Qam_and_Qpsk

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

Tutor description

Review of Quadrature Amplitude Modulator (QAM) in digital communication system, generation of Quadrature Phase Shift Keyed (QPSK or 4-PSK) signal and demodulation.

Word Count: 1224
Showing Page: 1/6
Qam and QpskQAM and QPSK:Aim:Review of Quadrature Amplitude Modulator (QAM) in digital communication system, generation of Quadrature Phase Shift Keyed (QPSK or 4-PSK) signal and demodulation.Introduction:The QAM principle: The QAM modulator is of the type shown in Figure 1 below. The two paths to the adder are typically referred to as the I (inphase), and Q (quadrature), arms.Not shown in Figure 1 is any bandlimiting. In a practical situation this would be implemented either at message level - at the input to each multiplier - and/or at the output of the adder. Probably both ! The motivation for QAM comes from the fact that a DSBSC signal occupies twice the bandwidth of the message from which it is derived. This is considered wasteful of resources. QAM restores the balance by placing two independent DSBSC, derived from message #1 and message #2, in the same spectrum space as one DSBSC. The bandwidth imbalance is removed. In digital communications this arrangement is popular. It is used because of its bandwidth conserving (and other) properties.It is not used for multiplexing two independent messages. Given an input binary sequence (message) at the rate of n bit/s, two sequences may be obtained by splitting the bit stream into two paths, each of n/2 bit/s. This is akin to a serial-to-parallel conversion. The two streams become the channel 1 and channel 2 messages of Figure 1. Because of the halved rate the bits in the I and Q paths are stretched to t

Review from student

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

Type your question here (or upload an image)

1820 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