We consider the problem of target localization by a network of passive sensors. When an unknown target emits an acoustic or a radio signal, its position can be localized with multiple sensors using the time difference of arrival (TDOA) information. In this paper, we consider the maximum likelihood formulation of this target localization problem and provide efficient convex relaxations for this nonconvex optimization problem.We also propose a formulation for robust target localization in the presence of sensor location errors. Two Cramer-Rao bounds are derived corresponding to situations with and without sensor node location errors. Simulation results confirm the efficiency and superior performance of the convex relaxation approach as compared to the existing least squares based approach when large sensor node location errors are present.
標簽： 傳感器網絡
上傳時間： 2016-11-27
上傳用戶：xxmluo
是否要先打開ALLEGRO? 不需要(當然你的機器須有CADENCE系統)。生成完封裝后在你的輸出目錄下就會有幾千個器件（全部生成的話）,默認輸出目錄為c:\MySym\. Level里面的Minimum, Nominal, Maximum 是什么意思？ 對應ipc7351A的ABC封裝嗎？ 是的 能否將MOST, NOMINAL, LEAST三種有差別的封裝在命名上也體現出差別？ NOMINAL 的名稱最后沒有后綴，MOST的后綴自動添加“Ｍ”，LEAST的后綴自動添加“L”，你看看生成的庫名稱就知道了。（直插件以及特別的器件，如BGA等是沒有MOST和LEAST級別的，對這類器件只有NOMINAL） IC焊盤用長方形好像比用橢圓形的好，能不能生成長方形的？ 嗯。。。。基本上應該是非直角的焊盤比矩形的焊盤好，我記不得是AMD還是NS還是AD公司專門有篇文檔討論了這個問題，如果沒有記錯的話至少有以下好處：信號質量好、更省空間（特別是緊密設計中）、更省錫量。我過去有一篇帖子有一個倒角焊盤的SKILL，用于晶振電路和高速器件（如DDR的濾波電容)，原因是對寬度比較大的矩形用橢圓焊盤也不合適，這種情況下用自定義的矩形倒角焊盤就比較好了－－－你可以從網上另外一個DDR設計的例子中看到。 當然，我已經在程序中添加了一選擇項，對一些矩形焊盤可以選擇倒角方式. 剛才試了一下，感覺器件的命名的規范性不是太好，另好像不能生成器件的DEVICE文件，我沒RUN完。。。 這個程序的命名方法基本參照IPC-7351，每個人都有自己的命名嗜好，仍是不好統一的；我是比較懶的啦，所以就盡量靠近IPC-7351了。 至于DEVICE，的選項已經添加 (這就是批量程序的好處，代碼中加一行，重新生產的上千上萬個封裝就都有新東西了)。 你的庫都是"-"的,請問用過ALLEGRO的兄弟,你們的FOOTPRINT認"-"嗎?反正我的ALLEGRO只認"_"(下劃線) 用“－”應該沒有問題的，焊盤的命名我用的是"_"（這個一直沒改動過）。 部分絲印畫在焊盤上了。 絲印的問題我早已知道，只是盡量避免開（我有個可配置的SilkGap變量）,不過工作量比較大，有些已經改過，有些還沒有；另外我沒有特別費功夫在絲印上的另一個原因是，我通常最后用AUTO-SILK的來合并相關的層，這樣既方便快捷也統一各個器件的絲印間距，用AUTO-SILK的話絲印線會自動避開SOLDER-MASK的。 點擊allegro后命令行出現E- Can't change to directory: Files\FPM，什么原因？ 我想你一定是將FPM安裝在一個含空格的目錄里面了，比如C:\Program Files\等等之類，在自定義安裝目錄的時候該目錄名不能含有空格，且存放生成的封裝的目錄名也不能含有空格。你如果用默認安裝的話應該是不會有問題的, 默認FPM安裝在C:\FPM，默認存放封裝的目錄為C:\MYSYM 0.04版用spb15.51生成時.allegro會死機.以前版本的Allegro封裝生成器用spb15.51生成時沒有死機現象 我在生成MELF類封裝的時候有過一次死機現象，估計是文件操作錯誤導致ALLEGRO死機，原因是我沒有找到在ｓｋｉｌｌ里面直接生成SHAPE焊盤的方法（FLASH和常規焊盤沒問題）, 查了下資料也沒有找到解決方法，所以只得在外部調用SCRIPT來將就一下了。（下次我再查查看），用SCRIPT的話文件訪問比較頻繁（幸好目前MELF類的器件不多）. 解決辦法： １、對MELF類器件單獨選擇生成，其它的應該可以一次生成。 ２、試試最新的版本(當前0.05) 請說明運行在哪類器件的時候ALLEGRO出錯，如果不是在MELF附近的話，請告知，謝謝。 用FPM0.04生成的封裝好像文件都比較大，比如CAPC、RES等器件，都是300多K，而自己建的或采用PCB Libraries Eval生成的封裝一般才幾十K到100K左右，不知封裝是不是包含了更多的信息？ 我的每個封裝文件包含了幾個文字層（REF,VAL,TOL,DEV,PARTNUMBER等),SILK和ASSEM也是分開的，BOND層和高度信息，還有些定位線(在DISP層）,可能這些越來越豐富的信息加大了生成文件的尺寸.你如果想看有什么內容的話，打開所有層就看見了（或REPORT） 非常感謝 LiWenHui 發現的BUG, 已經找到原因，是下面這行： axlDBChangeDesignExtents( '((-1000 -1000) (1000 1000))) 有尺寸空間開得太大，后又沒有壓縮的原因，現在生成的封裝也只有幾十K了，0.05版已經修復這個BUG了。 Allegro封裝生成器0.04生成do-27封裝不正確,生成封裝的焊盤的位號為a,c.應該是A,B或者1,2才對. 呵呵，DIODE通常管腳名為AC(A = anode, C = cathode) 也有用AK 或 12的， 極少見AB。 除了DIODE和極個別插件以及BGA外，焊盤名字以數字為主, 下次我給DIODE一個選擇項，可以選擇AC 或 12 或 AK, 至于TRANSISTER我就不去區分BCE/CBE/ECB/EBC/GDS/GSD/DSG/DGS/SGD/SDG等了，這樣會沒完沒了的，我將對TRANSISTER強制統一以數字編號了，如果用家非要改變，只得在生成庫后手工修改。
標簽： Footprint Maker 0.08 FPM skill
上傳時間： 2018-01-10
上傳用戶：digitzing
AEC-Q100 qualified ? 12 V and 24 V battery systems compliance ? 3.3 V and 5 V logic compatible I/O ? 8-channel configurable MOSFET pre-driver – High-side (N-channel and P-channel MOS) – Low-side (N-channel MOS) – H-bridge (up to 2 H-bridge) – Peak & Hold (2 loads) ? Operating battery supply voltage 3.8 V to 36 V ? Operating VDD supply voltage 4.5 V to 5.5 V ? All device pins, except the ground pins, withstand at least 40 V ? Programmable gate charge/discharge currents for improving EMI behavior
標簽： configurable Automotive pre-driver suitable channel systems MOSFET fully High side
上傳時間： 2019-03-27
上傳用戶：guaixiaolong
function [R,k,b] = msc(A) % 多元散射校正 % 輸入待處理矩陣，通過多元散射校正，求得校正后的矩陣 %% 獲得矩陣行列數 [m,n] = size(A); %% 求平均光譜 M = mean(A,2); %% 利用最小二乘法求每一列的斜率k和截距b for i = 1:n a = polyfit(M,A(:,i),1); if i == 1 k = a(1); b = a(2); else k = [k,a(1)]; b = [b,a(2)]; end end %% 求得結果 for i = 1:n Ai = (A(:,i)-b(i))/k(i); if i == 1 R = Ai; else R = [R,Ai]; end end
上傳時間： 2020-03-12
上傳用戶：15275387185
Homogeneous Partitioning of the Surveillance Volume discusses the implementation of the first of three sequentially complementary approaches for increasing the probability of target detection within at least some of the cells of the surveillance volume for a spatially nonGaussian or Gaussian “noise” environment that is temporally Gaussian. This approach, identified in the Preface as Approach A, partitions the surveillance volume into homogeneous contiguous subdivisions.
標簽： Receivers Adaptive Antennas and
上傳時間： 2020-05-26
上傳用戶：shancjb
The term economics is generally understood to mean sound management. This is associated with openness, good faith, accurate figures and integrity in company accounts, with transparency ensured through satisfactory standards of good practice in relation to investors and the clients who have placed their trust in an organization’s managers.
標簽： Communication Networks Economy
上傳時間： 2020-05-26
上傳用戶：shancjb
It is more than a decade since GSM was first commercially available. After some unexpected delay, it seems that finally UMTS is here to stay as a 3G system standardised by 3GPP, at least for another ten years. UMTS will enable multi-service, multi-rate and flexible IP native-based mobile technologies to be used in wide area scenarios and also pave the way for a smooth transition from circuit switched voice networks to mobile packet services.
標簽： Management Strategies Resource Radio
上傳時間： 2020-06-01
上傳用戶：shancjb
The first gem of wisdom I ever acquired about consulting, obtained many years ago from a former schoolmate, was to ensure that everything is plugged in: no continuity, no data. Wires carry voltages and currents from one place to another. Their behavior is reasonably simple and predictable—at least for sufficiently low data rates and short lengths—and they can be seen, grabbed, traced, and tugged.
標簽： RF Engineering
上傳時間： 2020-06-01
上傳用戶：shancjb
This paper presents a Hidden Markov Model (HMM)-based speech enhancement method, aiming at reducing non-stationary noise from speech signals. The system is based on the assumption that the speech and the noise are additive and uncorrelated. Cepstral features are used to extract statistical information from both the speech and the noise. A-priori statistical information is collected from long training sequences into ergodic hidden Markov models. Given the ergodic models for the speech and the noise, a compensated speech-noise model is created by means of parallel model combination, using a log-normal approximation. During the compensation, the mean of every mixture in the speech and noise model is stored. The stored means are then used in the enhancement process to create the most likely speech and noise power spectral distributions using the forward algorithm combined with mixture probability. The distributions are used to generate a Wiener filter for every observation. The paper includes a performance evaluation of the speech enhancer for stationary as well as non-stationary noise environment.
標簽： Telecommunications Processing Signal for
上傳時間： 2020-06-01
上傳用戶：shancjb
Telecommunications is today widely understood to mean the electrical means of communicating over a distance. The first form of telecommunications was that of the Telegraph, which was invented quite independently in 1837 by two scientists, Wheatstone and Morse. Telegraphy was on a point-to-point unidirectional basis and relied on trained operators to interpret between the spoken or written word and the special signals sent over the telegraph wire. However, the use of telegraphy did greatly enhance the operations of railways and, of course, the dissemination of news and personal messages between towns.
標簽： Telecommunications Understanding Networks
上傳時間： 2020-06-01
上傳用戶：shancjb
