1 / 15

ارتباطات داده (883-40) مقدمه

ارتباطات داده (883-40) مقدمه. دانشکده مهندسی کامپیوتر. نیمسال دوّم 93-92 افشین همّت یار. ریز نمرات. تمرین‌ها تشریحی و تحلیلی 3 نمره هر دو هفته یک تمرین کامپیوتری 4 نمره هر دو هفته یک تمرین امتحان‌ها سیگنال‌ها و سیستم‌ها 2 نمره فصل‌اول و فصل دوم 3 نمره 18 اسفند 1392

iago
Download Presentation

ارتباطات داده (883-40) مقدمه

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ارتباطات داده (883-40)مقدمه دانشکده مهندسی کامپیوتر نیمسال دوّم 93-92 افشین همّتیار

  2. ریز نمرات • تمرین‌ها • تشریحی و تحلیلی 3 نمره هر دو هفته یک تمرین • کامپیوتری 4 نمره هر دو هفته یک تمرین • امتحان‌ها • سیگنال‌ها و سیستم‌ها 2 نمره • فصل‌اول و فصل دوم 3 نمره 18 اسفند 1392 • فصل‌سوم 2 نمره 31 فروردین 1393 • فصل چهارم 2 نمره 14 اردیبهشت 1393 • فصل پنجم 2 نمره 28 اردیبهشت 1393 • فصل ششم 2 نمره 20 خرداد 1393

  3. References • Simon Haykin, “Communication Systems,” 4th Edition, 2001. • B.P. Lathi, “Modern Analog and Digital Communication Systems,” 3rd Edition, 1998. • John J. Proakis, “Digital Communications,”

  4. Contents • Background and Preview • Random Process • Continuous-Wave Modulation • Pulse Modulation • Base-band Pulse Transmission • Signal-Space Analysis • Pass-band Digital Transmission

  5. Background and Preview • Digital Communication System • Communication Channels • Mathematical Models for Communication Channels • Primary Communication Resources • Basic Modes of Communication • Channel Sharing • Information Capacity of Channel

  6. Digital Communication System (1)

  7. Digital Communication System (2) • Information Source • Generates message signals: Voice, Music, Picture, or Data. • Source Encoder • Removes redundant information from message signal and is • responsible for efficient use of channel. • Channel Encoder • Adds controlled redundancy and produces sequence of • symbols regarding channel specifications. • Modulator • Represents symbols in waveforms suitable for transmission • over the physical media of interest.

  8. Communication Channels (1) • Wire-line • (Twisted Pair, Coaxial Cable, . . . ) • Fiber Optic • Wireless (Electromagnetics) • (Broadcast, Mobile, Satellite, . . . ) • Underwater Acoustic • Storage

  9. Communication Channels (2) • Linear or Nonlinear • Time Invariant or Time Variant • Frequency Dependent or Independent • Bandwidth Limited or Power Limited

  10. Communication Channels (3)

  11. Mathematical Models for Communication Channels • Constant R(t) = C.S(t) + n(t) • LTI Filter R(t) = C(t)*S(t) + n(t) • LTV Filter R(t) = C(t,τ)*S(t) + n(t)

  12. Primary Communication Resources • Transmitter Power • Average power of transmitted signal • Channel Bandwidth • Band of frequencies allocated for transmission • Usually one is more important: • Power Limited Channel • Band Limited Channel

  13. Basic Modes of Communications • Point-to-Point • Broadcasting • Unidirectional (Simplex) • Bidirectional (Half and Full Duplex)

  14. Channel Sharing • Multiplexing • Fixed • FDM: Frequency-Division Multiplexing • (WDM: Wavelength-Division Multiplexing) • TDM: Time-Division Multiplexing • CDM: Code-Division Multiplexing • Statistical • Multiple Access • Fixed • FDMA: Frequency-Division Multiple Access • (WDMA: Wavelength-Division Multiple Access) • TDMA: Time-Division Multiple Access • CDMA: Code-Division Multiple Access • Statistical • CSMA: Carrier Sense Multiple Access

  15. Information Capacity of Channel • Shannon’s Theorem • C = B log2(1+SNR) • Channel Capacity in bits/Sec Signal to Noise Ratio (no units) • Channel Bandwidth in Hz

More Related