Documents about Quadrature Amplitude Modulation
QPSKNotes
UCSD, ECE 157
Excerpt: ... QPSK and QAM Notes 1 Introduction In lab, we will study demodulating both quadrature phase shift keyed signals (QPSK) as well as quadrature amplitude modulated signals (QAM). Here we discuss the modications for the Costas loop for QPSK and QAM demodu ...
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lec38
Allan Hancock College, ELEC 2500
Excerpt: ... pling theorem; pulse code modulation (PCM); Nyquist bandwidth; advantages and disadvantages of PCM; companding; delta modulation; amplitude-shift keying (ASK); symbol rate vs. bit rate; frequency-shift keying (FSK); optimum receivers; binary phase-shift keying (BPSK); BPSK receiver; quadrature phase-shift keying (QPSK); quadrature amplitude modulation (QAM); constellations; parity checks and their limitations; cyclic redundancy check (CRC) Page 6 codes; automatic repeat request (ARQ); linear block codes; parity-check and generator matrices; code rate; minimum distance; Hamming distance; maximumlikelihood decoding; coding gain A guide to the ELEC2500 exam Question 5 public switched telephone system (PSTN); hierarchical views of PSTN; switching devices; pulse and tone dialing; time-division multiplexing of voice signals; circuit switching vs. packet switching; frequency re-use in cellular systems; influence of cell size on cellular system capacity; time- and frequency-division duplexing; evolution of second g ...
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ece4304c08_schedule
Uni. Worcester, ECE 4304
Excerpt: ... ECE4304:DigitalCommunicationSystems CTerm2008 Lecture 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 TopicsCovered CourseIntroduction;ProbabilityTheoryReview StatisticalAverages;RandomProcessesIntroduction;Mean, Co ...
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ece4304c09_schedule
Uni. Worcester, ECE 4304
Excerpt: ... ECE4304:DigitalCommunicationSystems CTerm2009 Lecture 1 2 3 4 5 6 7 8 9 10 11 12 TopicsCovered CourseIntroduction;ProbabilityTheoryReview StatisticalAverages;RandomProcessesIntroduction;Mean, Correlation,andCovarianceFunctions ErgodicProcesses;LTIFi ...
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Lab_7_Task_List
University College of the Caribbean, ECE 6713
Excerpt: ... EE345S: Real Time DSP Lab Tasks Receiver Objective: Lab 7: Quadrature Amplitude Modulation (QAM) This lab deals with implementation of a Quadrature amplitude modulation (QAM) receiver system. Lab slides: All the slides referred in this document are taken from the pdf for this lab available here: http:/users.ece.utexas.edu/~bevans/courses/realtime/lectures/laboratory/c6713/SLIDE S/qam.pdf Block diagram: Please refer to Slide 13-18 for the overall block diagram. The block diagram only shows some parts of the QAM receiver. In actuality, the receiver has other blocks like Automatic Gain Control (AGC), Carrier Detect Subsystem, and Symbol clock recovery in addition to the blocks mentioned in the above block diagram. Since this is a one week lab, we will be implementing only the blocks mentioned in Slide 13-18. Task 1: Raised cosine filter implementation using a filter bank (rascos.exe) The transmitter has a SQRT raised cosine filter. So does the receiver. However, we will comb ...
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lect20
Georgia Tech, ECE 4601
Excerpt: ... ow. 000 001 011 010 110 111 101 100 -7 -5 -3 -1 X E0 +1 +3 +5 +7 & % 0 c 2007, Georgia Institute of Technology (lect20 3) ' $ Quadrature Amplitude Modulation (QAM) QAM signals can be thought of a independent PAM on the inphase (cosine) and quadrature (sine) carrier components. During any baud interval the transmitted waveform is 2E0 ac cos(2fc t) - as sin(2fc t) sm (t) = m m T where {c,s} am {1, 3, 5, (M - 1)} and 2E0 is the energy of the signal with the lowest amplitude, i.e., when ac , as = 1. m m & % 0 c 2007, Georgia Institute of Technology (lect20 4) ' $ Quadrature Amplitude Modulation (QAM) QAM signals can be expressed in terms of signal vectors. Since the functions cos 2fc t and sin 2fc t, with fc T 1, are orthogonal over the interval (0, T ), we have two basis functions f1 (t) = 2 cos 2fc t T 2 sin 2fc t f2 (t) = - T Then sm (t) = ac E0 f1 (t) + as E0 f2 (t), m = 1, . . . , M, 0 t T m m Hence & sm (t) sm = E0 ac , as m m % 0 c 2007, Georgia Institute of Techn ...
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LabNotes_5
Allan Hancock College, ENGN 3214
Excerpt: ... AUSTRALIAN NATIONAL UNIVERSITY Department of Engineering ENGN3214 Telecommunications Systems Laboratory #5: Quadrature Amplitude Modulation (QAM) 1 Aim To investigate and understand the decoding of Quadrature Amplitude Modulation (QAM). To investigate the noise and bandwidth effects in QAM. 1.1 Quadrature Amplitude Modulation A standard double sideband (DSB) signal wastes bandwidth since the upper sideband contains the same information as the lower sideband. One possibility for efficiently using the bandwidth consumed by DSB is to modulate two independent signals by assigning a single sideband signal to the lower sideband (LSB) and another single sideband signal to the upper sideband (USB). In prac 4 on SSB we demonstrated that it was indeed possible to transmit two independent signals in the LSB and USB. We called this scheme Independent Sideband Modulation. This was achieved using IQ modulation and demodulation. In digital communications a similar IQ mod/demod procedure is exploited to transmit separa ...
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RCL-7
East Los Angeles College, EZ 412
Excerpt: ... ELEC6014 (EZ412/612) Radio Communications Networks and Systems S Chen Revision of Lecture Six We have discussed phase shift keying, in particular, one bit per symbol BPSK and two bits per symbol QPSK Carrier recovery operation and clock recovery operation, in particular, Time-2 carrier recovery: suitable for binary modulation scheme Time-2, early-late, zero crossing clock recovery schemes: suitable for binary signalling, and synchroniser clock recovery: generally applicable Carrier recovery and clock recovery are important, as each transceiver has a pair This lecture looks into bandwidth much more ecient modulation scheme called quadrature amplitude modulation , with emphasis on general design considerations of digital modulation scheme When one gains bandwidth eciency, what is penalty ? (hint: From channel capacity, one can trade-o bandwidth / SNR. What about power eciency?) 73 ELEC6014 (EZ412/612) Radio Communications Networks and Systems S Chen Linear and Nonlinear Mod ...
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MODEM-L1
East Los Angeles College, EL 334
Excerpt: ... over the communication medium reliably Why carrier communication (modulation): low frequency signal cannot travel far, also most spectral resource (channels) are in RF 2 ELEC3028 Digital Transmission MODEM S Chen Digital Modulation In the old day, communications were analogue, analogue modulation techniques include amplitude modulation (AM), frequency modulation (FM), and phase modulation (PM) Communications today are mostly all digital, equivalent digital modulation forms exist: amplitude shift keying (ASK), frequency shift keying (FSK), or phase shift keying (PSK) Sin waveform A sin (2fc t + ): amplitude A, frequency fc , phase three kinds of modulation A large number of other digital modulations are in use, and often combinations are employed We will consider quadrature amplitude modulation (QAM), which is a combination of ASK and PSK 3 ELEC3028 Digital Transmission MODEM S Chen Quadrature Amplitude Modulation cos ( t) x i ( k) bit stream s/p q const. map ...
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WCG_3
Allan Hancock College, WIN 20027
Excerpt: ... COIS 20027 Digital Telecommunications and Networks, Winter Term 2001 Page 1 of 1 _ COIS 20027 Digital Telecommunications & Networks Winter Term 2001 Weekly Contents Guide (WCG) Week 3: Data Communications Concepts and Technology Objectives Textbook Goldman'2001, 3rd edition Chapter 3 "Data Communications Concepts" Objectives 1 4, pp. 76 77 Chapter 4 "Basic Data Communications Technology" Objectives 1 3, pp. 111 Set readings Textbook Goldman'2001, 3rd edition Chapter 3 "Data Communications Concepts" Chapter 4 "Basic Data Communications Technology" Topics End-to-end data communications, pp. 77 78 Computer to MODEM, pp. 78 91 Practical Advice and Information, pp. 80 81 Within the MODEM, pp. 91 102 Measuring Phase Shift, pp. 95 96 In Sharper Focus, pp. 97 98 Quadrature Amplitude Modulation , pp. 98 99 In Sharper Focus, p ...
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Lab_6_Task_List
University College of the Caribbean, ECE 6713
Excerpt: ... EE345S: Real Time DSP Lab Tasks Transmitter Objective: Lab 6: Quadrature Amplitude Modulation (QAM) This lab deals with implementation of a Quadrature amplitude modulation (QAM) transmitter system, used for digital data transmission over bandpass channels. Lab slides: All the slides referred in this document are taken from the pdf for this lab available here: http:/users.ece.utexas.edu/~bevans/courses/realtime/lectures/laboratory/c6713/SLIDE S/qam.pdf Block diagram: Please refer to Slide 13-9 for the block diagram of the symbol generation and Slide 132 for the overall block diagram. Task 1:Differential quadrant encoding (Code Composer) We will be implementing the 16 point QAM constellation on Slide 13-8 using the differential encoder block on Table 1 on Slide 13-9 followed by a Symbol Mapper. Write a DiffEncode function which takes 4 bits as inputs: Q1n, Q2n, Y1nprev and Y2nprev and returns Y1n and Y2n as the outputs. Please use the table on Slide 13-9 to impleme ...
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qam-notes
Brookdale, RADIO 4503
Excerpt: ... Doc. no. ESS140/ext:10, rev. A Notes on Quadrature Amplitude Modulation Erik Strm o October 22, 2002 1 Introduction This document should be viewed as a complement to Sections 7.3.3, 7.5.6, and 7.6.5 of Proakis and Salehis book [1]. In particular, an error in the books equation (7.6.71) is pointed out, and a corrected formula is presented. 2 Quadrature Modulation A block diagram for a generic inphase quadrature phase modulator (IQ-modulator) is found in Figure 1. We see that the transmitted signal can be viewed as the sum of two PAM processes with dierent pulse shapes: I (t) in the top (in-phase) branch and Q (t) in the lower (quadrature) branch, where I = Q = 2 gT (t) cos(2fc t) Eg 2 gT (t) sin(2fc t), Eg and where Eg is the energy of the pulse shape gT (t). The pulse shape and the carrier frequency fc is chosen such that the power spectral density of the transmitted signal will t the frequency response of the channel. As implied by the IQ-modulator block diagram, the signals ...
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notes4
SUNY Albany, CSI 416
Excerpt: ... fact that a signal is present); the remaining power is split between two identical sidebands, though only one of these is needed since they contain identical information. 10 Quadrature Amplitude modulation : It is a modulation scheme which conveys data by changing (modulating) the amplitude of two carrier waves. These two waves, usually sinusoids, are out of phase with each other by 90 and are thus called quadrature. Quadrature Amplitude Modulation (QAM) combines phase shift keying and amplitude shift keying to encode multiple bits per state change. The set of graphs given in the lecture slides represents different combinations of different bit levels and different bandwidth at the receiver. Ak represents the change of amplitude and Bk represents the change of frequency. 3 11 Pulse Code modulation It is a digital representation of an analog signal where the magnitude of the signal is sampled regularly at uniform intervals, then quantized to a series of symbols in a digital (usually binary) code. Sampli ...
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lecture11
Allan Hancock College, ENGN 3226
Excerpt: ... s um(t) = gT (t)Amc cos 2fct gT (t)Ams sin 2fct where gT (t) is a square wave with amplitude 2Es/T and width T , so that we are using a pair of quadrature carriers Note that binary phase modulation is identical to binary PAM A value of interest is the minimum Euclidean distance which plays an important role in determining bit error rate performance in the presence of AWGN. 22 ENGN3226: Digital Communications L#11 00101011 Quadrature Amplitude Modulation (QAM) For MPSK, signals were constrained to have equal energies. The representative signal points therefore lay on a circle in 2-D space In quadrature amplitude modulation (QAM) we allow dierent energies. QAM can be considered as a combination of digital amplitude modulation and digital phase modulation 23 ENGN3226: Digital Communications L#11 00101011 QAM Each bandpass waveform is represented according to a distinct amplitude/phase combination umn(t) = AmgT (t) cos(2fct + n) 24 ENGN3226: Digital Communicat ...
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arch-intro
Dallas, EE 6345
Excerpt: ... The University of Texas at Dallas Erik Jonsson School of Engineering & Computer Science INTERNET AND PSTN ARCHITECTURES Notes prepared for EE 6345 by Professor Cyrus D. Cantrell, P.E. AugustDecember 2007 c C. D. Cantrell (08/2007) The University of Texas at Dallas Erik Jonsson School of Engineering & Computer Science A PLANETARY-SCALE DIGITAL SYSTEM c NASA The University of Texas at Dallas Erik Jonsson School of Engineering & Computer Science A PLANETARY-SCALE DIGITAL SYSTEM A visitor from space would be able to conclude that a planetary-scale digital system exists on Earth without descending to the surface Waveforms of satellite communications signals indicate digital modulation (mostly phase-shift keying (PSK) and quadrature amplitude modulation (QAM) Wide geographical distribution of uplinks to satellites The major components of this planetary-scale digital system are the Internet and the public switched telephone network (PSTN) EE 6345 surveys the digital architectures of the Internet a ...
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L5610704
WVU, EE 561
Excerpt: ... e in-phase component. y axis is the quadrature component. Called a signal constellation diagram. 2007 Example Signal Constellation Diagram: BPSK xR (t ) { + 1,-1} xI (t ) = 0 2007 Example Signal Constellation Diagram: QPSK xR (t ) { + 1,-1} xI (t ) { + 1,-1} QPSK: Quadri-phase shift keying 2007 Example Signal Constellation Diagram: QAM xR (t ) { + 3,+1,-1,-3} xI (t ) { + 3,+1,-1,-3} QAM: Quadrature Amplitude Modulation 2007 Interpretation of Signal Constellation Diagrams Axis are labeled with xR(t) and xI(t). Possible signals are plotted as points. Signal power is proportional to distance from origin. Probability of mistaking one signal for another is related to the distance between signal points. The received signal will be corrupted by noise. The receiver selects the signal point closest to the received signal. 2007 Example: A Received QAM Transmission xR (t ) { + 3,+1,-1,-3} xI (t ) { + 3,+1,-1,-3} received signal 2007 A New Way of Viewing Modulation Th ...
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lecture16_ece461
University of Illinois, Urbana Champaign, ECE 461
Excerpt: ... e transmitted two real baseband signals in the same frequency band and doubled the data rate. This is possible as now we are using total double sided bandwidth of 2W instead of W as in wireline channel. The resulting RF signal is still real. However, the magnitude of the spectrum of the RF signal need not be symmetric around fc and -fc . Thus, we can now have the RF signal x(t) which is x(t) = xb1 (t) 2 cos 2fc t - xb2 (t) 2 sin 2fc t (4) signals xb1 (t) and xb2 (t) are obtained at the receiver by multiplying x(t) by The baseband 2 cos 2fc t and 2 sin 2fc t separately and then passing both the outputs through the low pass filters. Here we are modulating the amplitude of the carrier by the baseband data. Such a scheme is called amplitude modulation. When we modulate both sin and cos parts of the carrier by two undependent baseband signals, the scheme is called Quadrature Amplitude Modulation (QAM). 1 Can we up-convert one more baseband signal and still be able to recover it at the receiver? The answer is ...
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lecture16_ece461
Berkeley, EE 121
Excerpt: ... equency band, they are orthogonal to each other. Thus, we could have transmitted two real baseband signals in the same frequency band and doubled the data rate. This is possible as now we are using total double sided bandwidth of 2W instead of W as in wireline channel. The resulting RF signal is still real. However, the magnitude of the spectrum of the RF signal need not be symmetric around fc and fc . Thus, we can now have the RF signal x(t) which is x(t) = xb1 (t) 2 cos 2fc t xb2 (t) 2 sin 2fc t (4) signals xb1 (t) and xb2 (t) are obtained at the receiver by multiplying x(t) by The baseband 2 cos 2fc t and 2 sin 2fc t separately and then passing both the outputs through the low pass lters. Here we are modulating the amplitude of the carrier by the baseband data. Such a scheme is called amplitude modulation. When we modulate both sin and cos parts of the carrier by two undependent baseband signals, the scheme is called Quadrature Amplitude Modulation (QAM). 1 Can we up-conv ...
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LitSurveyReport
University College of the Caribbean, ECE 382
Excerpt: ... Modeling and Simulation of an ADSL Transmitter by Kripa Venkatachalam and Qiu Wu Abstract This paper gives a short introduction of Asymmetric Digital Subscriber Line (ADSL) technology and briefly discusses its importance. ADSL uses Discrete Multito ...
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course_overview-2008
Berkeley, EE 224
Excerpt: ... Course Outline: 0. Overview (1 lecture) Basic blocks of a digital communication system. Source-channel separation. Channel models. History of the field. 1. Gaussian Channel with No Bandwidth Constraint (5 lectures) Signal space approach as geometric framework for representing modulation schemes. Examples of modulation techniques. Maximum a posterior (MAP) and maximum likelihood (ML) receivers. Error probability analysis. Achieving capacity via orthogonal signaling. 2. Ideal Bandlimited Gaussian Channel ( 5 lectures) Pulse amplitude modulation for baseband transmission. Nyquist criterion for zero intersymbol interference (ISI). Nyquist pulses. Passband and quadrature amplitude modulation . Complex discrete-time baseband representation. Implementation of QAM. Performance of uncoded systems versus capacity. Carrier and phase recovery. 3. Channel Coding (4 lectures) Linear binary clock codes, Soft and hard decision decoding. Binary convolutional codes. Viterbi algorithm for maximum likelihood sequence detection ( ...
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eecs 141b
UC Irvine, EECS 141b
Excerpt: ... block diagrams. Understand and analyze equalizers. Understand and analyze sychronization systems. Understand the basics of information theory and error correcting codes. The students are expected to have a background that includes probability theory, and analog and digital signal processing, and Fourier transform theory, random processes, and analog communication systems. Geometric representation of signals Conversion of continuous AWGN channel into vector channel Optimum receivers, maximum a posteriori detection Maximum likelihood detection, likelihood functions Matched filter and correlation receiver Probability of error Pulse and quadrature amplitude modulation Phase shift keying Frequency shift keying Minimum shift keying Digital signaling through bandlimited channels: Nyquist criterion Principles of equalization Adaptive equalization Carrier recovery Timing recovery Course Outcomes: Prerequisites By Topic: Lecture Topics: Introduction to information theory Error correction Linear block codes Convolu ...
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outline
University of Illinois, Urbana Champaign, ECE 461
Excerpt: ... ECE361: Communications II Instructor: Pramod Viswanath, 127 CSL, 244-8999, pramodv@uiuc. Oce hours: 10-11am Th after class in 368 Everitt or by appointment. Teaching Assistant: Chun-Wei Lam, Oce hours to be decided. WebPage: The course webpage will b ...
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courseinfo
UCSB, ECE 146
Excerpt: ... s are due in the homework box before your next lab session. (Late submissions will not be accepted.) Course Topical Outline: I. Why digital? Digital communications applications. Block diagram of a digital communication link II. The representation of analog signals in digital form-Sampling and quantization, Pulse code modulation, with applications to voice communications 1 III. Modulation: Baseband and passband channels and signals; Complex baseband representation of passband signals and systems; Signals as vectors; Linear Modulation and the Nyquist criterion; Linear modulation formats: Pulse Amplitude Modulation (PAM); Quadrature Amplitude Modulation (QAM), Phase Shift Keying (PSK); Orthogonal Modulation; Differential Modulation; Bandwidth of linearly modulated signals III. Modulation and detection: Additive White Gaussian Noise (AWGN) channel model; White Gaussian Noise (WGN) through correlators and filters; Matched Filter Receiver as Signal-to-Noise Ratio maximizer; Example: Binary signaling with linea ...
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