Skip to main content

ASK, FSK, and PSK


 

ASK or OFF ON Keying

Ask is a simple (less complex) Digital Modulation Scheme where we vary the modulation signal's amplitude or voltage by the message signal's amplitude or voltage. We select two levels (two different voltage levels) for transmitting modulated message signals for the exam. And for example, we mapped the signal as two-level "+5 Volt" (which is the upper level) and another level, "0 Volt," which is considered as the lower level. Whenever we need to transmit binary bit "1," then the transmitter transmits a signal of "+5 Volts," and when we need to send bit "0," then it transmits no power. But the receiver is intelligent enough to deflect whether you've sent binary bit "1" or "0" by deflecting with quipped filters that can distinguish strings of bits. It is possible by the switching capability of the filter with the particular period to determine each bit from a string of bits.  

 
 

Fig 1: Output of ASK, FSK, and PSK modulation using MATLAB for a data stream "1   1    0   0   1    0   1   0"

FSK

Like other modulation techniques, the message signal is modulated with the high-frequency carrier wave,e, and then two binary values are represented by two different frequencies. The two frequencies are near the carrier frequency. For example, 

We choose two carrier frequencies, f1 and f2, and f1 > f2. Then we modulate binary bit "1" with f1 and binary "0" with f2 frequency, which is a lower frequency than f1. Now, the modulated signal will look like that,

S1(t) = A cos 2ฯ€fc1t      for  binary 1   

And S2(t) = A cos 2ฯ€fc2t      for  binary 0

Here, fc1 is different from f1. As you know, when the signal goes thru the modulation process, the frequency of the modulated signal is different from the carrier signal by the message signal's frequency.


PSK

In PSK, here,e the carrier signal phase is with a modulated signal with the phase related to the last bit for binary "1," and binary "0" is sent with a signal with the same phase as the preceding one. For example, whenever we need to transmit binary "1", we change the signal's phase by 180 degree, but the phase remains the same when we transmit binary "0". PSK carrier is used as follows

s(t) = A cos (2ฯ€fct + ฯ€)    for binary 1

s(t) = A cos (2ฯ€fct)           for binary 0 


Which of the modulation techniques—ASK, FSK, or PSK—can achieve higher bit rates?

Among ASK, FSK, and PSK, PSK (Phase Shift Keying) can generally achieve higher bit rates.

Here's why:

PSK (Phase Shift Keying):

Phase Shift Keying, or PSK, uses various phase shifts to encode extra bits per symbol. For instance, QPSK (Quadrature Phase Shift Keying) doubles the data rate over binary PSK by representing two bits each signal.

The bit rate can be further increased by using higher-order PSK methods, such as 8-PSK and 16-PSK, which can encode even more bits per symbol.


FSK (Frequency Shift Keying):

Because FSK often requires a higher frequency separation to discriminate between different symbols, fewer bits can be broadcast in a given bandwidth, resulting in a lower bit rate than PSK.

Although there are higher-order FSK systems, PSK is more bandwidth-efficient than them.


ASK (Amplitude Shift Keying):

ASK's ability to successfully raise bit rates is limited by its lower bit rate efficiency and increased susceptibility to noise and interference.

Bit rates can be increased via higher-order ASK (such as QAM, which combines ASK and PSK), but pure ASK is typically less effective than PSK.

In conclusion, among these three modulation strategies, PSK has the potential to produce the highest bit rates, particularly when utilising higher-order modulation techniques.


Simulator for binary ASK, FSK, and PSK Modulation

Further Reading

  1. Amplitude, Frequency, and Phase Modulation
  2. Online Simulator for Amplitude Modulation (AM)
  3. Digital Communication System Simulator
  4. Comparisons among ASK, PSK, and FSK
  5. Simulation of ASK, FSK, and PSK using MATLAB Simulink
  6. MATLAB Code for ASK, FSK, and PSK
  7. Constellation Diagrams of ASK, PSK, and FSK
  8. Theoretical and simulated BER vs. SNR for ASK, FSK, and PSK
  9. MATLAB Code for Constellation Diagrams of ASK, FSK, and PSK

People are good at skipping over material they already know!

View Related Topics to







Admin & Author: Salim

s

  Website: www.salimwireless.com
  Interests: Signal Processing, Telecommunication, 5G Technology, Present & Future Wireless Technologies, Digital Signal Processing, Computer Networks, Millimeter Wave Band Channel, Web Development
  Seeking an opportunity in the Teaching or Electronics & Telecommunication domains.
  Possess M.Tech in Electronic Communication Systems.


Contact Us

Name

Email *

Message *

Popular Posts

BER vs SNR for M-ary QAM, M-ary PSK, QPSK, BPSK, ...

๐Ÿ“˜ Overview of BER and SNR ๐Ÿงฎ Online Simulator for BER calculation of m-ary QAM and m-ary PSK ๐Ÿงฎ MATLAB Code for BER calculation of M-ary QAM, M-ary PSK, QPSK, BPSK, ... ๐Ÿ“š Further Reading ๐Ÿ“‚ View Other Topics on M-ary QAM, M-ary PSK, QPSK ... ๐Ÿงฎ Online Simulator for Constellation Diagram of m-ary QAM ๐Ÿงฎ Online Simulator for Constellation Diagram of m-ary PSK ๐Ÿงฎ MATLAB Code for BER calculation of ASK, FSK, and PSK ๐Ÿงฎ MATLAB Code for BER calculation of Alamouti Scheme ๐Ÿงฎ Different approaches to calculate BER vs SNR What is Bit Error Rate (BER)? The abbreviation BER stands for bit error rate, which indicates how many corrupted bits are received (after the demodulation process) compared to the total number of bits sent in a communication process. It is defined as,  In mathematics, BER = (number of bits received in error / total number of transmitted bits)  On the other hand, SNR ...

Comparisons among ASK, PSK, and FSK | And the definitions of each

๐Ÿ“˜ Comparisons among ASK, FSK, and PSK ๐Ÿงฎ Online Simulator for calculating Bandwidth of ASK, FSK, and PSK ๐Ÿงฎ MATLAB Code for BER vs. SNR Analysis of ASK, FSK, and PSK ๐Ÿ“š Further Reading ๐Ÿ“‚ View Other Topics on Comparisons among ASK, PSK, and FSK ... ๐Ÿงฎ Comparisons of Noise Sensitivity, Bandwidth, Complexity, etc. ๐Ÿงฎ MATLAB Code for Constellation Diagrams of ASK, FSK, and PSK ๐Ÿงฎ Online Simulator for ASK, FSK, and PSK Generation ๐Ÿงฎ Online Simulator for ASK, FSK, and PSK Constellation ๐Ÿงฎ Some Questions and Answers Modulation ASK, FSK & PSK Constellation MATLAB Simulink MATLAB Code Comparisons among ASK, PSK, and FSK    Comparisons among ASK, PSK, and FSK   Simulator for Calculating Bandwidth of ASK, FSK, and PSK The baud rate represents the number of symbols transmitted per second. Both baud rate and bit rate a...

Constellation Diagrams of ASK, PSK, and FSK

๐Ÿ“˜ Overview ๐Ÿงฎ Online Simulator for constellation diagrams of ASK, FSK, and PSK ๐Ÿงฎ Theory ๐Ÿงฎ MATLAB Codes ๐Ÿงฎ Simulator for constellation diagrams of m-ary PSK ๐Ÿงฎ Simulator for constellation diagrams of m-ary QAM ๐Ÿ“š Further Reading BASK (Binary ASK) Modulation: Transmits one of two signals: 0 or -√Eb, where Eb​ is the energy per bit. These signals represent binary 0 and 1.    BFSK (Binary FSK) Modulation: Transmits one of two signals: +√Eb​ ( On the y-axis, the phase shift of 90 degrees with respect to the x-axis, which is also termed phase offset ) or √Eb (on x-axis), where Eb​ is the energy per bit. These signals represent binary 0 and 1.  BPSK (Binary PSK) Modulation: Transmits one of two signals: +√Eb​ or -√Eb (they differ by 180 degree phase shift), where Eb​ is the energy per bit. These signals represent binary 0 and 1.    Simulator for BASK, BPSK, and BFSK Constellation Diagrams ...

RMS Delay Spread, Excess Delay Spread and Multi-path ...

๐Ÿ“˜ Overview ๐Ÿงฎ Multipath Components or MPCs ๐Ÿงฎ Excess Delay spread ๐Ÿงฎ Power delay Profile ๐Ÿงฎ RMS Delay Spread ๐Ÿงฎ Simulator for Calculating RMS Delay Spread ๐Ÿงฎ Why is there significant multipath in the case of very high frequencies? ๐Ÿงฎ Why RMS Delay Spread is essential for wireless communication? ๐Ÿงฎ Why the Power Delay Profile is essential? ๐Ÿงฎ MATLAB Codes ๐Ÿ“š Further Reading Signal Processing RMS Delay Spread, Excess Delay Spread, and Multipath... RMS Delay Spread, Excess Delay Spread, and Multipath (MPCs) The fundamental distinction between wireless and wired connections is that in wireless connections signal reaches at receiver thru multipath signal propagation rather than directed transmission like co-axial cable. Wireless Communication has no set communication path between the transmitter and the receiver. The line of sight path, also known as the LOS path, is the shortest and most direc...

MATLAB Code for Pulse Amplitude Modulation (PAM) and Demodulation

๐Ÿ“˜ Overview & Theory ๐Ÿงฎ MATLAB Code for Pulse Amplitude Modulation and Demodulation of an Analog Signal ๐Ÿงฎ MATLAB Code for Pulse Amplitude Modulation and Demodulation of an Analog Signal (2) ๐Ÿงฎ MATLAB Code for Pulse Amplitude Modulation and Demodulation of Digital data ๐Ÿงฎ Simulation results for comparison of PAM, PWM, PPM, DM, and PCM ๐Ÿงฎ Other Pulse Modulation Techniques (e.g., PWM, PPM, DM, and PCM) ๐Ÿ“š Further Reading   Pulse Amplitude Modulation (PAM) & Demodulation of an Analog Message Signal MATLAB Script clc; clear all; close all; fm= 10; % frequency of the message signal fc= 100; % frequency of the carrier signal fs=1000*fm; % (=100KHz) sampling frequency (where 1000 is the upsampling factor) t=0:1/fs:1; % sampling rate of (1/fs = 100 kHz) m=1*cos(2*pi*fm*t); % Message signal with period 2*pi*fm (sinusoidal wave signal) c=0.5*square(2*pi*fc*t)+0.5; % square wave with period 2*pi*fc s=m.*c; % modulated signal (multiplication ...

Relationship between Gaussian and Rayleigh distributions

๐Ÿ“˜ Introduction, Gaussian Distribution, Relationship Between Gaussian and Rayleigh Distribution ๐Ÿงฎ How to mitigate Rayleigh fading? ๐Ÿงฎ Equalizer to reduce Rayleigh Fading (or Multi-path Effects) in MATLAB ๐Ÿงฎ MATLAB Code for Effects of AWGN and Rayleigh Fading in Wireless Communication ๐Ÿงฎ Simulator for the effect of AWGN and Rayleigh Fading on a BPSK Signal ๐Ÿ“š Further Reading Wireless Signal Processing Gaussian and Rayleigh distributions ...   The Rayleigh distribution in classical fading models (like wireless communication) arises from modeling the real and imaginary parts of a complex baseband signal as independent, zero-mean Gaussian random variables — under specific assumptions . 1. Gaussian Distribution  The Gaussian distribution has a lot of applications in wireless communication. Since noise in wireless communication systems is unpredictable, we frequently assume that it has a Gaussian distribution...

Difference between AWGN and Rayleigh Fading

๐Ÿ“˜ Introduction, AWGN, and Rayleigh Fading ๐Ÿงฎ Simulator for the effect of AWGN and Rayleigh Fading on a BPSK Signal ๐Ÿงฎ MATLAB Codes ๐Ÿ“š Further Reading Wireless Signal Processing Gaussian and Rayleigh Distribution Difference between AWGN and Rayleigh Fading 1. Introduction Rayleigh fading coefficients and AWGN, or additive white gaussian noise [↗] , are two distinct factors that affect a wireless communication channel. In mathematics, we can express it in that way.  Fig: Rayleigh Fading due to multi-paths Let's explore wireless communication under two common noise scenarios: AWGN (Additive White Gaussian Noise) and Rayleigh fading. y = h*x + n ... (i) Symbol '*' represents convolution. The transmitted signal  x  is multiplied by the channel coefficient or channel impulse response (h)  in the equation above, and the symbol  "n"  stands for the white Gaussian noise that is added to the si...

MATLAB Codes for Various types of beamforming | Beam Steering, Digital...

Beamforming Techniques MATLAB Codes for Beamforming... The mathematical [↗] and theoretical aspects of beamforming [↗] have already been covered. We'll talk about coding in MATLAB in this tutorial so that you may generate results for different beamforming approaches. Let's go right to the content of the article. In analog beamforming, certain codebooks are employed on the TX and RX sides to select the best beam pairs. Because of their beamforming gains, communication created through the strongest beams from both the TX and RX side enhances spectrum efficiency. Additionally, beamforming gain directly impacts SNR improvement. Wireless communication system capacity = bandwidth*log2(1+SNR) bits/s. Thus, the capacity or overall throughput of the system increases. MATLAB Script %Written by Salim Wireless %Visit www.salimwireless.com for study materials on wireless communication %or, if you want to learn how to code in MATLAB clear all;...