lecture24a - 1 Modulation and demodulation transmission...

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

View Full Document Right Arrow Icon

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

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 Modulation and demodulation transmission media coaxial line twisted pair optical fiber free space (EM wave) usually more than one stream of information channel = region of the transmitted frequency spectrum assigned to particular users or services Some definitions baseband signal- the original low-frequency signal modulation- translation to the channel frequency demodulation- recovery of baseband signal f ( t ) = baseband signal e ( t ) = transmitted or modulated signal c = frequency corresponding to center of channel 2 Frequency/ phase modulation generalization of the concept of phase- if we write then if ( t ) = t + then and We can modulate the phase or frequency according to the baseband signal f ( t ) . Note that the amplitude stays constant! )) ( cos( ) ( t t x = ) cos( ) ( + = t t x c dt d = Frequency/ phase modulation Phase modulation Frequency modulation )) ( cos( ) ( t Af t t e c + = = = dt t f A dt d ) ( ) ) ( cos( ) ( + = dt...
View Full Document

Page1 / 13

lecture24a - 1 Modulation and demodulation transmission...

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