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Analog data is carried by an alternating current. If we were tographically represent alternating current, it would appear as awave, with voltage bouncing above and below the zero level. Thereare three factors to consider: frequency, amplitude, and phase.
In psk we need to keep track of the change in the phase of the receiving signal, in fsk we can using only 2 frequencies Read More.
Frequency is the rate at which the current alternates above andbelow the zero current level. When the current rises above zero,dips below zero and then returns to zero, we say the current hascompleted one 'cycle'. The name applied to the number of cycles persecond is Hertz (Hz). Therefore, if there are 500 cycles per secondfor an analog signal, we say the frequency is 500 Hertz (500Hz).
Amplitude would be viewed as the height (peak) and the depth(trough) of the graphic wave. As analog data travels over distance,the amplitude of the wave decreases. This characteristic is called'attenuation'. The amplitude of analog waves is measured in watts,amps or volts. The measurement decibel is often used todescribe the power of a signal.
Finally, phase describes the difference in the start of thecycle of one signal to the start of the cycle of another. Onesignal acts as a reference signal, the other signal is the phasedsignal. The level of non-synchronization is measured indegrees. If a signal is 180º out of phase, it means that asthe reference signal reaches zero voltage following a peak, thephased signal begins. Thus as the reference signal is peaking, thephased signal is (for lack of a better term) troughing. The figurebelow illustrates this more clearly.
Phasing is the result of creating a signal out of sync with areference signal.Altering the frequency, amplitude or phase ofa signal is called modulation
.ASK:AM radio is produced by taking a basicsignal (radio wave) and modulating its amplitude according toanother signal (i.e. voice and music). AM stands for AmplitudeModulation. We may use the same technology for carrying computerdata as well. For digital data, it's called Amplitude-ShiftKeying (ASK).
Figure 5.2: Amplitude Modulation can be used to encode datain analog signals.
FSK: FM radio is produced by taking a basicsignal (radio wave) and modulating its frequency according toanother signal (i.e. music and voice). In this case, FM is anacronym for Frequency Modulation. In the digital data realm, thesame technology can be applied using Frequency-Shift Keying(FSK). Fig illustrates a couple of examples.
Figure 5.3: Frequency Modulation may be used to encode datainto an analog signal as well.
PSK:
Figure 5.4: Phase Modulation can be used to encode data in ananalog signal. The amplitude is varied in sometechnologies.
In analyzing methods for carrying digital data, Amplitude-ShiftKeying is fairly easy to accomplish. On the other hand, any kind ofamplitude modulated signal is very susceptible to outsideinterference. Therefore, ASK is not really suitable fortransmission over long distances.
Just as FM radio is not generally affected by weather, neitherare FSK transmissions. In spite of this, Frequency-Shift Modulationis seldom used for transmission over high-speed lines as thetechnology does not allow as many bits per second throughput as PSKdoes.
Phase-Shift Keying technology is what is utilized by most highspeed modern modems. It allows four different phases (in degrees)to encode data. The result is a potential for 600 phase shifts persecond. Each phase shift represents a certain combination of 2 bits(i.e. 00 01 10 or 11). It then logically follows that since twobits are transmitted per phase shift and there are 600 phase shiftsper second.
PSK is very resistant to external interference as it enjoys mostof the same characteristics that FM or FSK devices do. The signalsencoded using PSK may be used for synchronization purposes as wellfor the sender and receiver.
Compear fsk and psk?
Advantages of psk over fsk and ask?
in psk we need to keep track of the change in the phase of the receiving signal, in fsk we can using only 2 frequencies Read More
What are modulation techniques in satellite communication?
What are the advantages of FSK over PSK?
We can do FSK using only two frequencies nothing else is required while in PSK we need to keep track of the change in the phase of the receiving signal. Read More
What is the difference between PSK and QPSK?
in psk,we use only single type of phase shift for a bit transition. in qpsk,we use 4 types of phase shifts for a bit transition. Read More
According to following constellation diagram if bit rate is 6400 bps what is the Baud Rate?
From the given constellation diagram determine whether its ASK, FSK, PSK or n-QAM. Then use the appropriate value of r to get Baud Rate = Bit Rate/r. Read More
What is the advantage and disadvantage of fsk fsk and psk modulation?
advantages of fsk are low noise,since amplitude is constant power requirement is constant operates in virtually any wires available high data rate used in long distance communication easy to decode good sensitivity Read More
Difference between absolute PSK and differential PSK?
In abs. PSK only instant phase for the incoming bits are considered. For DPSK, the difference between previous phase and the present phase is considered. Example: If BPSK is used, then for 0 if phase if pi and for 1 it is 0, then for abs. BPSK the phase states for the bit stream 1010 will be 0,pi,0,pi for DPSK, we assume initial phase is zero and a rule that , if incoming bit is… Read More
Why does your dsi ask you a security key is needed to connect to this access point enter the security key then tap ok and What is the security key?
The security key is the password for the wireless router. It'll show up if the wireless encryption is : WEP WPA-PSK (TKIP) WPA2-PSK(TKIP) WPA-PSK (AES) WPA2-PSK (AES). Read More
What is the advantage of qam over ask and psk?
PSK and QAM modulation have two advantages over ASK: *They are not as susceptible to noise. *Each signal change can represent more than one bit PSK Disadvantage more complex signal detection / recovery process, than in ASK and FSK QAM advantage: · data rate = 2 bits per bit-interval! · higher data rate than in PSK (2 bits per bit interval), while bandwidth occupancy remains the same • 4-PSK can easily be extended to 8-PSK… Read More
Which signaling is used in telecom?
More information needed. Telecoms use FSK, PSK, and QAM, with A/D and D/A such as PCM, APCM, Delta and Delta-Sigma. They also use X.25, Frame Relay, ATM, SONET and TCP/IP. Read More
What is wpa-psk in wifi configuration?
WPA-PSK is a type of encryption which must be used if you have choose between WEP and WPA-PSK. If you have an option to use WPA-PSK2 to use it because it's even better. PS: The problem with WEP is that it takes about 5 minutes to hack it. For WPA-PSK with password of at least 8 symbols it might take years if the password is complicated enough. Read More
What does psk stand for?
PSK stands for Portland Street Krew and its on the Eastside of Portland! Read More
The advantage of dpsk over coherent psk?
Where can you find your wpa-psk?
It should be in wireless properties of the router under 'Security'. Some older router do not support WPA-PSK, check the manual to confirm. You must be logged on as a Root or administrator. Read More
Analog and digital communication?
In Analog communication, the analog message signal modulates some high carrier frequency inside the transmitter to produce modulated signal.this modulated signal is then transmitted with the help of a transmitting antenna to travel through the transmission channel. At the receiver, this modulated signal is received and processed to recover the original message signal. Example: AM , FM radio transmission an TV transmission. In digital communication, the message signal to be transmitted is digital in nature… Read More
How can you make your psp connect with wpa2-psk?
The PSP does not support WPA2, and there's nothing you can do about it from the PSP's side. You'd have to change your router settings to WPA at least. Read More
Who is the leader of a jewish bar mitzvah?
Steve,Unfortunately attacking WPA-PSK doesn't reqriue any kind of Evil-Twin or MITM (or any kind of ARP hijinks) if you have the PSK. All you have to do is capture the 4-way handshake for a session, and with the PSK in hand, derive the same PTK to decrypt traffic.The PTK is derived from the PMK (basically a derivation of the PSK) and a pair of nonces generated by the client station and the access point. These… Read More
What are the advantages of QAM over PSK?
What type of modulation used in digital systems?
How do you unlock security code for wpa psk?
What is m-ary psk?
Who were the Bulgarian League in 1945?
PSK Levski were the Bulgarian League winners in 1945. Read More
What are the advantages of DPSK over PSK?
1.Simple circut 2.No need of demodulation Read More
Which wireless internet connection is best?
How do we design binary phase shift keying modulator with detail circuit?
Which modulation is used with digital data?
What is a recommended method of wireless encryption?
Why digital modulation is not enough for radio transmission and what are the general goals for digital modulation?
Worldwide regulation always uses FDM for separating different systems (TV, WLAN, radio, satellite …). Thus, all radio systems must modulate the digital signal onto a carrier frequency using analogue modulation. The most prominent system is the traditional radio: all music and voice use frequencies between, e.g., 10 Hz and 22 kHz. However, many different radio stations want to transmit at the same time. Therefore, all the original signals (which use the same frequency range) must… Read More
What is the airport code for New River Valley Airport?
The airport code for New River Valley Airport is PSK. Read More
Why is obama PSK referred to as the mediator of the Copenhagen Treaty of the Great Apostasy of Daniel 927?
When will the Chinese finally wake up and realize that they are being used as a Goldman Sach's PSK tool?
Why non-coherent detector is impossible for PSK?
Why not? It is possible. Try to search for 'Non-coherent sequence detection' Read More
G and b modes in wireless netgear router?
g & b allows older 802.11g and 802.11b wireless stations to access this device. You might want to select this mode if you have a wireless station that is using WEP security and does not support WPA-PSK or WPA2-PSK. Read More
What has the author Zhi Ding written?
Zhi Ding has written: 'Performance of homodyne PSK demodulation in coherent optical communications' Read More
Why Qpsk?
QPSK is used in CDMA because it helps achieve higher data rates. It is much better than simple PSK. Read More
What has the author Kemal Burkay written?
Kemal Burkay has written: 'Sorular ve cevaplarla PSK ne diyor? ne istiyor?' Read More
What is QPSK?
QPSK = Quadrature Phase Shift Keying In QPSK amplitude are not much.so the carrier is constant. transmission rate is higher when compared with PSK Read More
What does the name samita mean?
From where I came from, Samita means smile or powder. I hope this helps you know the meaning of your friends name or relative or whoever it is!!!!! PSK Read More
Is it possible to transmit a digital signal coded as square wave as used inside a computer using radio transmission without loss?
Digital signals are regularly transmitted by radio systems. The traditional way of doing it was by frequency-shift keying (FSK) where the frequency was changed slightly between two states which represented logical 0 and 1. Another method uses phase-shift keying (PSK) which uses two phase states of the carrier wave to represent 0 and 1. The main issue in transmitting data by radio is the bandwidth, and with 2-state modulation like FSK or PSK the bandwidth… Read More
Where do you find your WPA code for the xbox 360?
To find the WPA-PSK code, you need to look on the bottom of your router, the code will be found near the 'I.P.' address. Read More
What are the most predominant modulation schemes use in digital radio system?
-- PSK -- DPSK -- 16, 32, 64, 128, and 256 QAM Read More
Three main protocols for encryption for 802.11?
For WiFi there are WEP, WPA2, and WPA2-PSK types of security, with encryption for WPA2 being either AES of TKIP. Read More
A PSK signal uses phase shifts of 45 degrees and has a bit rate of 9000 bps. What is the minimum bandwidth that the signal requires?
How do you get into your wi fi if it says disabled secured with wpa wpa2 psk?
Read the owners manuals for the devices you are working with and reset the access point to its default settings. Read More
Which type of encrytion method is recommened for a wireless home network to secure the wireless communication?
It's called WPA2-PSK AES. You also can use MAC filters. Read More
What is ANIW2CS2 Service?
These 2 services are the WPA supplicant for the D-Link wireless utility. They are integrated in the D-Link utility to give you WPA/WPA-PSK support Read More
Where do you get a wpa2-psk code for your DSi?
The WPA code is the security passcode for your wireless router, just enter it in the same way that it is entered into your computer's wireless connection settings. Read More
What method used to secure wireless network?
To use protected by key wireless networks (WPA, WPA2-PSK AES), MAC filters, deny access to ports which are not used. Read More
Which is safe wired or wireless commnunication?
The safest is fiber optics. Nowadays wireless N with WPA2-PSK encryption allows you safely to operate within encrypted network. Read More
Digital-to-Analog signals is the next conversion we will discuss in this chapter. These techniques are also called as Digital Modulation techniques.
Digital Modulation provides more information capacity, high data security, quicker system availability with great quality communication. Hence, digital modulation techniques have a greater demand, for their capacity to convey larger amounts of data than analog modulation techniques.
There are many types of digital modulation techniques and also their combinations, depending upon the need. Of them all, we will discuss the prominent ones.
ASK – Amplitude Shift Keying
The amplitude of the resultant output depends upon the input data whether it should be a zero level or a variation of positive and negative, depending upon the carrier frequency.
FSK – Frequency Shift Keying
The frequency of the output signal will be either high or low, depending upon the input data applied.
PSK – Phase Shift Keying
The phase of the output signal gets shifted depending upon the input. These are mainly of two types, namely Binary Phase Shift Keying (BPSK) and Quadrature Phase Shift Keying (QPSK), according to the number of phase shifts. The other one is Differential Phase Shift Keying (DPSK) which changes the phase according to the previous value.
M-ary Encoding
M-ary Encoding techniques are the methods where more than two bits are made to transmit simultaneously on a single signal. This helps in the reduction of bandwidth.
The types of M-ary techniques are −
- M-ary ASK
- M-ary FSK
- M-ary PSK
All of these are discussed in subsequent chapters.