In: Electrical Engineering
Post a one paragraph summary about the different types of modulations used with modems. ( Pls no copy from the internet its just 1 paragraph )
Here are the three general types of modulation used in
modems:
FSK - Frequency Shifted Keying
QPSK - Quadrature section Shifted Keying
QAM - Quadrature Amplitude Modulation
cutting-edge modems use a combination of the above common
modulation systems and compression to reap excessive knowledge
switch rates (14.4 Kbps and up).
FSK - Frequency Shift Keying
Frequency Shift Keying (or FSK) is the frequency modulation of a
service that represents digital intelligence. For Simplex or half
Duplex operation, a single carrier (1170 Hz) is used - verbal
exchange can best be transmitted in one course at a time. A Mark or
1 is represented with the aid of 1270 Hz, and a space or 0 is
represented by 1070 Hz. The following diagram suggests the Voice
Channel with Simplex/half of Duplex FSK.
QAM - Quadrature Amplitude Modulation
Quadrature Amplitude Modulation refers to QPSK with Amplitude
Modulation. In actual fact, it is a mixture of section modulation
and amplitude modulation. QAM phase modulates the carrier and
likewise modulates the amplitude of the carrier.
QPSK - Quadrature segment Shift Keying
Quadrature segment Shift Keying employs transferring the segment of
the carrier at a 600 baud expense plus an encoding method. QPSK is
used in Bell 212A-suitable modems and V.22 - each are 1200 bps Full
Duplex necessities. The originate modem transmits at 1200 Hz, and
receives on 2400 Hz. The reply modem receives on 1200 Hz, and
transmits on 2400 Hz.