# Data Signal Analysis

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 Data Signal Analysis Prof. Alan Kaminsky Department of Computer Science Rochester Institute of Technology Rochester, NY, USA March 2, Signals Signal: A function of time, h(t) Digital signal: A signal with discrete values Example: The bits 1111 as a digital signal Analog signal: A signal with continuous values Example: h(t) = sin2πt Example: h(t) = cos2πt 1

2 Sinusoidal signal: h(t) = a(t) sin(φ(t)) a(t) = amplitude (function of time) φ(t) = phase (function of time) f(t) = 1 dφ(t) 2π dt f(t) = frequency (function of time) t φ(t) = 2π f(τ)dτ +φ() Time in units of seconds (sec) Frequency in units of Hertz (Hz) (1/sec) Phase in units of radians (rad) Example: h(t) = 2sin(1πt+π/4) a(t) = 2 (constant) f(t) = 5 (constant) φ() = π/4 φ(t) = 1πt+π/4 2 Modulation A modulator converts a digital signal to an analog signal, typically a sinusoidal signal A demodulator converts a modulated (analog) signal back to the original unmodulated (digital) signal A modem converts an outgoing digital signal to an outgoing modulated signal, and converts an incoming modulated signal to an incoming digital signal Why? To change the signal s bandwidth so it can be transmitted on a limited-bandwidth communication channel (like a telephone line or a cable TV channel) without too much distortion more on this later How? By using the digital bit stream to vary the sinusoidal signal s amplitude a(t) and/or phase φ(t) 2

3 2.1 Amplitude Modulation (AM) f(t) = f carrier frequency, constant φ(t) = 2πft a(t) = a for a bit, a 1 for a 1 bit Example: Bit stream = 1111, bit rate = 1 bps, f = 4 Hz, a = 1, a 1 = 4 AM Waveform Time (seconds) AM demodulation In each symbol interval, measure the amplitude of the peaks in the waveform Compare the amplitude to a threshold If the amplitude is on one side of the threshold, it s a bit, otherwise it s a 1 bit 3

4 2.2 Frequency Modulation (FM) Also known as frequency shift keying (FSK) a(t) = a constant amplitude f(t) = f for a bit, f 1 for a 1 bit Example: Bit stream = 1111, bit rate = 1 bps, a = 1, f = 3 Hz, f 1 = 4 Hz FM Waveform Time (seconds) The phase ramps up continuously, but with different slopes during different bit intervals The Bell 13 modem standard: An actual telephone modem that used FSK Bit rate = 3 bps Outgoing ( originate ) signal: f = 127 Hz, f 1 = 17 Hz Incoming ( answer ) signal: f = 2225 Hz, f 1 = 225 Hz Mark = bit, mark frequency = f Space = 1 bit, space frequency = f 1 FM demodulation Feed the FM signal through a pair of filters, one tuned to frequency f, the other tuned to frequency f 1 The signal will pass through a filter only if the signal matches the filter s frequency If we get a signal out of the f filter, it s a bit If we get a signal out of the f 1 filter, it s a 1 bit Easy to do with analog circuitry 4

5 2.3 Differential Phase Shift Keying (DPSK) Constant amplitude a Constant frequency f The phase ramps up continuously at a constant slope (frequency) At the start of each bit interval, the phase shifts (increases discontinuously) by an amount φ determined by the bit value: φ =, φ 1 = π Example: Bit stream = 1111, bit rate = 1 bps, a = 1, f = 2 Hz DPSK Waveform Time (seconds) Here is a plot of the phase showing the phase shifts: DPSK demodulation Typically done with an analog circuit called a phase locked loop (PLL) The PLL keeps the phase of an internally-generated sine function in sync to the phase of the incoming signal The PLL generates an output signal which is if the internal sine function s phase is the same as the incoming signal s phase When the incoming signal s phase shifts, the PLL s output signal becomes nonzero until the PLL pulls the internal sine function s phase back in sync with the incoming signal s phase At each bit boundary, look at the PLL s output signal to detect what the phase shift was, then convert that to a or 1 bit 5

6 2.4 Bits Versus Symbols Bit: The original digital value ( or 1) Symbol: The modulated analog waveform Hitherto, each symbol has encoded one bit However, each symbol can encode more than one bit If there are n bits per symbol, the symbol rate (also known as the baud rate) in symbols per second is 1/n times the bit rate in bits per second If there are n bits per symbol, there are 2 n different symbols The Bell 212A modem standard: DPSK with multibit symbols Bit rate = 12 bps n = 2 bits per symbol Symbol rate = 6 symbols per second 4 different symbols Phase shifts: φ = π/2, φ 1 = π, φ 1 =, φ 11 = 3π/2 Outgoing ( originate ) signal: carrier frequency f = 12 Hz Incoming ( answer ) signal: carrier frequency f = 24 Hz Example: Bit stream = 1111, bit rate = 1 bps, symbol rate =.5 symbols per second, a = 1, f = 1 Hz, φ = π/2, φ 1 = π, φ 1 =, φ 11 = 3π/2 2 Bits Per Symbol DPSK Waveform Time (seconds) 6

7 Constellation diagram for a DPSK waveform: Each point represents one symbol A point s distance from the origin gives the symbol s amplitude A point s angle with respect to the positive X axis gives the symbol s phase shift 2.5 Quadrature Amplitude Modulation (QAM) A multibit per symbol waveform that is the sum of an amplitude modulated sine function and an amplitude modulated cosine function at the same, constant carrier frequency f Even bits determine the sine function amplitude s(t): s =, s 1 = a Odd bits determine the cosine function amplitude c(t): c =, c 1 = a h(t) = s(t)sin2πft+c(t)cos2πft Example: Bit stream = 1111, bit rate = 1 bps, symbol rate =.5 symbols per second, a = 1, f = 1 Hz QAM Waveform Time (seconds) 7

8 Constellation diagram for a QAM waveform, showing the symbols amplitudes and absolute phases (instead of phase shifts): You can have QAM with any number of bits per symbol Typically, half of the symbol bits encode the sine amplitude and half of the symbol bits encode the cosine amplitude Example: 2-bits-per-symbol QAM 1 bit encodes sine amplitude, 2 different sine amplitudes 1 bit encodes cosine amplitude, 2 different cosine amplitudes Example: 4-bits-per-symbol QAM 2 bits encode sine amplitude, 4 different sine amplitudes 2 bits encode cosine amplitude, 4 different cosine amplitudes Example: 6-bits-per-symbol QAM 3 bits encode sine amplitude, 8 different sine amplitudes 3 bits encode cosine amplitude, 8 different cosine amplitudes Today s high-speed telephone modems use QAM combined with an error correcting code (trellis code) to achieve a maximum data rate of 33,6 bps (V.34: both channels, V.9: outgoing channel only) Today s cable modems also use QAM, at much higher bit rates than telephone modems QAM demodulation In each symbol interval: Correlate the QAM waveform with a sine function to extract the sine amplitude s Correlate the QAM waveform with a cosine function to extract the cosine amplitude c Convert s and c back to the original bits The correlation of two signals h 1 (t) and h 2 (t): Corr(h 1 (t),h 2 (t)) = h 1 (t)h 2 (t)dt 8

9 Using correlation to extract the sine amplitude from a QAM waveform: Multiply the QAM waveform by a sine function at the same frequency f and integrate over the symbol interval Example: bit rate = 1 bps, symbol rate =.5 symbols per second, symbol interval = 2 seconds, f = 1 Hz QAM waveform in one symbol interval h(t) = ssin2πt+ccos2πt h(t)sin2πtdt = = (ssin2πt+ccos2πt)sin2πtdt ssin 2 2πtdt + ccos2πtsin2πtdt Using the trigonometric identities sin 2 x = (1 cos2x)/2 and cosxsinx = (sin2x)/2: h(t)sin2πtdt = s 2 = s 2 (1 cos4πt)dt + c 2 dt s 2 cos4πtdt + c 2 sin4πtdt sin4πtdt = s 2 2 s 2 + c = s, the sine amplitude 2 Using correlation to extract the cosine amplitude from a QAM waveform: Multiply the QAM waveform by a cosine function at the same frequency f and integrate over the symbol interval Example: bit rate = 1 bps, symbol rate =.5 symbols per second, symbol interval = 2 seconds, f = 1 Hz QAM waveform in one symbol interval h(t) = ssin2πt+ccos2πt h(t)cos2πtdt = = (ssin2πt+ccos2πt)cos2πtdt ssin2πtcos2πtdt + ccos 2 2πtdt Using the trigonometric identities sinxcosx = (sin2x)/2 and cos 2 x = (1+cos2x)/2: h(t)sin2πtdt = s 2 = s 2 sin4πtdt + c 2 sin4πtdt + c 2 (1+cos4πt)dt dt + c 2 cos4πtdt = s 2 + c c = c, the cosine amplitude 2 It is very easy to perform correlation using digital signal processing (DSP) techniques DSP circuits are easy to build out of digital logic gates Digital logic gates are easy to put on integrated circuit chips no nasty analog circuit components needed IC chips are cheap Therefore, QAM modem chips are cheap, which explains the popularity of QAM 9

10 3 Frequency Analysis We ve been studying how modems work, now we ll study why we use modems 3.1 Fourier Synthesis Demonstration: The Sound Synthesizer program (see the Computer Science Course Library) Any periodic signal, like a sound, can be created as the summation of sinusoidal functions: h(t) = a + a j sin(2πjf 1 t+φ j ) j=1 f 1 = fundamental frequency j = harmonic number jf 1 = frequency of the j-th harmonic, a.k.a. the j-th frequency component a j = amplitude of the j-th frequency component φ j = phase of the j-th frequency component a = -frequency component or DC component (DC stands for direct current ) A signal can thus be represented in two equivalent ways: Time domain representation plot h(t) as a function of time Frequency domain representation plot the frequency components amplitudes a j (and phases φ j ) as a function of frequency The latter plot is also called a frequency spectrum The frequency spectrum shows the frequencies where the signal has much power or little power Given the frequency components, it s easy to compute the signal in the time domain Fourier synthesis Given the signal in the time domain, it s trickier to compute the frequency components Fourier analysis 3.2 Fourier Analysis with the Fourier Transform A function of time, h(t), in the time domain can be transformed into a function of frequency, H(f), in the frequency domain using the Fourier transform: H(f) = + h(t)e 2πift dt 1

11 A function of frequency, H(f), in the frequency domain can be transformed back into a function of time, h(t), in the time domain using the inverse Fourier transform: h(t) = + H(f)e 2πift df In practice, you don t compute those integrals analytically Instead, you sample your waveform h(t) to get a time series h j : h j = h(j t),j =,1,2,...N 1 t = sampling interval (seconds) 1/ t = sampling rate (samples per second) N = number of samples Then you transform your time series h j to a frequency series H k (also known as a frequency spectrum) using the discrete Fourier transform (DFT): H k = N 1 j= h j e 2πijk/N,k =,1,2,...N 1 You can transform your frequency series H k back to a time series h j using the inverse discrete Fourier transform: h j = 1 N N 1 k= H k e 2πijk/N,j =,1,2,...N 1 In general, computing the DFT takes O(N 2 ) time If N is a power of 2, then the Fast Fourier Transform (FFT) algorithm can compute the DFT in O(N logn) time The Data Communications and Networks II Course Library includes Java classes for time series, frequency series, and the FFT algorithm 3.3 Interpretation of the Frequency Series The frequency series H k consists of frequency components of the waveform: H = component at f = H 1 = component at f = f H 2 = component at f = 2 f... H k = component at f = k f... H N/2 = component at f = (N/2) f f = 1 N t 11

12 Example: Sampling rate = 8 samples per second, sampling interval t = 125 µsec, N = 512 samples, f = 1/(N t) = 8/512 = Hz, frequency components go from to 4 Hz (The frequency components at indexes greater than N/2 correspond to negative frequencies, but for a real-valued signal the negative frequency components contain the same information as the positive frequency components, so we generally ignore the negative frequency components) The amplitude of the frequency component at frequency k f equals the magnitude of the complex number H k The power of the frequency component at frequency k f equals the square of the magnitude of the complex number H k So a signal s frequency spectrum a plot of H k 2 versus frequency k f shows the frequencies where the signal has much power or little power 3.4 Bandwidth Example of an unmodulated digital signal s frequency spectrum at a bit rate of 3 bps: 1E Power Baseband Signal Frequency Spectrum 1E 1 1E 2 1E 3 1E 4 1E 5 1E Frequency (Hz) A signal s bandwidth is the range of frequencies where most of the energy is located A convenient criterion for determining the bandwidth is to set a threshold, say.1 times the largest frequency component, and include all frequencies from the smallest frequency component above the threshold to the largest frequency component above the threshold The bandwidth of the 3-bps unmodulated digital signal in the above example (threshold =.1) is about to 4 Hz, with most of the power down near Hz 12

13 Example of an unmodulated digital signal s frequency spectrum at a bit rate of 12 bps: 1E Power Baseband Signal Frequency Spectrum 1E 1 1E 2 1E 3 1E 4 1E 5 1E Frequency (Hz) The bandwidth of the 12-bps unmodulated digital signal in the above example (threshold =.1) is about to 16 Hz, with most of the power down near Hz The higher the bit rate, the wider the bandwidth of the signal A communication channel, like a telephone line or a cable TV channel, also has a bandwidth The channel will only transmit energy at frequencies inside its bandwidth Energy at frequencies outside the channel s bandwidth will be attenuated (reduced or eliminated) If you send a signal into a communication channel, the signal s energy outside the channel s bandwith will be lost, and the signal coming out the far end will be distorted If too much signal energy is lost, the received signal will be indecipherable, and communication cannot take place (or will experience too many bit errors) A voice telephone line has (by design) a bandwidth of about 3 Hz to 34 Hz An unmodulated digital signal typically cannot survive transmission through a voice telephone line the signal has too much energy outside the channel s bandwidth, particularly around Hz The solution: Modulating the digital signal shifts the signal s energy to frequencies inside the channel s bandwidth As a result, the modulated signal can be transmitted over a telephone line with little or no distortion, then demodulated back again at the far end The same is true of digital signals transmitted over a cable TV channel, whose bandwidth is about 6 MHz wide THIS, FINALLY, IS WHY WE USE MODEMS! 13

14 3.5 FM Frequency Spectrum Example of a 3-bps FM Bell 13 modem signal s frequency spectrum: 1E Power Outgoing Signal Bell 13 Modem Signal Frequency Spectrum Incoming Signal 1E 1 1E 2 1E 3 1E 4 1E 5 1E Frequency (Hz) Note that the incoming and outgoing signals bandwidths do not overlap At the frequencies where the outgoing signal power is strong, the incoming signal power is much smaller, and vice versa, so the modem has no trouble separating the two signals 3.6 DPSK Frequency Spectrum Example of a 12-bps multibit DPSK Bell 212A modem signal s frequency spectrum: 1E Power Outgoing Signal Bell 212A Modem Signal Frequency Spectrum Incoming Signal 1E 1 1E 2 1E 3 1E 4 1E 5 1E Frequency (Hz) Note the fuller utilization of the channel bandwidth compared to FM Again, at the frequencies where the outgoing signal power is strong, the incoming signal power is much smaller, and vice versa, so the modem has no trouble separating the two signals 14

15 4 Baseband Signals 4.1 Baseband Versus Broadband A broadband communication channel has a bandwidth that goes from some nonzero lower frequency to some nonzero upper frequency Example: Telephone channel 3 Hz to 34 Hz Example: Cable TV channel 6 MHz wide, in the 5 42 MHz range for outgoing (upstream) signals, in the MHz range for incoming (downstream) signals Before transmitting a digital signal on a broadband channel, the digital signal must be modulated to shift the signal s frequencies into the channel s bandwidth A baseband communication channel has a bandwidth that goes from zero frequency (DC) to some upper frequency Example: Ethernet cable A digital signal can be transmitted directly on a baseband channel; no modulation is needed to shift its frequencies However, the digital signal may be encoded for other reasons 4.2 Manchester Encoding 1-Mbps Wired Ethernet Used in 1-Mbps Ethernet LANs (IEEE 82.3) Two voltage levels, L (low,.85 V) and H (high, +.85 V) Each bit is encoded as a pair of voltage levels: = HL, 1 = LH Example: Bit stream = 1111, bit interval =.1 µsec The receiver detects bit boundaries in an Ethernet signal as follows Each Ethernet frame begins with a preamble: 7 bytes of 1111 plus 1 byte of The 1111 bytes, when Manchester encoded, yield a square wave with a transition in the center of each bit interval The receiver synchronizes its clock to these transitions When the receiver sees two consecutive 1 bits, it signals the end of the preamble and the start of the actual frame data 15

16 Since there is a transition at the center of every bit interval, the receiver keep its clock synchronized by detecting these transitions Thus, Manchester encoding yields a self-clocking waveform there is no need for a separate clock signal to synchronize the transmitter s and receiver s bit boundaries Example of a Manchester encoded waveform s frequency spectrum: 1E Power Manchester Encoded Digital Signal Frequency Spectrum 1E 1 1E 2 1E 3 1E 4 1E 5 1E Frequency (MHz) 4.3 Differential Manchester Encoding Used in token ring LANs (IEEE 82.5) Two voltage levels There is a transition at the center of each bit interval For a bit, there is a transition at the beginning of the bit interval (analogous to a phase shift of ) For a 1 bit, there is no transition at the beginning of the bit interval (analogous to a phase shift of π) Example: Bit stream = 1111, bit interval =.1 µsec Like Manchester encoding, differential Manchester encoding yields a self-clocking waveform 16

17 Example of a differential Manchester encoded waveform s frequency spectrum: 1E Power Differential Manchester Encoded Digital Signal Frequency Spectrum 1E 1 1E 2 1E 3 1E 4 1E 5 1E Frequency (MHz) 4.4 MLT-3 Encoding 1-Mbps Wired Ethernet Used in 1-Mbps Ethernet LANs (IEEE 82.3) carried over Category 5 unshielded twisted pair cables (1Base-TX), the most common kind of 1-Mbps Ethernet cabling nowadays There are three steps in encoding a stream of data bits: Step 1. 4B/5B-NRZI Encoding Each group of 4 bits is converted to a group of 5 bits The 5-bit code groups are defined with enough transitions to provide self-clocking, like Manchester encoding But while the Manchester encoded bit rate is 2 times the original bit rate (i.e., 2 Mbps), the 4B/5B-NRZI encoded bit rate is only 1.25 times the original bit rate (i.e., 125 Mbps) This lower encoded bit rate results in a lower bandwidth signal, which can be transmitted over a Category 5 cable without excessive distortion The 4B/5B-NRZI encodings are: Original Encoded Original Encoded

18 Step 2. Scrambling The 4B/5B-NRZI encoded bit stream is exclusive-ored with a pseudorandom bit stream This spreads the signal energy more evenly across the frequency spectrum, making the signal more resistant to noise Step 3. MLT-3 Encoding The 4B/5B-NRZI encoded, scrambled bit stream is further encoded using MLT-3 encoding This shifts most of the signal energy below about 5 MHz, which reduces the amount of energy lost due to radiation out of the cable and reduces interference with adjacent cables There are three voltage levels: V, V, and +V For a bit, there is no transition at the start of the bit interval For a 1 bit, there is a transition at the start of the bit interval; four cases: If the previous transition was V V, transition V V If the previous transition was V V, transition V +V If the previous transition was V +V, transition +V V If the previous transition was +V V, transition V V Example: Original bit stream = B/5B-NRZI encoded bit stream = (Scrambling is omitted in this example) MLT-3 encoded waveform: MLT 3 Signal +V V V Time (nsec) Frequency spectrum: 1E Power MLT 3 Encoded Digital Signal Frequency Spectrum 1E 1 1E 2 1E 3 1E 4 1E 5 1E Frequency (MHz) 18

19 4.5 1-Gbps Wired Ethernet Carried over Category 5 unshielded twisted pair cables (1Base-T), the same cables as 1-Mbps Ethernet Each cable has four pairs of signal wires 1-Mbps Ethernet transmits a 125 million bits per second data stream on one pair and receives a 125 million bits per second data stream on another pair 1-Gbps Ethernet simultaneously transmits and receives a 125 million symbols per second, 2 bits per symbol data stream on all four pairs ( symbols/second/pair) (2 bits/symbol) (4 pairs) = bits/second 1-Mbps Ethernet uses 3-level pulse amplitude modulation (PAM-3) the MLT-3 waveform 1-Gbps Ethernet uses 5-level pulse amplitude modulation (PAM-5) 1-Mbps Ethernet does not do forward error correction 1-Gbps Ethernet does forward error correction by encoding the symbol stream using a trellis code This is needed because PAM-5 is more susceptible to interference than PAM-3 With 5 amplitude levels on each pair and 4 pairs, 5 4 = 625 different symbols can be transmitted To send 8 bits with no redundancy, 256 symbols are needed The trellis code adds redundant information, encoding 8 bits with 512 symbols (2X redundancy) The redundant information lets the decoder correct transmission errors (The remaining 113 symbols are used for control information) 5 Wireless Signals 5.1 Interference With wireless networks, interference with and from signals that are not part of the network becomes a major concern For example, some wireless Ethernet networks use frequencies in the unregulated Industrial/Scientific/Medical (ISM) band of frequencies around 2.4 GHz Unregulated means anyone can transmit signals in this band without needing a license 19

20 So multiple wireless Ethernet networks; other wireless industrial, scientific, or medical devices; Bluetooth devices; and microwave ovens can all be putting out signals in this same band of frequencies at the same time If we don t design the signals carefully, to avoid interfering with other signals, and to tolerate interference from other signals, we will get chaos and nothing will work This is not so much of a problem with wired networks because the cabling is designed to minimize interference, so the signal doesn t have to This becomes more of a problem with high data rate wired networks For example, interference considerations drove the design of the 1-Mbps Ethernet signal (MLT-3 encoding) 5.2 Wireless Ethernet Standards Data Rate Frequency Encoding Modulation Standard (Mbps) Band (GHz) Method Method FHSS 1-bit-per-symbol FM (1997) FHSS 2-bit-per-symbol FM DSSS 1-bit-per-symbol DPSK DSSS 2-bit-per-symbol DPSK 82.11b DSSS CCK (1999) DSSS CCK 82.11a 6 5 OFDM 1-bit-per-symbol DPSK (1999) 9 5 OFDM 1-bit-per-symbol DPSK 12 5 OFDM 2-bit-per-symbol DPSK 18 5 OFDM 2-bit-per-symbol DPSK 24 5 OFDM 4-bit-per-symbol QAM 36 5 OFDM 4-bit-per-symbol QAM 48 5 OFDM 6-bit-per-symbol QAM 54 5 OFDM 6-bit-per-symbol QAM 82.11g Various Various (23) 82.11n , 5 OFDM Various (29) , 5 OFDM Various 82.11ad up to OFDM Various (212) 82.11ac up to OFDM Various (214) 2

21 FHSS = Frequency Hopping Spread Spectrum DSSS = Direct Sequence Spread Spectrum OFDM = Orthogonal Frequency Division Multiplexing FM = Frequency Modulation DPSK = Differential Phase Shift Keying CCK = Complementary Code Keying QAM = Quadrature Amplitude Modulation 5.3 The Mbps DSSS Signal The signal uses one of the following carrier frequencies (in the U.S.): Channel Frequency GHz GHz GHz GHz GHz GHz GHz GHz GHz GHz GHz The 1-Mbps bit stream modulates the carrier using DPSK with these phase shifts: φ =, φ 1 = π Thus, there are 1 million symbols per second The DPSK-modulated signal is multiplied by a chipping sequence, a.k.a. a spreading sequence, a.k.a. a pseudonoise (PN) sequence Each chip is +1 or 1 The chipping sequence consists of the following 11 chips continually repeated at a chip rate of 11 million chips per second: +1, 1,+1,+1, 1,+1,+1,+1, 1, 1, 1 Thus, each modulated symbol is multiplied by the chipping sequence 21

23 5.4 The Mbps DSSS Signal The 2-Mbps signal uses the same carrier frequencies as the 1-Mbps signal The 2-Mbps bit stream modulates the carrier using two-bits-per-symbol DPSK with these phase shifts: φ =, φ 1 = π/2, φ 1 = 3π/2, φ 11 = π Thus, there are 1 million symbols per second The 1 million symbols per second DPSK-modulated signal is multiplied by the same 11 million chips per second chipping sequence: +1, 1,+1,+1, 1,+1,+1,+1, 1, 1, 1 Thus, each modulated symbol is multiplied by the chipping sequence 23

### Outlines. LECTURE 3: Wireless Transmission Technologies. Wireless Transmission on Unguided Media

LECTURE 3: Wireless Transmission Technologies CIS 472 Wireless Communications and Networks Winter 2016 Instructor: Dr. Song Xing Outlines Wireless Data Transmission Modulation Spread Spectrum Department

### Digital vs. Analog Transmission

Digital vs. Analog Transmission Two forms of transmission: digital transmission: data transmission using square waves analog transmission: data transmission using all other waves Four possibilities to

### ANALOG VS DIGITAL. Copyright 1998, Professor John T.Gorgone

ANALOG VS DIGITAL 1 BASICS OF DATA COMMUNICATIONS Data Transport System Analog Data Digital Data The transport of data through a telecommunications network can be classified into two overall transport

### Signal Encoding Techniques

Signal Encoding Techniques Guevara Noubir noubir@ccs.neu.edu 1 Reasons for Choosing Encoding Techniques Digital data, digital signal Equipment less complex and expensive than digital-to-analog modulation

### Physical Layer Part 2. Data Encoding Techniques. Networks: Data Encoding 1

Physical Layer Part 2 Data Encoding Techniques Networks: Data Encoding 1 Analog and Digital Transmissions Figure 2-23.The use of both analog and digital transmissions for a computer to computer call. Conversion

### Data Communications Prof. Ajit Pal Department of Computer Science & Engineering Indian Institute of Technology, Kharagpur Lecture # 03 Data and Signal

(Refer Slide Time: 00:01:23) Data Communications Prof. Ajit Pal Department of Computer Science & Engineering Indian Institute of Technology, Kharagpur Lecture # 03 Data and Signal Hello viewers welcome

### CS263: Wireless Communications and Sensor Networks

CS263: Wireless Communications and Sensor Networks Matt Welsh Lecture 2: RF Basics and Signal Encoding September 22, 2005 2005 Matt Welsh Harvard University 1 Today's Lecture Basics of wireless communications

### Analog and Digital Signals, Time and Frequency Representation of Signals

1 Analog and Digital Signals, Time and Frequency Representation of Signals Required reading: Garcia 3.1, 3.2 CSE 3213, Fall 2010 Instructor: N. Vlajic 2 Data vs. Signal Analog vs. Digital Analog Signals

### Signal Encoding Techniques

CSE 3461/5461: Introduction to Computer Networking & Internet Technologies Signal Encoding Techniques Presentation C Study: 5.1, 5.2 (pages 151-155 only), 5.3, 5.4 (Figure 5.24 only) Gojko Babić 09-04-2012

### Public Switched Telephone System

Public Switched Telephone System Structure of the Telephone System The Local Loop: Modems, ADSL Structure of the Telephone System (a) Fully-interconnected network. (b) Centralized switch. (c) Two-level

### Digital Modulation. David Tipper. Department of Information Science and Telecommunications University of Pittsburgh. Typical Communication System

Digital Modulation David Tipper Associate Professor Department of Information Science and Telecommunications University of Pittsburgh http://www.tele.pitt.edu/tipper.html Typical Communication System Source

### Objectives. Lecture 4. How do computers communicate? How do computers communicate? Local asynchronous communication. How do computers communicate?

Lecture 4 Continuation of transmission basics Chapter 3, pages 75-96 Dave Novak School of Business University of Vermont Objectives Line coding Modulation AM, FM, Phase Shift Multiplexing FDM, TDM, WDM

### Implementation of Digital Signal Processing: Some Background on GFSK Modulation

Implementation of Digital Signal Processing: Some Background on GFSK Modulation Sabih H. Gerez University of Twente, Department of Electrical Engineering s.h.gerez@utwente.nl Version 4 (February 7, 2013)

### EECC694 - Shaaban. Transmission Channel

The Physical Layer: Data Transmission Basics Encode data as energy at the data (information) source and transmit the encoded energy using transmitter hardware: Possible Energy Forms: Electrical, light,

### Mobile Communications Chapter 2: Wireless Transmission

Mobile Communications Chapter 2: Wireless Transmission Frequencies Signals Antennas Signal propagation Multiplexing Spread spectrum Modulation Cellular systems Prof. Dr.-Ing. Jochen Schiller, http://www.jochenschiller.de/

### Lecture 3: Signaling and Clock Recovery. CSE 123: Computer Networks Stefan Savage

Lecture 3: Signaling and Clock Recovery CSE 123: Computer Networks Stefan Savage Last time Protocols and layering Application Presentation Session Transport Network Datalink Physical Application Transport

### Analog vs. Digital Transmission

Analog vs. Digital Transmission Compare at two levels: 1. Data continuous (audio) vs. discrete (text) 2. Signaling continuously varying electromagnetic wave vs. sequence of voltage pulses. Also Transmission

### Chapter 3: Spread Spectrum Technologies

Chapter 3: Spread Spectrum Technologies Overview Comprehend the differences between, and explain the different types of spread spectrum technologies and how they relate to the IEEE 802.11 standard's PHY

### (Refer Slide Time: 2:10)

Data Communications Prof. A. Pal Department of Computer Science & Engineering Indian Institute of Technology, Kharagpur Lecture-12 Multiplexer Applications-1 Hello and welcome to today s lecture on multiplexer

### Department of Electrical and Computer Engineering Ben-Gurion University of the Negev. LAB 1 - Introduction to USRP

Department of Electrical and Computer Engineering Ben-Gurion University of the Negev LAB 1 - Introduction to USRP - 1-1 Introduction In this lab you will use software reconfigurable RF hardware from National

### A Primer on Digital Modulation

A Primer on Digital Modulation By Bertrand Zauhar, VE2ZAZ http://ve2zaz.net August 2013 In this Presentation Modulation Fundamentals Real Life Communications Design Constraints Digital Modulation (DM)

### EE4512 Analog and Digital Communications Chapter 5. Chapter 5 Digital Bandpass Modulation and Demodulation Techniques

Chapter 5 Digital Bandpass Modulation and Demodulation Techniques Chapter 5 Digital Bandpass Modulation and Demodulation Techniques Binary Amplitude Shift Keying Pages 212-219 219 The analytical signal

### Using GNU Radio Companion: Tutorial 4. Using Complex Signals and Receiving SSB

Using GNU Radio Companion: Tutorial 4. Using Complex Signals and Receiving SSB This tutorial is a guide to receiving SSB signals. It will also illustrate some of the properties of complex (analytic) signals

### Team 8 Michael Price Brandon Briegel Jerrod Kempf Matt Henry Arber Nicaj. RF Communication

Team 8 Michael Price Brandon Briegel Jerrod Kempf Matt Henry Arber Nicaj RF Communication Discussion Topics Electromagnetic Spectrum Hardware Modulation/Demodulation Noise Bluetooth Introduction What is

### Appendix D Digital Modulation and GMSK

D1 Appendix D Digital Modulation and GMSK A brief introduction to digital modulation schemes is given, showing the logical development of GMSK from simpler schemes. GMSK is of interest since it is used

### Application Note. Bluetooth test capability on 2026B.

Application Note Bluetooth test capability on 2026B The integration of Bluetooth interfaces into cellular mobile products brings new challenging test issues in the design and manufacture stages. This application

### TCOM 370 NOTES 99-7 DIGITAL DATA TRANSMISSION

TCOM 370 NOTES 99-7 DIGITAL DATA TRANSMISSION Synchronization and Related Topics DIGITAL DATA TRANSMISSION (BASEBAND) "Data" in general is a sequence of binary digits. It may represent a sequence of alphanumeric

### Voice---is analog in character and moves in the form of waves. 3-important wave-characteristics:

Voice Transmission --Basic Concepts-- Voice---is analog in character and moves in the form of waves. 3-important wave-characteristics: Amplitude Frequency Phase Voice Digitization in the POTS Traditional

### 4 Digital Video Signal According to ITU-BT.R.601 (CCIR 601) 43

Table of Contents 1 Introduction 1 2 Analog Television 7 3 The MPEG Data Stream 11 3.1 The Packetized Elementary Stream (PES) 13 3.2 The MPEG-2 Transport Stream Packet.. 17 3.3 Information for the Receiver

### Data Transmission. Data Communications Model. CSE 3461 / 5461: Computer Networking & Internet Technologies. Presentation B

CSE 3461 / 5461: Computer Networking & Internet Technologies Data Transmission Presentation B Kannan Srinivasan 08/30/2012 Data Communications Model Figure 1.2 Studying Assignment: 3.1-3.4, 4.1 Presentation

### RF Measurements Using a Modular Digitizer

RF Measurements Using a Modular Digitizer Modern modular digitizers, like the Spectrum M4i series PCIe digitizers, offer greater bandwidth and higher resolution at any given bandwidth than ever before.

### Timing Errors and Jitter

Timing Errors and Jitter Background Mike Story In a sampled (digital) system, samples have to be accurate in level and time. The digital system uses the two bits of information the signal was this big

### Original Lecture Notes developed by

Introduction to ADSL Modems Original Lecture Notes developed by Prof. Brian L. Evans Dept. of Electrical and Comp. Eng. The University of Texas at Austin http://signal.ece.utexas.edu Outline Broadband

### The front end of the receiver performs the frequency translation, channel selection and amplification of the signal.

Many receivers must be capable of handling a very wide range of signal powers at the input while still producing the correct output. This must be done in the presence of noise and interference which occasionally

### Trigonometric functions and sound

Trigonometric functions and sound The sounds we hear are caused by vibrations that send pressure waves through the air. Our ears respond to these pressure waves and signal the brain about their amplitude

### What s The Difference Between Bit Rate And Baud Rate?

What s The Difference Between Bit Rate And Baud Rate? Apr. 27, 2012 Lou Frenzel Electronic Design Serial-data speed is usually stated in terms of bit rate. However, another oftquoted measure of speed is

### MODULATION Systems (part 1)

Technologies and Services on Digital Broadcasting (8) MODULATION Systems (part ) "Technologies and Services of Digital Broadcasting" (in Japanese, ISBN4-339-62-2) is published by CORONA publishing co.,

### Chap#5 (Data communication)

Chap#5 (Data communication) Q#1: Define analog transmission. Normally, analog transmission refers to the transmission of analog signals using a band-pass channel. Baseband digital or analog signals are

### Fast Fourier Transforms and Power Spectra in LabVIEW

Application Note 4 Introduction Fast Fourier Transforms and Power Spectra in LabVIEW K. Fahy, E. Pérez Ph.D. The Fourier transform is one of the most powerful signal analysis tools, applicable to a wide

### CS423: Lectures 2-4, Physical Layer. George Varghese. April 16, 2008

CS423: Lectures 2-4, Physical Layer George Varghese April 16, 2008 What does the Physical Layer Do? bits SENDER PHYSICAL LAYER RECEIVER 1 RECEIVER 1 RECEIVER 1 A possibly faulty, single-hop, bit pipe that

### Frequency Hopping Spread Spectrum (FHSS) vs. Direct Sequence Spread Spectrum (DSSS) in Broadband Wireless Access (BWA) and Wireless LAN (WLAN)

FHSS vs. DSSS page 1 of 16 Frequency Hopping Spread Spectrum (FHSS) vs. Direct Sequence Spread Spectrum (DSSS) in Broadband Wireless Access (BWA) and Wireless LAN (WLAN) by Sorin M. SCHWARTZ Scope In 1997

### Clock Recovery in Serial-Data Systems Ransom Stephens, Ph.D.

Clock Recovery in Serial-Data Systems Ransom Stephens, Ph.D. Abstract: The definition of a bit period, or unit interval, is much more complicated than it looks. If it were just the reciprocal of the data

### ISM Band Device Test

ISM Band Device Test Agenda ISM Band Background Modulation and Parametric Testing of ISM Band ISM Device Test Demonstration ZigBee ZigBee Demonstration Industrial, Scientific and Medical Radio Band Originally

### INTRODUCTION TO COMMUNICATION SYSTEMS AND TRANSMISSION MEDIA

COMM.ENG INTRODUCTION TO COMMUNICATION SYSTEMS AND TRANSMISSION MEDIA 9/6/2014 LECTURES 1 Objectives To give a background on Communication system components and channels (media) A distinction between analogue

### Curve Fitting. Next: Numerical Differentiation and Integration Up: Numerical Analysis for Chemical Previous: Optimization.

Next: Numerical Differentiation and Integration Up: Numerical Analysis for Chemical Previous: Optimization Subsections Least-Squares Regression Linear Regression General Linear Least-Squares Nonlinear

### T = 1 f. Phase. Measure of relative position in time within a single period of a signal For a periodic signal f(t), phase is fractional part t p

Data Transmission Concepts and terminology Transmission terminology Transmission from transmitter to receiver goes over some transmission medium using electromagnetic waves Guided media. Waves are guided

### CDMA TECHNOLOGY. Brief Working of CDMA

CDMA TECHNOLOGY History of CDMA The Cellular Challenge The world's first cellular networks were introduced in the early 1980s, using analog radio transmission technologies such as AMPS (Advanced Mobile

### Computers Are Your Future. 2006 Prentice-Hall, Inc.

Computers Are Your Future 2006 Prentice-Hall, Inc. Computers Are Your Future Chapter 3 Wired and Wireless Communication 2006 Prentice-Hall, Inc Slide 2 What You Will Learn... ü The definition of bandwidth

### Next Generation of High Speed. Modems8

Next Generation of High Speed Modems High Speed Modems. 1 Traditional Modems Assume both ends have Analog connection Analog signals are converted to Digital and back again. Limits transmission speed to

### Vector Signal Analyzer FSQ-K70

Product brochure Version 02.00 Vector Signal Analyzer FSQ-K70 July 2004 Universal demodulation, analysis and documentation of digital radio signals For all major mobile radio communication standards: GSM

### Lecture 1: Introduction

Mobile Data Networks Lecturer: Victor O.K. Li EEE Department Room: CYC601D Tel.: 857 845 Email: vli@eee.hku.hk Course home page: http://www.eee.hku.hk/courses.msc/ 1 Lecture 1: Introduction Mobile data

### Chapter 6 Bandwidth Utilization: Multiplexing and Spreading 6.1

Chapter 6 Bandwidth Utilization: Multiplexing and Spreading 6.1 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Note Bandwidth utilization is the wise use of

### Computer Networks and Internets, 5e Chapter 6 Information Sources and Signals. Introduction

Computer Networks and Internets, 5e Chapter 6 Information Sources and Signals Modified from the lecture slides of Lami Kaya (LKaya@ieee.org) for use CECS 474, Fall 2008. 2009 Pearson Education Inc., Upper

### HD Radio FM Transmission System Specifications

HD Radio FM Transmission System Specifications Rev. E January 30, 2008 Doc. No. SY_SSS_1026s TRADEMARKS The ibiquity Digital logo and ibiquity Digital are registered trademarks of ibiquity Digital Corporation.

### CHAPTER 8 MULTIPLEXING

CHAPTER MULTIPLEXING 3 ANSWERS TO QUESTIONS.1 Multiplexing is cost-effective because the higher the data rate, the more cost-effective the transmission facility.. Interference is avoided under frequency

### 16.36 Communication Systems Engineering

MIT OpenCourseWare http://ocw.mit.edu 16.36 Communication Systems Engineering Spring 2009 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. 16.36: Communication

### Frequency Hopping Spread Spectrum PHY of the 802.11 Wireless LAN Standard. Why Frequency Hopping?

Frequency Hopping Spread Spectrum PHY of the 802.11 Wireless LAN Standard Presentation to IEEE 802 March 11, 1996 Naftali Chayat BreezeCom 1 Why Frequency Hopping? Frequency Hopping is one of the variants

### Digital Fundamentals

Digital Fundamentals Tenth Edition Floyd Chapter 1 2009 Pearson Education, Upper 2008 Pearson Saddle River, Education NJ 07458. All Rights Reserved Analog Quantities Most natural quantities that we see

### BPSK - BINARY PHASE SHIFT KEYING

BPSK - BINARY PHASE SHIFT KEYING PREPARATION... 70 generation of BPSK... 70 bandlimiting... 71 BPSK demodulation... 72 phase ambiguity...72 EXPERIMENT... 73 the BPSK generator... 73 BPSK demodulator...

### Digital Signal Processing ADC and DAC

Digital Signal Processing ADC and DAC Moslem Amiri, Václav Přenosil Masaryk University Resource: The Scientist and Engineer's Guide to Digital Signal Processing (www.dspguide.com) By Steven W. Smith Quantization

### Protocolo IEEE 802.15.4. Sergio Scaglia SASE 2012 - Agosto 2012

Protocolo IEEE 802.15.4 SASE 2012 - Agosto 2012 IEEE 802.15.4 standard Agenda Physical Layer for Wireless Overview MAC Layer for Wireless - Overview IEEE 802.15.4 Protocol Overview Hardware implementation

### The Calculation of G rms

The Calculation of G rms QualMark Corp. Neill Doertenbach The metric of G rms is typically used to specify and compare the energy in repetitive shock vibration systems. However, the method of arriving

### GSM/EDGE Output RF Spectrum on the V93000 Joe Kelly and Max Seminario, Verigy

GSM/EDGE Output RF Spectrum on the V93000 Joe Kelly and Max Seminario, Verigy Introduction A key transmitter measurement for GSM and EDGE is the Output RF Spectrum, or ORFS. The basis of this measurement

### The Boonton USB Peak Power Sensor, Wi-Fi ac Signals and the ETSI EN Standard

Application Note The Boonton 55006 USB Peak Power Sensor, Wi-Fi 802.11ac Signals and the ETSI EN 300 328 Standard Stephen Shaw Applications Engineer, Boonton Electronics Abstract This application note

### 1. (Ungraded) A noiseless 2-kHz channel is sampled every 5 ms. What is the maximum data rate?

Homework 2 Solution Guidelines CSC 401, Fall, 2011 1. (Ungraded) A noiseless 2-kHz channel is sampled every 5 ms. What is the maximum data rate? 1. In this problem, the channel being sampled gives us the

### Convolution, Correlation, & Fourier Transforms. James R. Graham 10/25/2005

Convolution, Correlation, & Fourier Transforms James R. Graham 10/25/2005 Introduction A large class of signal processing techniques fall under the category of Fourier transform methods These methods fall

### Computer Networks I. Transmission Media

Version 2/21/11 Computer Networks I application transport network Transmission Media link physical Fernando.Rincon@uclm.es Computer Networks I 2 Outline Some informal definitions Guide Media Unguided Media:

### Wireless Medical Telemetry Laboratory

Wireless Medical Telemetry Laboratory 0 Introduction The development of wireless medical telemetry has become an increasingly popular application in recent years. As the elderly population continues to

### QAM and QPSK: Aim: Introduction:

QAM 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

### Errata Introduction to Wireless Systems P. Mohana Shankar. Page numbers are shown in blue Corrections are shown in red.

Errata Introduction to Wireless Systems P. Mohana Shankar Page numbers are shown in blue Corrections are shown in red February 25 Page 11 below Figure 2.4 The power detected by a typical receiver is shown

### Wireless Local Area Networking For Device Monitoring

Wireless Local Area Networking For Device Monitoring by Colin Goldsmith Supervised By Professor Wendi Heinzelman A thesis submitted in partial fulfillment of the Requirements for the Degree of Masters

### :-------------------------------------------------------Instructor---------------------

Yarmouk University Hijjawi Faculty for Engineering Technology Computer Engineering Department CPE-462 Digital Data Communications Final Exam: A Date: 20/05/09 Student Name :-------------------------------------------------------Instructor---------------------

### Implementing Digital Wireless Systems. And an FCC update

Implementing Digital Wireless Systems And an FCC update Spectrum Repacking Here We Go Again: The FCC is reallocating 600 MHz Frequencies for Wireless Mics 30-45 MHz (8-m HF) 174-250 MHz (VHF) 450-960 MHz

LABORATORY EXPERIMENT Infrared Transmitter/Receiver (Note to Teaching Assistant: The week before this experiment is performed, place students into groups of two and assign each group a specific frequency

### Advantages of High Resolution in High Bandwidth Digitizers

Advantages of High Resolution in High Bandwidth Digitizers Two of the key specifications of digitizers are bandwidth and amplitude resolution. These specifications are not independent - with increasing

### The Effect of Network Cabling on Bit Error Rate Performance. By Paul Kish NORDX/CDT

The Effect of Network Cabling on Bit Error Rate Performance By Paul Kish NORDX/CDT Table of Contents Introduction... 2 Probability of Causing Errors... 3 Noise Sources Contributing to Errors... 4 Bit Error

### Bonus Web Chapter. Radio. Frequency

Bonus Web Chapter 3 Radio Frequency 1 2 Hacking Exposed Wireless: Wireless Security Secrets & Solutions This Bonus Web Chapter provides the average reader with a crash course in the basics of radio frequency

### Modulation methods. S-72. 333 Physical layer methods in wireless communication systems. Sylvain Ranvier / Radio Laboratory / TKK 16 November 2004

Modulation methods S-72. 333 Physical layer methods in wireless communication systems Sylvain Ranvier / Radio Laboratory / TKK 16 November 2004 sylvain.ranvier@hut.fi SMARAD / Radio Laboratory 1 Line out

### QAM Demodulation. Performance Conclusion. o o o o o. (Nyquist shaping, Clock & Carrier Recovery, AGC, Adaptive Equaliser) o o. Wireless Communications

0 QAM Demodulation o o o o o Application area What is QAM? What are QAM Demodulation Functions? General block diagram of QAM demodulator Explanation of the main function (Nyquist shaping, Clock & Carrier

### Making 802.11G Transmitter Measurements

Making 802.11G Transmitter Measurements Application Note 1380-4 802.11g is the latest standard in wireless computer networking. It follows on the developments of 802.11a and 802.11b, combining the speed

### CS647: Advanced Topics in Wireless Networks Basics of Wireless Transmission

CS647: Advanced Topics in Wireless Networks Basics of Wireless Transmission CS 647 2.1 Outline Frequencies Signals Antennas Signal propagation Multiplexing Spread spectrum Modulation CS 647 2.2 Types of

### The Phase Modulator In NBFM Voice Communication Systems

The Phase Modulator In NBFM Voice Communication Systems Virgil Leenerts 8 March 5 The phase modulator has been a point of discussion as to why it is used and not a frequency modulator in what are called

### Module 5 Local Area Networks

Module 5 Local Area Networks Lesson 18 Token Passing LANs OBJECTIVE General The lesson will discuss the Token Passing LANs Specific The focus areas of this lesson are: 1. Idea of Token passing LANs 2.

AM Receiver Prelab In this experiment you will use what you learned in your previous lab sessions to make an AM receiver circuit. You will construct an envelope detector AM receiver. P1) Introduction One

### Silicon Laboratories, Inc. Rev 1.0 1

Clock Division with Jitter and Phase Noise Measurements Introduction As clock speeds and communication channels run at ever higher frequencies, accurate jitter and phase noise measurements become more

### PCM Encoding and Decoding:

PCM Encoding and Decoding: Aim: Introduction to PCM encoding and decoding. Introduction: PCM Encoding: The input to the PCM ENCODER module is an analog message. This must be constrained to a defined bandwidth

Chapter 3 ADSL / VDSL Technologies Both ADSL and VDSL are designed to operate on a subscriber s existing twisted copper access pair terminating at a Local Exchange Building (LEX) in conjunction with the

### Lezione 6 Communications Blockset

Corso di Tecniche CAD per le Telecomunicazioni A.A. 2007-2008 Lezione 6 Communications Blockset Ing. Marco GALEAZZI 1 What Is Communications Blockset? Communications Blockset extends Simulink with a comprehensive

### Sampling Theorem Notes. Recall: That a time sampled signal is like taking a snap shot or picture of signal periodically.

Sampling Theorem We will show that a band limited signal can be reconstructed exactly from its discrete time samples. Recall: That a time sampled signal is like taking a snap shot or picture of signal

### Telecommunication systems. Telecommunication system

Telecommunication systems Telecommunication system The public-switched telephone network (PSTN) was originally analogue, but during the last 30 years it has been transformed into an almost fully digital

### University of Manchester School of Computer Science CS3282: Digital Communications '06 Section 9: Multi-level digital modulation & demodulation.

CS3282 Digital Comms 9.1 2 May 06 / BMGC University of Manchester School of Computer Science CS3282: Digital Communications '06 Section 9: Multi-level digital modulation & demodulation. 9.1. ntroduction:

### DT3: RF On/Off Remote Control Technology. Rodney Singleton Joe Larsen Luis Garcia Rafael Ocampo Mike Moulton Eric Hatch

DT3: RF On/Off Remote Control Technology Rodney Singleton Joe Larsen Luis Garcia Rafael Ocampo Mike Moulton Eric Hatch Agenda Radio Frequency Overview Frequency Selection Signals Methods Modulation Methods

### Physical Layer, Part 2 Digital Transmissions and Multiplexing

Physical Layer, Part 2 Digital Transmissions and Multiplexing These slides are created by Dr. Yih Huang of George Mason University. Students registered in Dr. Huang's courses at GMU can make a single machine-readable

### The Effective Number of Bits (ENOB) of my R&S Digital Oscilloscope Technical Paper

The Effective Number of Bits (ENOB) of my R&S Digital Oscilloscope Technical Paper Products: R&S RTO1012 R&S RTO1014 R&S RTO1022 R&S RTO1024 This technical paper provides an introduction to the signal

### TC-3000C Bluetooth Tester

TC-3000C Bluetooth Tester Product Overview TC-3000C Bluetooth Tester Data Sheet TC-3000C Bluetooth Tester is able to analyze the data of each packet that is transmitted to the upper application protocol

### The influence of Wi-Fi on the operation of Bluetooth based wireless sensor networks in the Internet of Things

Faculty of Electrical Engineering, Mathematics & Computer Science The influence of Wi-Fi on the operation of Bluetooth based wireless sensor networks in the Internet of Things Jermain C. Horsman B.Sc.

### SECTION 2 TECHNICAL DESCRIPTION OF BPL SYSTEMS

SECTION 2 TECHNICAL DESCRIPTION OF SYSTEMS 2.1 INTRODUCTION Access equipment consists of injectors (also known as concentrators), repeaters, and extractors. injectors are tied to the backbone via fiber