ΗΥ-330 fall semester 2016

University of Crete Computer Science Department Stefanos Papadakis

Introduction to telecommunication systems theory

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Digital Modulations

QAM

PSK

Examples

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Amplitude Modulation

Plain & Simple y(t) = I(t) · cos(!ct) !c = 2⇡fc

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Amplitude Modulation

Amplitude Shift Keying (ASK)

On Off Keying (OOK)

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Phase Modulation

Constant amplitude

!c = 2⇡fc

y(t) = Ac · cos(!ct+m(t))

m(t) = (B · n� 1)⇡

N

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Phase Modulation

Phase Shift Keying (PSK)

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Frequency Modulation

Frequency Shift Keying (FSK)

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Amplitude & Frequency Modulation?

Quadrature Amplitude Modulation (QAM)

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Quadrature Modulation

Complex Number

Real <-> In-phase

Imaginary <-> Quadrature

z(t) = I(t) · cos(!ct)�Q(t) · sin(!ct)

I(t)

Q(t)

z = x+ i · y

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Quadrature Amplitude Modulation

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Quadrature Amplitude Modulation

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Constellation Diagram

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Constellation Diagram

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Constellation Diagram512-QAM tilted 256-QAM

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Phase-shift keying

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

ConstellationBPSK: 1 bit/symbol

QPSK: 2 bit/symbol

8-PSK: 3 bit/symbol

16-QAM: 4 bit/symbol

64-QAM: 6 bit/symbol

256-QAM: 8 bit/symbol

1024-QAM: 10 bit/symbol

<HY-330> Introduction to telecommunication systems theoryCSD.UoC Stefanos Papadakis fall 2016

Decision Regions