光無線通過相機接收器和光的范圍通過一個我們稱之為“概念”的發(fā)射發(fā)射器