Quadrature Amplitude Modulation

May 5th, 2015
Studypool Tutor
Price: $10 USD

Tutor description

Quadrature amplitude modulation (QAM) ([pic] /ˈkwɑːm/ or /ˈkæm/ or simply "Q-A-M") is both an analog and a digital modulation scheme. It conveys two analog message signals, or two digital bit streams, by changing (modulating) the amplitudes of two carrier waves, using the amplitude-shift keying (ASK) digital modulation scheme or amplitude modulation (AM) analog modulation scheme.

Word Count: 2301
Showing Page: 1/9
Quadrature Amplitude ModulationQuadrature amplitude modulation(QAM) ([pic]/kwm/or/km/or simply "Q-A-M") is both an analog and a digitalmodulationscheme. It conveys two analog message signals, or two digitalbit streams, by changing (modulating) theamplitudesof twocarrier waves, using theamplitude-shift keying(ASK) digital modulation scheme oramplitude modulation(AM) analog modulation scheme. The two carrier waves, usuallysinusoids, areout of phasewith each other by 90and are thus calledquadraturecarriers or quadrature components hence the name of the scheme. The modulated waves are summed, and the resulting waveform is a combination of bothphase-shift keying(PSK) andamplitude-shift keying(ASK), or (in the analog case) of phase modulation (PM) and amplitude modulation. In the digital QAM case, a finite number of at least two phases and at least two amplitudes are used. PSK modulators are often designed using the QAM principle, but are not considered as QAM since the amplitude of the modulated carrier signal is constant. QAM is used extensively as a modulation scheme for digitaltelecommunicationsystems.Spectral efficienciesof 6 bits/s/Hz can be achieved with QAM.[1]QAM modulation is being used in optical fiber systems as bit rates increase QAM16 and QAM64 can be optically emulated with a 3-pathinterferometer.[2]|Contents ||[hide] ||1Digital QAM ||2Analog QAM ||2.1Fourier

Review from student

Studypool Student
" Solid work, thanks. "
Ask your homework questions. Receive quality answers!

Type your question here (or upload an image)

1821 tutors are online

Brown University





1271 Tutors

California Institute of Technology




2131 Tutors

Carnegie Mellon University




982 Tutors

Columbia University





1256 Tutors

Dartmouth University





2113 Tutors

Emory University





2279 Tutors

Harvard University





599 Tutors

Massachusetts Institute of Technology



2319 Tutors

New York University





1645 Tutors

Notre Dam University





1911 Tutors

Oklahoma University





2122 Tutors

Pennsylvania State University





932 Tutors

Princeton University





1211 Tutors

Stanford University





983 Tutors

University of California





1282 Tutors

Oxford University





123 Tutors

Yale University





2325 Tutors