08-IntroductionToDigitalModulation - Digital Communication...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Introduction to Digital Modulation Instructor: M.A. Ingram ECE4823 Digital Communication Transmitter User Interface Encoder Modulator RF Front End antenna bits 0110 more bits 011001 waveforms (symbols) Frequency up-conversion and amplification ± A simplified block diagram: interleaver Digital Communications Receiver ± A simplified block diagram: User Interface Decoder Demodulator RF Front End antenna bits 0110 “soft detections” of coded bits 011001 waveforms (faded symbols plus noise) Low-noise amplification and frequency down-conversion deinterleaver Symbols ± In each symbol period, T s , a digital modulator maps N coded bits word to a transmitted waveform from a set of M=2 N possible waveforms ± Each waveform corresponds to an information symbol, x n ± For Binary symbols, N=1 Detection ± The job of the receiver is to determine which symbols were sent and to reconstruct the bit stream that created them Definitions ± Bit Rate (bits per sec or bps) ± Bandwidth Efficiency (bps/Hz) where B is the bandwidth occupied by the signal S T N R / = B R B / = η
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Shannon Theorem ± In a non-fading channel, the maximum bandwidth efficiency, or Shannon Capacity is SNR = signal-to-noise ratio () SNR MAX B + = 1 log 2 η Pulses ± A symbol period, T s , suggests a localization in time ± Localization in frequency is also
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/20/2012 for the course EE 301 taught by Professor Ahmetçakar during the Spring '11 term at Gazi Üniversitesi.

Page1 / 5

08-IntroductionToDigitalModulation - Digital Communication...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online