3. 3. Noncoherent Binary Modulation Techniques
|
|
- Aubrey Dawson
- 6 years ago
- Views:
Transcription
1 3. 3. Noncoherent Binary Modulation Techniques A digital communication receiver with no provision make for carrier phase recovery is said to be noncoherent. A. Noncoherent Orthogonal Modulation Scheme. For a binary signaling scheme that involves the use of two signals s 1 ( t ), s ( t ), 0 t T which are orthogonal with equal energy, let g 1 ( t ), g ( t ), denote the phase-shifted version of s 1 ( t ), s ( t ), res., which remain orthogonal and of equal energy. This scheme is referred to as noncoherent orthogonal modulation. 0 t T
2 At the receiver, the received signal x(t) can be expressed as follows x ( t ) = g g 1 ( t ) + n ( t ), ( t ) + n ( t ), s s 1 ( t ) ( t ) sent, sent, 0 0 t t T T The receiver tries to discriminate between s 1 (t) and s (t), regardless of the carrier phase. This goal can be achieved by the following receiver structure: x (t ) Matched to 1 (t) Matched to (t) Envelope detector Envelope detector Sample at t = T Sample at t = T l 1 Comparison device If l1 > l choose If l1 < l choose Figure 1. Binary receiver for noncoherent orthogonal modulation l s s 1 ( t ) ( t Gong
3 An noncoherent matched filter may be viewed as being equivalent to a quadrature receiver, as illustrated below. The quadrature receiver itself has two channel (recall that QPSK receiver). Let 1 (t) and (t) be the orthonormal set of s 1 (t) and s (t) and i ( ) be the version of i (t) that results from shifting the carrier phase by -90 degrees. The quadrature receiver is shown in Figure where i = 1,. ~ t In-phase channel x(t) (t) i T dt 0 Square -law device x Ii l i Square + rooter T dt 0 Square -law device x Qi ~ ( t ) i Qradrature channel Figure
4 Remark. The average probability of error for the noncoherent receiver, Figure 1, or equivalently Figure, is given by a simple formula P e 1 exp E = N0 (1) where E is the signal energy per symbol and N 0 / is the noise spectral density. We list this result here without proof. The proof can be found the text Gong 4
5 B. Noncoherent BFSK For the binary FSK case, the transmitted signal is Eb nc + i si ( t) = cos(f it), 0 t Tb i = 1, fi =, nc = integer, i = 1, T Tb b i.e., 1 s 1 0 s ( t) using frequency ( t)using frequency f f 1 Thus the noncoherent binary FSK is a special case of noncoherent orthogonal modulation with T = T b and E = Eb, where T b is the bit duration and E b is the signal energy per bit. From (1), we have the average probability of error (bit error rate) for noncoherent BFSK is P 1 E exp b N e = Gong 5
6 Matched to / cos f t T b 1 Envelope detector Sample at t = T b x(t) 0 t T b Matched to / cosf t T b 0 t T b Envelope detector Sample at t = T b l 1 Comparison device l If l1 > l choose If l1 < l choose 1 0 Figure 3. Noncoherent receiver for BFSK Remark. When comparing the error performance of noncoherent FSK with coherent PSK, it is seen that for the same P e, noncoherent FSK requires approximately 1 db more E b /N 0 than does BFSK (for P 10 4 e ), because coherent reference signals need not be generated. Therefore, almost all FSK receivers use noncoherent detection. In the following, we will see that the same phenomenon occurs for noncoherent DPSK and PSK.
7 C. Differential Phase-shift Keying (DPSK) Transmitter s two operations: (1) differential encoding of the input binary sequence and () phase-shift keying Generation of DPSK: For an input binary sequence b sequence { d k } is determined by { k }, a differential encoded d k = dk 1 bk or dk = dk 1 bk where denotes the modulo operation and the overbar denotes Gong 7
8 Table 1. Illustrating the generation of DPSK signal Differentially encoded sequence Corresponding phase shift index k: { b k } { d k } ref. bit dk = dk 1 bk { ( k)} Remark. DPSK is an another example of noncoherent orthogonal modulation, when it is considered over two bit intervals. In this case, from (1) we get the average probability of error for DPSK is P e 1 E exp = b N 0 since T = T b and E = E b.
9 Remark. When comparing the error performance of () with that of coherent PSK, it is seen that for the same P e, DPSK requires approximately 1 db more E b /N 0 than does BPSK (for P 10 4 e ). It is easier to implement a DPSK system than a PSK system, since the DPSK receiver does not need phase Gong 9
10 4. 4. M-ary Modulation Techniques Error Probability of M-ary Digital PAM Signals Signal Representation of M-ary PSK Signal Representation of M-ary Gong 10
11 A. Error Probability of M-ary Digital PAM Signals Quaternary case: s ( t) = (3/ ), s ( t) = (1/ ), 1 a a s 3( t) = (1/ ) a, ands 4 ( t) = (3/ ) a, for 0 t T P e = 3 a erfc 4 T N 0 where d = a T is the minimum distance of the polar quaternary signal constellation. = 3 erfc 4 d N 0 m 1 = 00 m = 01 m 3 = 11 m 4 = 10 s Z 1 Z Z 3 Z = a T s1 a T 11 a T 1 = s31 = 3 a T s41= a T 0 a T 1( t ) Signal Constellation of Quaternary Signaling Scheme under Gray Code
12 Try for M = 8, which has the signal constellation as below (Gray code). Show that (1) () d 1 d Pe (000) = Pe (111) = erfc N 0 Pe (001) = Pe (011) = erfc N 0 Z 1 Z Z 3 Z 4 Z 5 Z 6 Z 7 Z s 11 = 7 d 3d s 1 = 5 d s d = d s d s51 = d s61 = d 41 = s71 = d s81 = d 31 d 0 0 d d 3d 1( t ) where d = a constellation. T which is the minimum distance of the above signal In general, for M-ary PAM, if the signal points then M M 1 d, L, d, d, d, d, L, d P e M 1 = erfc M d N 0 s 11, s1, L, sm 1 are
13 B. M-ary PSK Scheme: The phase of carrier takes on one of M possible values, namely, i = ( i 1 ) / M, i = 1,..., M A M-ary signal set is represented as s ( t) i E (i 1) = cos(f ct + ), i = 1,...,M, 0 t T M T where T is the symbol duration and E is the signal energy per symbol. The carrier frequency where n c is a fixed integer. f c = n c / Gong 13
14 Similar as we did for QPSK, each signal s i (t) can be represented by the following two orthogonal functions with unit energy: 1( t) = cos(f ct) and ( t) = sin(f ct) T T Thus, the signal constellation of M-ary PSK is two-dimensional. The M messages are equally spaced one circle of radius and center at the origin, see Figure 1 for an example of octa-psk. Figure 1. Signal Constellation for octa- PSK (M = 8). The decision boundaries are shown as dashed Gong 14
15 The coordinates of the received signal given s i (t) was transmitted is (i 1) x I = E cos + n M I, (i 1) xq = E cos + nq, i = 1,..., M M where n I and n Q are Gaussian random variables with zero mean and variance N 0 / (why?). Remark. The probability of correct reception is to integrate the shaded area. This probability can be bounded by some bound. Therefore, for large values of E/N 0, the probability of symbol error is approximately given by s / i M / M P e, M PSK Q E N 0 M sin 4, M (A)
16 C. M-ary FSK In an M-ary FSK scheme, the transmitted signals are defined by s i E ( t) = cos [ f0 + ( i 1) f ] t, 0 t T, i = 1,.., M T where f 0 T is taken as an integer for convenience and ( f ) min = 1/(T ) is the minimum frequency spacing such that adjacent signals are orthogonal (recall this result form MSK). For coherent M-ary FSK, the optimum receiver consists of a bank of M correlations or matched filters. At the sampling times t = kt, the receiver makes decisions based on the largest matched filter output. The probability of symbol error can be upper bounded by E P, ( M 1) Q (B) e M FSK N0 where E = Eb (log M ) is the energy per symbol and M is the size of the symbol set.
17 5. Multi-carrier Modulation and OFDM Applications of M-ary FSK: multicarrier modulation and OFDM Goal: for combating ISI Multicarrier modulation is a way to transmit digital data through bandlimited channel. Design of a bandwidth-efficient communication system in the presence of channel distortion or equivalently ISI, is to divide the available channel bandwidth into a number of equal-bandwidth subchannels, where the bandwidth of each channel is sufficiently narrow so that the frequency response characteristics of the subchannels are nearly equal. Such a division of the overall bandwidth into smaller subchannels is illustrated in Figure Gong 17
18 @G. Gong 18
19 Description: Number of Subchannels: N = W / f Then data symbol is transmitted by frequency-division multiplexing (FDM). This is known as a multicarrier modulation system. Orthogonality: Each subchannel is associated a carrier f i, where f i = f + ( i 1) f, i = 1,, N 0 L which is the mid-frequency in the ith subchannel. If the subcarriers are orthogonal over the symbol duration T, then it is referred to as orthogonal frequency-division multiplexing (OFDM). Thus OFDM is a special case of multicarrier Gong 19
20 Description (Cont.): ISI Reduction: the subcarriers are spaced by 1/T s Hz, where T s is the symbol duration of the subcarriers, then T ofdm, the symbol duration of the OFDM system is related by T s = NT ofdm By selecting N to be sufficiently large, the symbol interval T s of the subcarriers can be made significantly larger than the time duration of the channel-time dispersion. Hence, ISI can be made arbitrarily small by selection of N. In other words, each subchannel appears to have a fixed frequency response C(f k ), k = 0, 1,, N - Gong 0
21 @G. Gong 1
22 @G. Gong
23 @G. Gong 3
24 OFDM Implemented by IDFT and Gong 4
25 Disadvantage: A major problem with the multicarrier modulation in general and OFDM system in particular is the high peak-to-average power ratio (PAR) that is inherent in the transmitted signal. Applications: High-speed transmission over telephone lines, such as digital subcarrier lines. This type of OFDM modulator has also been called discrete multitone (DMT) modulator. OFDM is also used indigital audio broadcasting in Europe and other parts of the worldand in digital cellular communication Gong 5
26 6. 6. Comparisonof of Digital Modulation Systems A. Bit Error Probabilities from Symbol Error Probabilities There are two approaches to define an equivalent bit error probability, P b, or bit error rate (BER), from a symbol error probability, P s. It depends on (1) structure of the signal space, and () the mapping of the signal space points into equivalent bit Gong 6
27 Definition 1. We assume that in going from one signal point to an adjacent signal point, only one bit in the binary word representing the signal changes. In this case, P b = log P s M Remark. M-ary PSK, if a Gray code is employed and M- ary QAM are of the Gong 7
28 Definition. Denote n = log M. We assume that all symbol errors are equally likely. We define P b as the ratio of A, the average number of bit errors per n-bit symbols to n, number of bits per symbol. In the following, we will give an explicit formula for P b. Notice that - Each symbol is in error in an M-ary system with probability P s ( M - For a given symbol error, suppose that k bits are in error. There are n k 1 ) ways that this can happen, which results P b n A 1 n P s = = k n n k = 1 k ( M 1 ) = M P s ( M 1 ) P / s for large M.
29 Remark. M-ary FSK is of this case. B. Bandwidth Efficiencies of M-ary Digital Comm. Systems (DCS) Goal: Consider the bandwidth efficiencies in terms of bits per second per hertz (bps/hz) of bandwidth of various digital modulation schemes. For a M-ary DCS, let R b denote the bit rate and R s symbol rate. Then R b = (log M ) R s For a M-ary PSK, QAM, DPSK, the null to null bandwidth is B M, X = log R b M = R B M b =, X 0. 5 (log M ) (bps/hz)
30 For a M-ary FSK, consider the spacing between frequency is minimum. Then the bandwidth is B coh =, MFSK B coh R b = ( M + log = 3 ) R M log M, MFSK + M 3 b (bps/hz) Table 1. Bandwidth Efficiencies of M-ary Signals M : PSK DPSK QAM : FSK 1 Gong 30
31 Remark: (1) M-ary PSK and M-ary QAM have -dimensional signal space and they are both bandwidth efficient (or called spectral efficient). () MFSK has M-dimensional signal space and it is bandwidth inefficient. Note. The other parameter used in comparing performance (power efficiencies) of different schemes is E/N 0, the ratio of symbol energy to noise power spectral density. In other words, it is to make comparisons between different DSCs on the basis of the relative signal power needed to support a given received information rate assuming identical noise environment.
32 Shannon s system capacity C of an AWGN channel: C = W log (1 + P/WN 0 ) bits/s R > C / = R b / W 4 R = C Bandwidth limited region R < C M-PSK M-QAM M= 8 16 E b M-FSK Power limited region / N 0 ( db ) Figure 1. Band Width Efficiency Plane P e = 5 10
33 7. 7. Synchronization Synchronization at three levels: A. Carrier synchronization (or called carrier recovery): for estimation of carrier phase and frequency. When the coherent detection is used, the knowledge of both the frequency and phase of the carrier is necessary. In other words, there has to be phase concurrence between the incoming carrier and a replica of it in the receiver. This is achieved by employing a phase-locked loop (PLL). The following figure shows a block diagram for carrier synchronization for M-ary Gong 33
34 Received M-ary PSK signal Mth power-law Phase-locked loop BPF LPF If M =, this loop is called a squaring loop. VCO Frequency divide by M Figure 1. Mth Power Loop To data demodulator/detector
35 B. Symbol Synchronization (or called clock recovery) The receiver has to know the instant of time at which the modulation can change its state., i.e., the starting and finishing times of the individual symbols, so that it may determine when to sample and when to quench the product integrator. The estimation of these times is called symbol synchronization or clock recovery. Note. There are typically a very large number of carrier cycles per symbol period, this second level of synchronization is much coarser than phase synchronization (PS), and is usually done with different circuitry than that used for Gong 35
36 One of methods that can achieve this goal is to employ a closed-loop symbol synchronizer. Among the class of closed-loop symbol synchronizers, the early/late-gate synchronizer is the most popular one which shown in Figure 3. g(t) a a T t 0 T T T 0 T T 0 T 0 + T (a) Rectangular pulse g(t) (b) Output of filter matched to g(t) Gong 36
37 Late gate d = 0T T d dt y 1 Absolute value y1 VCO Loop filter F() e = y y1 + timing T d 0 dt y Absolute value y Early gate Figure 3. Early/late-gate data synchronizer
38 C. Frame Synchronization Almost all digital data steams have some sort of frame structure. This is to say that the data stream is organized into uniformly sized groups of bits. For a receiver to make sense of the incoming data stream, the receive needs to be synchronized with the data streams frame structure. This is called frame synchronization. This is usually accomplished with the aid of some special signaling procedure from the transmitter. The simplest frame synchronization aid is the frame marker, for example, in T1 system, for a total of 193 bit, one bit is to used as the frame Gong 38
39 The frame marker could be a single bit, or a short pattern of bits that the transmitter injects periodically into the data stream. The receiver must know the pattern and the injection interval. See Figure Gong 39
40 n bits K bits n bits K bits Data stream n bits K bits n bits K bits Receiver generated frame marker replica Figure 4. Frame marker Gong 40
41 The receiver, having achieved symbol synchronization, correlated the known pattern with the incoming data stream at the known injection interval. If the receiver is not in synchronization with the framing pattern, the accumulated correlation will be low, otherwise, it should be nearly perfect, blemished only by an occasional detection error. A good synchronization codeword is one that has the property that the absolute value of its correlation sidelobes is small. The bit sequences with the property that their largest sidelobe has a magnitude of unity are known as Barker sequences. Unfortunately, the Barker sequences only exist for the length less than Gong 41
42 8. Applications to Digital Cellular Communication Systems In this section, we will present an overview of two types of digital cellular communications systems that are currently in use. One is the GSM ( Global System for Mobile Communication) systems that is widely used in Europe and other parts of the world. It employs time-division multiple access (TDMA) to accommodate multiple users. The second is the CDMA system based on Interim Standard 95 (IS-95) that is widely used in North America and some countries in the Far East. Remark. The extended versions of GSM and IS-95 are UMTS (Universal Mobile Telecommunications Systems, 1998 or W-CDMA) and CDMA 000, respectively.
43 analog speech RPE- LPC speech coder 13 kbps Channel coder.8 kbps Block interleaver Channel measurement bits Burst assembler and encryption 7 other users TDMA multiplexer 70.8 kbps GMSK modulator Frequency hopping synthesizer To transmitter (a) Modulator PN code generator Received signal LPF and A/O converter Buffer Matched filter Channel equalizer Decryption and deinterleaving Channel decoder Speech synthesis Frequency synthesizer (b) Demodulator PN code generator Functional block diagram of modulator and demodulator for GSM
44 Summary of Parameters in GSM System System Parameters Uplink frequency band Downlink frequency band Number of carriers/band Multiple-access method Number of users/carrier Date rate/carrier Speech-coding rate Speech encoder Coded-speech rate Modulation Interleaver Frequency-hopping rate Specification MHz MHz 15 TDMA Kbps 13 KHz RPE-LPC.8 kbps GMSK with BT = 0.30 Block 17 Gong 44
45 Multiple Access Methods
46 The CDMA Cocktail Party This is great stuff Where is she Who called How long will this take Who knows Where is the meeting You know that How can I get there Can I go home? Where is the office
47 Code Division Multiplexing Access (CDMA) Code Division Multiplexing Access (CDMA) Multiple users share a common channel simultaneously by using different codes Narrowband user information is spread into a much wider spectrum by the spreading code The signal from other users will be seen as a background noise: multiple access interference (MAI) The limit of the maximum number of users in the system is determined by interference due to multiple access and multipath fading: Adding one user to CDMA system will only cause graceful degradation of quality Theoretically, no fixed maximum number of Gong 47
48 Code Division Multiplexing Access (CDMA) (Cont.) Code Division Multiplexing Access (CDMA) (Cont.) Received signal PSD Despread signal PSD for user 1 user 1 user M Despreading user M signal power Interference power Bandwidth Bandwidth user 1 user user 3 user 4 user user 3 user 4 CDMA is an interference-limited multiple access scheme The signal from other users will be seen as a background noise: Gong access interference (MAI) 48
49 CDMA System Design Voice Coding Forward Link Generation CODEC bps 4800 bps 400 bps 100 bps R = 1/ Convolutional Encoder and Repetition User Address Mask (ESN) Block Interleaver Long Code PN Generator 19. ksps 1.88 Mcps Decimator 19. ksps Power Control Bit Decimator MUX Wt Hz 1.88 Mcps I PN QPN Cell Power Control VOCODER Voice Coding Reverse Link Generation I PN CODEC bps 4800 bps 400 bps 100 bps R = 1/3 8.8 Convolutional ksps Encoder and Repetition 8.8 Block ksps Interleaver User Address Mask Walsh Cover 307. khz 1.88 Long Mcps Code PN Generator Data Burst Randomizer 1.88 Mcps QPN 1/ PN Chip Dela D Mobile
50 The CDMA Rate Families IS-95 defines the 9600 bps family of rates (Rate Set 1) 9600, 4800, 400, and 100 bps Can select one of the four rates every 0 ms frame bps family of rates (Rate Set ) 14400, 700, 3600, and 1800 bps Can select one of the four rates every 0 ms frame Extended rates (extended Rate Set 1) Adds 1900, 38400, and bps At most four rates can be active Can select one of the four active rates every 0 ms frame
51 Variable-Rate Vocoder 0 ms Packets Full Rate 8.55 kbps 64 kbps PCM Encoder Decoder 1/ Rate 4 kbps 1/4 Rate kbps Decoder Encoder 64 kbps PCM 1/8 Rate 0.8 kbps
52 Link Waveform CDMA Forward Link Waveform Pilot Channel Sync Channel Paging Channel Traffic Channel QTSO CDMA REVERSE Link Waveform Access Channel Traffic Channel QTSO
53 PN code generator I channel Pilot channel and other traffic channels in same cell Hadamard (Walsh) sequence Baseband shaping + filter Data 9.6 kbps 4.8 kbps.4 kbps 1. kbps Mask Rate ½, L = 9 Convolution encoder with repetition Long code generator Decimator Block inter- Carrier leaver generator Block diagram of IS-95 forward link Baseband shaping Gong 53 filter PN code generator Q channel -90 deg. Pilot channel and other traffic channels in same cell To transmitter
54 Reverse CDMA Channel REVERSE CDMA CHANNEL (1.3 MHz channel received by base station) Access Ch 1 Access Ch n Traffic Ch 1 Traffic Ch m Addressed by Long Code PNs
55 Reverse Traffic Channel Structure for Rate Set 1 Reverse Traffic Channel Add Frame Information Quality Indicators (1, 8, 0, Bits (17, 80, 40, or 8.6 kbps or 0 bits/frame) 4.0 kbps 16 bits/frame).0 kbps 0.8 kbps Add 8 bit Encoder Tail 9.6 kbps 4.8 kbps.4 kbps 1. kbps Convolutional Encoder r=1/3, K=9 Code Symbol 8.8 ksps 14.4 ksps 7. ksps 3.6 ksps Symbol Repetition Code Symbol 8.8 ksps 8.8 ksps Block Interleaver Code Symbol I-channel Sequence 1.88 Mcps 64-ary Orthogonal Modulator Modulation Symbol (Walsh chip) 4.8 ksps (307. kcps) Frame Data Rate Data Burst Randomizer PN chip 1.88 Mcps Long Code Generator 1/ PN chip Delay = ns D Q-channel Sequence 1.88 Mcps I Q Baseband Filter Baseband Filter I(t) cos(f c t) Q(t) sin(f c t) s(t) Long Code Mask
56 Summary of Parameters in IS-95 System System Parameters Uplink frequency band Downlink frequency band Number of carriers/band Multiple-access method Number of users/carrier Chip rate Speech coder Speech rate Interleaver Channel encoder Modulation Signature sequences PN sequence Specification MHz MHz 0 CDMA Mbps Variable rate, CELP 9600, 4800, 40, 100 Block R=1/,L=9(D), R=1/, L=9(U) BPSK with QPSK spreading (D) 64-ary orthogonal with QPSK spreading (U) Hadamard (Walsh) of length (long code), 15 (spreading codes)
QUESTION BANK SUBJECT: DIGITAL COMMUNICATION (15EC61)
QUESTION BANK SUBJECT: DIGITAL COMMUNICATION (15EC61) Module 1 1. Explain Digital communication system with a neat block diagram. 2. What are the differences between digital and analog communication systems?
More informationDigital Modulation Schemes
Digital Modulation Schemes 1. In binary data transmission DPSK is preferred to PSK because (a) a coherent carrier is not required to be generated at the receiver (b) for a given energy per bit, the probability
More informationDigital modulation techniques
Outline Introduction Signal, random variable, random process and spectra Analog modulation Analog to digital conversion Digital transmission through baseband channels Signal space representation Optimal
More informationSC - Single carrier systems One carrier carries data stream
Digital modulation SC - Single carrier systems One carrier carries data stream MC - Multi-carrier systems Many carriers are used for data transmission. Data stream is divided into sub-streams and each
More informationChapter 7 Multiple Division Techniques for Traffic Channels
Introduction to Wireless & Mobile Systems Chapter 7 Multiple Division Techniques for Traffic Channels Outline Introduction Concepts and Models for Multiple Divisions Frequency Division Multiple Access
More informationMobile & Wireless Networking. Lecture 2: Wireless Transmission (2/2)
192620010 Mobile & Wireless Networking Lecture 2: Wireless Transmission (2/2) [Schiller, Section 2.6 & 2.7] [Reader Part 1: OFDM: An architecture for the fourth generation] Geert Heijenk Outline of Lecture
More informationEC 6501 DIGITAL COMMUNICATION UNIT - IV PART A
EC 6501 DIGITAL COMMUNICATION UNIT - IV PART A 1. Distinguish coherent vs non coherent digital modulation techniques. [N/D-16] a. Coherent detection: In this method the local carrier generated at the receiver
More informationPrinciples of Communications
Principles of Communications Meixia Tao Shanghai Jiao Tong University Chapter 8: Digital Modulation Techniques Textbook: Ch 8.4 8.5, Ch 10.1-10.5 1 Topics to be Covered data baseband Digital modulator
More informationDIGITAL COMMUNICATIONS SYSTEMS. MSc in Electronic Technologies and Communications
DIGITAL COMMUNICATIONS SYSTEMS MSc in Electronic Technologies and Communications Bandpass binary signalling The common techniques of bandpass binary signalling are: - On-off keying (OOK), also known as
More informationChapter 7. Multiple Division Techniques
Chapter 7 Multiple Division Techniques 1 Outline Frequency Division Multiple Access (FDMA) Division Multiple Access (TDMA) Code Division Multiple Access (CDMA) Comparison of FDMA, TDMA, and CDMA Walsh
More informationQUESTION BANK EC 1351 DIGITAL COMMUNICATION YEAR / SEM : III / VI UNIT I- PULSE MODULATION PART-A (2 Marks) 1. What is the purpose of sample and hold
QUESTION BANK EC 1351 DIGITAL COMMUNICATION YEAR / SEM : III / VI UNIT I- PULSE MODULATION PART-A (2 Marks) 1. What is the purpose of sample and hold circuit 2. What is the difference between natural sampling
More informationCH 5. Air Interface of the IS-95A CDMA System
CH 5. Air Interface of the IS-95A CDMA System 1 Contents Summary of IS-95A Physical Layer Parameters Forward Link Structure Pilot, Sync, Paging, and Traffic Channels Channel Coding, Interleaving, Data
More informationCH 4. Air Interface of the IS-95A CDMA System
CH 4. Air Interface of the IS-95A CDMA System 1 Contents Summary of IS-95A Physical Layer Parameters Forward Link Structure Pilot, Sync, Paging, and Traffic Channels Channel Coding, Interleaving, Data
More informationTSTE17 System Design, CDIO. General project hints. Behavioral Model. General project hints, cont. Lecture 5. Required documents Modulation, cont.
TSTE17 System Design, CDIO Lecture 5 1 General project hints 2 Project hints and deadline suggestions Required documents Modulation, cont. Requirement specification Channel coding Design specification
More informationPrinciples of Communications
Principles of Communications Weiyao Lin Shanghai Jiao Tong University Chapter 8: Digital Modulation Techniques Textbook: Ch 8.4.8.7 2009/2010 Meixia Tao @ SJTU 1 Topics to be Covered data baseband Digital
More informationEXPERIMENT WISE VIVA QUESTIONS
EXPERIMENT WISE VIVA QUESTIONS Pulse Code Modulation: 1. Draw the block diagram of basic digital communication system. How it is different from analog communication system. 2. What are the advantages of
More informationMSK has three important properties. However, the PSD of the MSK only drops by 10log 10 9 = 9.54 db below its midband value at ft b = 0.
Gaussian MSK MSK has three important properties Constant envelope (why?) Relatively narrow bandwidth Coherent detection performance equivalent to that of QPSK However, the PSD of the MSK only drops by
More informationSpread Spectrum Techniques
0 Spread Spectrum Techniques Contents 1 1. Overview 2. Pseudonoise Sequences 3. Direct Sequence Spread Spectrum Systems 4. Frequency Hopping Systems 5. Synchronization 6. Applications 2 1. Overview Basic
More informationObjectives. Presentation Outline. Digital Modulation Revision
Digital Modulation Revision Professor Richard Harris Objectives To identify the key points from the lecture material presented in the Digital Modulation section of this paper. What is in the examination
More informationRevision of Wireless Channel
Revision of Wireless Channel Quick recap system block diagram CODEC MODEM Wireless Channel Previous three lectures looked into wireless mobile channels To understand mobile communication technologies,
More informationChapter 6 Passband Data Transmission
Chapter 6 Passband Data ransmission Different methods of digital modulation Outline PSK(Phase-shift keying), QAM(Quad. amp. mod), FSK(Phase-shift keying) Coherent detection of modulated signals in AWGN
More informationFundamentals of Digital Communication
Fundamentals of Digital Communication Network Infrastructures A.A. 2017/18 Digital communication system Analog Digital Input Signal Analog/ Digital Low Pass Filter Sampler Quantizer Source Encoder Channel
More informationLecture 9: Spread Spectrum Modulation Techniques
Lecture 9: Spread Spectrum Modulation Techniques Spread spectrum (SS) modulation techniques employ a transmission bandwidth which is several orders of magnitude greater than the minimum required bandwidth
More informationLecture 3: Wireless Physical Layer: Modulation Techniques. Mythili Vutukuru CS 653 Spring 2014 Jan 13, Monday
Lecture 3: Wireless Physical Layer: Modulation Techniques Mythili Vutukuru CS 653 Spring 2014 Jan 13, Monday Modulation We saw a simple example of amplitude modulation in the last lecture Modulation how
More informationDepartment of Electronics and Communication Engineering 1
UNIT I SAMPLING AND QUANTIZATION Pulse Modulation 1. Explain in detail the generation of PWM and PPM signals (16) (M/J 2011) 2. Explain in detail the concept of PWM and PAM (16) (N/D 2012) 3. What is the
More informationWireless Medium Access Control and CDMA-based Communication Lesson 14 CDMA2000
Wireless Medium Access Control and CDMA-based Communication Lesson 14 CDMA2000 1 CDMA2000 400 MHz, 800 MHz, 900 MHz, 1700 MHz, 1800 MHz, 1900 MHz, and 2100 MHz Compatible with the cdmaone standard A set
More informationSPREAD SPECTRUM (SS) SIGNALS FOR DIGITAL COMMUNICATIONS
Dr. Ali Muqaibel SPREAD SPECTRUM (SS) SIGNALS FOR DIGITAL COMMUNICATIONS VERSION 1.1 Dr. Ali Hussein Muqaibel 1 Introduction Narrow band signal (data) In Spread Spectrum, the bandwidth W is much greater
More informationMobile Communications TCS 455
Mobile Communications TCS 455 Dr. Prapun Suksompong prapun@siit.tu.ac.th Lecture 21 1 Office Hours: BKD 3601-7 Tuesday 14:00-16:00 Thursday 9:30-11:30 Announcements Read Chapter 9: 9.1 9.5 HW5 is posted.
More informationThus there are three basic modulation techniques: 1) AMPLITUDE SHIFT KEYING 2) FREQUENCY SHIFT KEYING 3) PHASE SHIFT KEYING
CHAPTER 5 Syllabus 1) Digital modulation formats 2) Coherent binary modulation techniques 3) Coherent Quadrature modulation techniques 4) Non coherent binary modulation techniques. Digital modulation formats:
More informationDownloaded from 1
VII SEMESTER FINAL EXAMINATION-2004 Attempt ALL questions. Q. [1] How does Digital communication System differ from Analog systems? Draw functional block diagram of DCS and explain the significance of
More informationCDMA Tutorial April 29, Michael Souryal April 29, 2006
Michael Souryal April 29, 2006 Common Components Encoding, modulation, spreading Common Features/Functionality Power control, diversity, soft handoff System Particulars cdmaone (IS-95) cdma2000 Sources:
More informationMODULATION AND MULTIPLE ACCESS TECHNIQUES
1 MODULATION AND MULTIPLE ACCESS TECHNIQUES Networks and Communication Department Dr. Marwah Ahmed Outlines 2 Introduction Digital Transmission Digital Modulation Digital Transmission of Analog Signal
More informationALi Linear n-stage t ShiftRegister output tsequence
PN CODE GENERATION (cont d) ALi Linear n-stage t ShiftRegister output tsequence Modulo-2 Adder h hn-1 h hn-2 h h2 h h1 X n-1 X n-2 X 1 X 0 Output Note: hi=1 represents a closed circuit; hi=0 represents
More informationTime division multiplexing The block diagram for TDM is illustrated as shown in the figure
CHAPTER 2 Syllabus: 1) Pulse amplitude modulation 2) TDM 3) Wave form coding techniques 4) PCM 5) Quantization noise and SNR 6) Robust quantization Pulse amplitude modulation In pulse amplitude modulation,
More informationDEPARTMENT OF COMPUTER GCE@Bodi_ SCIENCE GCE@Bodi_ AND ENIGNEERING GCE@Bodi_ GCE@Bodi_ GCE@Bodi_ Analog and Digital Communication GCE@Bodi_ DEPARTMENT OF CsE Subject Name: Analog and Digital Communication
More informationAbout Homework. The rest parts of the course: focus on popular standards like GSM, WCDMA, etc.
About Homework The rest parts of the course: focus on popular standards like GSM, WCDMA, etc. Good news: No complicated mathematics and calculations! Concepts: Understanding and remember! Homework: review
More informationSixth Semester B.E. Degree Examination, May/June 2010 Digital Communication Note: Answer any FIVEfull questions, selecting at least TWO questionsfrom each part. PART-A a. With a block diagram, explain
More informationCDMA Principle and Measurement
CDMA Principle and Measurement Concepts of CDMA CDMA Key Technologies CDMA Air Interface CDMA Measurement Basic Agilent Restricted Page 1 Cellular Access Methods Power Time Power Time FDMA Frequency Power
More informationMultiplexing Module W.tra.2
Multiplexing Module W.tra.2 Dr.M.Y.Wu@CSE Shanghai Jiaotong University Shanghai, China Dr.W.Shu@ECE University of New Mexico Albuquerque, NM, USA 1 Multiplexing W.tra.2-2 Multiplexing shared medium at
More informationAn Overview of the QUALCOMM CDMA Digital Cellular Proposal
An Overview of the QUALCOMM CDMA Digital Cellular Proposal Zeljko Zilic ELE 543S- Course Project Abstract.0 Introduction This paper describes a proposed Code Division Multiple Access (CDMA) digital cellular
More informationPart 3. Multiple Access Methods. p. 1 ELEC6040 Mobile Radio Communications, Dept. of E.E.E., HKU
Part 3. Multiple Access Methods p. 1 ELEC6040 Mobile Radio Communications, Dept. of E.E.E., HKU Review of Multiple Access Methods Aim of multiple access To simultaneously support communications between
More informationPhysical Layer: Modulation, FEC. Wireless Networks: Guevara Noubir. S2001, COM3525 Wireless Networks Lecture 3, 1
Wireless Networks: Physical Layer: Modulation, FEC Guevara Noubir Noubir@ccsneuedu S, COM355 Wireless Networks Lecture 3, Lecture focus Modulation techniques Bit Error Rate Reducing the BER Forward Error
More informationModulation and Coding Tradeoffs
0 Modulation and Coding Tradeoffs Contents 1 1. Design Goals 2. Error Probability Plane 3. Nyquist Minimum Bandwidth 4. Shannon Hartley Capacity Theorem 5. Bandwidth Efficiency Plane 6. Modulation and
More informationChapter 6 Passband Data Transmission
Chapter 6 Passband Data Transmission Passband Data Transmission concerns the Transmission of the Digital Data over the real Passband channel. 6.1 Introduction Categories of digital communications (ASK/PSK/FSK)
More informationCDMA - QUESTIONS & ANSWERS
CDMA - QUESTIONS & ANSWERS http://www.tutorialspoint.com/cdma/questions_and_answers.htm Copyright tutorialspoint.com 1. What is CDMA? CDMA stands for Code Division Multiple Access. It is a wireless technology
More informationUNIT TEST I Digital Communication
Time: 1 Hour Class: T.E. I & II Max. Marks: 30 Q.1) (a) A compact disc (CD) records audio signals digitally by using PCM. Assume the audio signal B.W. to be 15 khz. (I) Find Nyquist rate. (II) If the Nyquist
More informationCommunications Theory and Engineering
Communications Theory and Engineering Master's Degree in Electronic Engineering Sapienza University of Rome A.A. 2018-2019 TDMA, FDMA, CDMA (cont d) and the Capacity of multi-user channels Code Division
More informationPractical issue: Group definition. TSTE17 System Design, CDIO. Quadrature Amplitude Modulation (QAM) Components of a digital communication system
1 2 TSTE17 System Design, CDIO Introduction telecommunication OFDM principle How to combat ISI How to reduce out of band signaling Practical issue: Group definition Project group sign up list will be put
More informationCHAPTER 2. Instructor: Mr. Abhijit Parmar Course: Mobile Computing and Wireless Communication ( )
CHAPTER 2 Instructor: Mr. Abhijit Parmar Course: Mobile Computing and Wireless Communication (2170710) Syllabus Chapter-2.3 Modulation Techniques Reasons for Choosing Encoding Techniques Digital data,
More informationEC 551 Telecommunication System Engineering. Mohamed Khedr
EC 551 Telecommunication System Engineering Mohamed Khedr http://webmail.aast.edu/~khedr 1 Mohamed Khedr., 2008 Syllabus Tentatively Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 Week 8 Week 9 Week
More informationMultirate schemes for multimedia applications in DS/CDMA Systems
Multirate schemes for multimedia applications in DS/CDMA Systems Tony Ottosson and Arne Svensson Dept. of Information Theory, Chalmers University of Technology, S-412 96 Göteborg, Sweden phone: +46 31
More informationWireless Communication Fading Modulation
EC744 Wireless Communication Fall 2008 Mohamed Essam Khedr Department of Electronics and Communications Wireless Communication Fading Modulation Syllabus Tentatively Week 1 Week 2 Week 3 Week 4 Week 5
More informationAmplitude Frequency Phase
Chapter 4 (part 2) Digital Modulation Techniques Chapter 4 (part 2) Overview Digital Modulation techniques (part 2) Bandpass data transmission Amplitude Shift Keying (ASK) Phase Shift Keying (PSK) Frequency
More informationT325 Summary T305 T325 B BLOCK 3 4 PART III T325. Session 11 Block III Part 3 Access & Modulation. Dr. Saatchi, Seyed Mohsen.
T305 T325 B BLOCK 3 4 PART III T325 Summary Session 11 Block III Part 3 Access & Modulation [Type Dr. Saatchi, your address] Seyed Mohsen [Type your phone number] [Type your e-mail address] Prepared by:
More informationISHIK UNIVERSITY Faculty of Science Department of Information Technology Fall Course Name: Wireless Networks
ISHIK UNIVERSITY Faculty of Science Department of Information Technology 2017-2018 Fall Course Name: Wireless Networks Agenda Lecture 4 Multiple Access Techniques: FDMA, TDMA, SDMA and CDMA 1. Frequency
More informationS.D.M COLLEGE OF ENGINEERING AND TECHNOLOGY
VISHVESHWARAIAH TECHNOLOGICAL UNIVERSITY S.D.M COLLEGE OF ENGINEERING AND TECHNOLOGY A seminar report on Orthogonal Frequency Division Multiplexing (OFDM) Submitted by Sandeep Katakol 2SD06CS085 8th semester
More informationWith a lot of material from Rich Nicholls, CTL/RCL and Kurt Sundstrom, of unknown whereabouts
Signal Processing for OFDM Communication Systems Eric Jacobsen Minister of Algorithms, Intel Labs Communication Technology Laboratory/ Radio Communications Laboratory July 29, 2004 With a lot of material
More informationCHETTINAD COLLEGE OF ENGINEERING & TECHNOLOGY NH-67, TRICHY MAIN ROAD, PULIYUR, C.F , KARUR DT.
CHETTINAD COLLEGE OF ENGINEERING & TECHNOLOGY NH-67, TRICHY MAIN ROAD, PULIYUR, C.F. 639 114, KARUR DT. DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING COURSE MATERIAL Subject Name: Analog & Digital
More informationDigital Communication System
Digital Communication System Purpose: communicate information at required rate between geographically separated locations reliably (quality) Important point: rate, quality spectral bandwidth, power requirements
More informationMulti-carrier Modulation and OFDM
3/28/2 Multi-carrier Modulation and OFDM Prof. Luiz DaSilva dasilval@tcd.ie +353 896-366 Multi-carrier systems: basic idea Typical mobile radio channel is a fading channel that is flat or frequency selective
More informationYear : TYEJ Sub: Digital Communication (17535) Assignment No. 1. Introduction of Digital Communication. Question Exam Marks
Assignment 1 Introduction of Digital Communication Sr. Question Exam Marks 1 Draw the block diagram of the basic digital communication system. State the function of each block in detail. W 2015 6 2 State
More informationSpread Spectrum (SS) is a means of transmission in which the signal occupies a
SPREAD-SPECTRUM SPECTRUM TECHNIQUES: A BRIEF OVERVIEW SS: AN OVERVIEW Spread Spectrum (SS) is a means of transmission in which the signal occupies a bandwidth in excess of the minimum necessary to send
More informationOFDMA and MIMO Notes
OFDMA and MIMO Notes EE 442 Spring Semester Lecture 14 Orthogonal Frequency Division Multiplexing (OFDM) is a digital multi-carrier modulation technique extending the concept of single subcarrier modulation
More informationComparative Study of OFDM & MC-CDMA in WiMAX System
IOSR Journal of Electronics and Communication Engineering (IOSR-JECE) e-issn: 2278-2834,p- ISSN: 2278-8735.Volume 9, Issue 1, Ver. IV (Jan. 2014), PP 64-68 Comparative Study of OFDM & MC-CDMA in WiMAX
More informationOrthogonal Frequency Division Multiplexing & Measurement of its Performance
Available Online at www.ijcsmc.com International Journal of Computer Science and Mobile Computing A Monthly Journal of Computer Science and Information Technology IJCSMC, Vol. 5, Issue. 2, February 2016,
More informationChapter 14 MODULATION INTRODUCTION
Chapter 14 MODULATION INTRODUCTION As we have seen in previous three chapters, different types of media need different types of electromagnetic signals to carry information from the source to the destination.
More informationSEN366 Computer Networks
SEN366 Computer Networks Prof. Dr. Hasan Hüseyin BALIK (5 th Week) 5. Signal Encoding Techniques 5.Outline An overview of the basic methods of encoding digital data into a digital signal An overview of
More informationChapter 4. Part 2(a) Digital Modulation Techniques
Chapter 4 Part 2(a) Digital Modulation Techniques Overview Digital Modulation techniques Bandpass data transmission Amplitude Shift Keying (ASK) Phase Shift Keying (PSK) Frequency Shift Keying (FSK) Quadrature
More informationTELE4652 Mobile and Satellite Communication Systems
TELE4652 Mobile and Satellite Communication Systems Lecture 10 IS-95 CDMA A second generation cellular standard, based on CDMA technology, was proposed by Qualcomm in the early 1990s. It was standardised
More informationEC6501 Digital Communication
EC6501 Digital Communication UNIT -1 DIGITAL COMMUNICATION SYSTEMS Digital Communication system 1) Write the advantages and disadvantages of digital communication. [A/M 11] The advantages of digital communication
More informationECE5713 : Advanced Digital Communications
ECE5713 : Advanced Digital Communications Bandpass Modulation MPSK MASK, OOK MFSK 04-May-15 Advanced Digital Communications, Spring-2015, Week-8 1 In-phase and Quadrature (I&Q) Representation Any bandpass
More informationSwedish College of Engineering and Technology Rahim Yar Khan
PRACTICAL WORK BOOK Telecommunication Systems and Applications (TL-424) Name: Roll No.: Batch: Semester: Department: Swedish College of Engineering and Technology Rahim Yar Khan Introduction Telecommunication
More informationECE 476/ECE 501C/CS Wireless Communication Systems Winter Lecture 9: Multiple Access, GSM, and IS-95
ECE 476/ECE 501C/CS 513 - Wireless Communication Systems Winter 2003 Lecture 9: Multiple Access, GSM, and IS-95 Outline: Two other important issues related to multiple access space division with smart
More informationUNIT I Source Coding Systems
SIDDHARTH GROUP OF INSTITUTIONS: PUTTUR Siddharth Nagar, Narayanavanam Road 517583 QUESTION BANK (DESCRIPTIVE) Subject with Code: DC (16EC421) Year & Sem: III-B. Tech & II-Sem Course & Branch: B. Tech
More informationITM 1010 Computer and Communication Technologies
ITM 1010 Computer and Communication Technologies Lecture #14 Part II Introduction to Communication Technologies: Digital Signals: Digital modulation, channel sharing 2003 香港中文大學, 電子工程學系 (Prof. H.K.Tsang)
More informationOrthogonal Frequency Division Multiplexing (OFDM) based Uplink Multiple Access Method over AWGN and Fading Channels
Orthogonal Frequency Division Multiplexing (OFDM) based Uplink Multiple Access Method over AWGN and Fading Channels Prashanth G S 1 1Department of ECE, JNNCE, Shivamogga ---------------------------------------------------------------------***----------------------------------------------------------------------
More informationDetection and Estimation of Signals in Noise. Dr. Robert Schober Department of Electrical and Computer Engineering University of British Columbia
Detection and Estimation of Signals in Noise Dr. Robert Schober Department of Electrical and Computer Engineering University of British Columbia Vancouver, August 24, 2010 2 Contents 1 Basic Elements
More informationSpread Spectrum. Chapter 18. FHSS Frequency Hopping Spread Spectrum DSSS Direct Sequence Spread Spectrum DSSS using CDMA Code Division Multiple Access
Spread Spectrum Chapter 18 FHSS Frequency Hopping Spread Spectrum DSSS Direct Sequence Spread Spectrum DSSS using CDMA Code Division Multiple Access Single Carrier The traditional way Transmitted signal
More informationChapter 1 Acknowledgment:
Chapter 1 Acknowledgment: This material is based on the slides formatted by Dr Sunilkumar S. Manvi and Dr Mahabaleshwar S. Kakkasageri, the authors of the textbook: Wireless and Mobile Networks, concepts
More informationAppendix A. Satellite Signal Processing Elements
Appendix A Satellite Signal Processing Elements This appendix provides an overview of the basic signal processing elements that are present in virtually all traditional communications systems, including
More informationMobile Communication Systems. Part 7- Multiplexing
Mobile Communication Systems Part 7- Multiplexing Professor Z Ghassemlooy Faculty of Engineering and Environment University of Northumbria U.K. http://soe.ac.uk/ocr Contents Multiple Access Multiplexing
More informationUNIT- 7. Frequencies above 30Mhz tend to travel in straight lines they are limited in their propagation by the curvature of the earth.
UNIT- 7 Radio wave propagation and propagation models EM waves below 2Mhz tend to travel as ground waves, These wave tend to follow the curvature of the earth and lose strength rapidly as they travel away
More informationTypical Wireless Communication System
Wireless Communication Fundamentals Part II David Tipper Associate Professor Graduate Telecommunications and Networking Program University it of Pittsburgh Telcom 2700 Slides 3 Typical Wireless Communication
More informationWireless Communication: Concepts, Techniques, and Models. Hongwei Zhang
Wireless Communication: Concepts, Techniques, and Models Hongwei Zhang http://www.cs.wayne.edu/~hzhang Outline Digital communication over radio channels Channel capacity MIMO: diversity and parallel channels
More informationtechniques are means of reducing the bandwidth needed to represent the human voice. In mobile
8 2. LITERATURE SURVEY The available radio spectrum for the wireless radio communication is very limited hence to accommodate maximum number of users the speech is compressed. The speech compression techniques
More informationMultiple Access Schemes
Multiple Access Schemes Dr Yousef Dama Faculty of Engineering and Information Technology An-Najah National University 2016-2017 Why Multiple access schemes Multiple access schemes are used to allow many
More informationCDMA Mobile Radio Networks
- 1 - CDMA Mobile Radio Networks Elvino S. Sousa Department of Electrical and Computer Engineering University of Toronto Canada ECE1543S - Spring 1999 - 2 - CONTENTS Basic principle of direct sequence
More informationCommunication Theory
Communication Theory Adnan Aziz Abstract We review the basic elements of communications systems, our goal being to motivate our study of filter implementation in VLSI. Specifically, we review some basic
More informationSpread Spectrum Basics Spreading Codes IS-95 Features- Transmitter/Receiver Power Control Diversity Techniques RAKE Receiver Soft Handoff
CDMA Mobile Communication & IS-95 1 Outline Spread Spectrum Basics Spreading Codes IS-95 Features- Transmitter/Receiver Power Control Diversity Techniques RAKE Receiver Soft Handoff 2 Spread Spectrum A
More informationEE3723 : Digital Communications
EE3723 : Digital Communications Week 8-9: Bandpass Modulation MPSK MASK, OOK MFSK 04-May-15 Muhammad Ali Jinnah University, Islamabad - Digital Communications - EE3723 1 In-phase and Quadrature (I&Q) Representation
More information<3rd generation CDMA wireless systems>
Page 1 Overview What is 3G? A brief overview of IS95 Key design choices for CDMA 3G systems. Bandwidth Modulation Coding Power Control
More informationDigital Communication System
Digital Communication System Purpose: communicate information at certain rate between geographically separated locations reliably (quality) Important point: rate, quality spectral bandwidth requirement
More informationSpread Spectrum: Definition
Spread Spectrum: Definition refers to the expansion of signal bandwidth, by several orders of magnitude in some cases, which occurs when a key is attached to the communication channel an RF communications
More informationECE 4600 Communication Systems
ECE 4600 Communication Systems Dr. Bradley J. Bazuin Associate Professor Department of Electrical and Computer Engineering College of Engineering and Applied Sciences Course Topics Course Introduction
More informationPage 1. Outline : Wireless Networks Lecture 6: Final Physical Layer. Direct Sequence Spread Spectrum (DSSS) Spread Spectrum
Outline 18-759 : Wireless Networks Lecture 6: Final Physical Layer Peter Steenkiste Dina Papagiannaki Spring Semester 2009 http://www.cs.cmu.edu/~prs/wireless09/ Peter A. Steenkiste 1 RF introduction Modulation
More informationLecture 3 Concepts for the Data Communications and Computer Interconnection
Lecture 3 Concepts for the Data Communications and Computer Interconnection Aim: overview of existing methods and techniques Terms used: -Data entities conveying meaning (of information) -Signals data
More informationOutline / Wireless Networks and Applications Lecture 5: Physical Layer Signal Propagation and Modulation
Outline 18-452/18-750 Wireless Networks and Applications Lecture 5: Physical Layer Signal Propagation and Modulation Peter Steenkiste Carnegie Mellon University Spring Semester 2017 http://www.cs.cmu.edu/~prs/wirelesss17/
More informationChapter 2 Direct-Sequence Systems
Chapter 2 Direct-Sequence Systems A spread-spectrum signal is one with an extra modulation that expands the signal bandwidth greatly beyond what is required by the underlying coded-data modulation. Spread-spectrum
More informationCOMMUNICATION SYSTEMS
COMMUNICATION SYSTEMS 4TH EDITION Simon Hayhin McMaster University JOHN WILEY & SONS, INC. Ш.! [ BACKGROUND AND PREVIEW 1. The Communication Process 1 2. Primary Communication Resources 3 3. Sources of
More informationCSE4214 Digital Communications. Bandpass Modulation and Demodulation/Detection. Bandpass Modulation. Page 1
CSE414 Digital Communications Chapter 4 Bandpass Modulation and Demodulation/Detection Bandpass Modulation Page 1 1 Bandpass Modulation n Baseband transmission is conducted at low frequencies n Passband
More information