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Modulation / Transmission
Modulation can be defined as the process, or result of the process, of varying
the characteristic of a carrier, in accordance with an information input signal from one
input (voice or data). The modulated wave can be a varying electrical signal tranmitted
over a wire carrier or an electromagnetic signal transmitted by any type transmitter.
Transmission is the access methodology used to define the sharing of the
spectrum bandwidth between all input voice channels and/or the data channels.
Analog POTS / PSTN Networks
In legacy... POTS networks the following modulation / transmission technologies are
common;
| Input -> |
Modulation-> |
Transmission |
| Voice |
Analog modulation |
1 Channel (0-3600) Hertz |
For data transmission
| Input -> |
Modulation-> |
Transmission |
| Data |
Amplitude (ASK)
Frequency (FSK)
Phase (PSK)
Multilevel : 4-PSK, Quadrature (16-QAM) |
1 or 3 (ISDN)
Channels : 0-128Kbps
or
Multiple calls on TDM
Aggregate of 1.544Mpbs
24 Channels |
Wireless Network
For instance, in wireless word the typical architectures are often seen;
Analog Cellular Telephone (AMGP)
| Input -> |
Modulation-> |
Transmission |
| Voice |
FM (Frequency Modulation) |
FDMA |
Digital Cellular Telephone (IS-54, IS-95) and Data
| Input -> |
Coding -> |
Modulation -> |
Transmission |
| Voice |
ADPCM / VSELP / QCELP |
DQPSK / GMSK / GFSK / B.QPSK |
FDMA / TDMA
CDMA (Voice)
DS CDMA (Data) |
| Data |
|
B.QPSK |
DS CDMA (Data) |
Wireless LAN
| Input -> |
LLC/MAC |
Modulation -> |
Transmission |
| Data |
CSMA/CA
EYNPMA / CFMA |
16-4 PPM / GMSK
GFSK / DB.QPSK |
CDMA / DS CDMA
FH CDMA / DS CDMA |
Introductions
Introduction :
Modulation Schemes
Modulation/Bandwidth - Broadband
Access
More Advanced :
Analog and
Digital Communication Theory
Analog and Digital Modulation
Amplitude
- Frequency Modulation
Data Encoding : Amplitude,
Frequency, Phase
- Binary Phase-Shift Keying (BPSK)
- Differential QPSK (QPSK)
- Quanterly Phase Shift Keying (QPSK)
- Binary Frequency-Shift Keying (BFSK)
- Binary Amplitude-Shift Keying (BASK)
Digital modulation (BPSK, DPSK, DESPK, QSPK, BFSK, M-ary systems, MSK)
QAM Modulation : 4-QAM, 16-QAM,
64-QAM
Multicarrier modulation and OFDM;
OFDM for DTTB
OFDM - DVBT Standard
OFDM Receivers
for Broadband-Transmission
Digital : Pulse Code Modulation and TDM
Pulse Code Modulation (PCM)
and (ADPCM)
Pulse Amplitude Modulation (PAM)
Multiplexing
- Binary Frequency-Shift Keying (BFSK)
- Frequency Division Multiplexing (FDM)
- Time Division Multiplexing (TDM)
- Statistical Time Division Multiplexing (STDM)
Digital Multiple Access Method
Tutorial of FDMA, TDMA,
and CDMA
CDMA : All about CDMA : Spreading Sequences
GPS : Global Positionning System
Global Positioning
System Overview
Modulation and Speech
Acoustics
of Spoken Language Dafydd Gibbon
Investigating Amplitude
Modulation for Speech Signal
Related Topics
Error Detection / Correction
Digital Hierarchy
Phase Noise in Amplifiers
and Oscillators
Signals and
Systems
Modems Technology
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