Skip to main content

Comparisons among ASK, PSK, and FSK (with MATLAB + Simulator)


Comparisons among ASK, PSK, and FSK

Comparison among ASK, FSK, and PSK
Parameters ASK FSK PSK
Variable Characteristics Amplitude Frequency Phase
Bandwidth The minimum theoretical bandwidth for BASK is equal to the bit rate, Nb. The bandwidth requirement is approximately (fc2 - fc1) + Nb. The bandwidth is always greater than ASK. The minimum theoretical bandwidth for BPSK is equal to the bit rate, Nb. It is more bandwidth-efficient than FSK.
Noise Immunity Poor. Amplitude is highly susceptible to noise interference. Good. Less affected by noise than ASK as information is in frequency, not amplitude. Excellent. Offers the best noise immunity of the three for the same signal power.
Complexity Simple to implement. More complex than ASK. Most complex, as it requires a phase-synchronous (coherent) detector.

Comparison of Performance

Feature ASK (OOK) BFSK BPSK
Power Efficiency Low Medium High
Bandwidth Efficiency High Low High
Noise Immunity Poor (Sensitive to Amp) Good Excellent
Best Used In Fiber Optics, RFID Caller ID, Paging Deep Space, Satellite

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 are same for binary ASK, FSK, and PSK.

Comparison among ASK, FSK, and PSK

Performance Comparison:

1. Noise Sensitivity:

- ASK is the most sensitive to noise due to its reliance on amplitude variations.
- PSK is less sensitive to noise compared to ASK.
- FSK is relatively more robust against noise, making it suitable for noisy environments.

2. Bandwidth Efficiency:

- PSK is the most bandwidth-efficient, requiring less bandwidth than FSK for the same data rate.
- FSK requires wider bandwidth compared to PSK.
- ASK's bandwidth efficiency lies between FSK and PSK.

3. Complexity:

- ASK and FSK are relatively simpler to implement and demodulate.
- Coherent PSK demodulation can be more complex due to carrier synchronization requirements.

4. Fading and Multipath Resilience:

- FSK performs well in fading and multipath scenarios due to its frequency diversity properties.
- PSK can be affected by fading, especially in frequency-selective fading conditions.
- ASK may experience significant performance degradation in fading and multipath channels.

5. Applications:

- ASK is commonly used in simple applications such as remote controls, RFID, and binary communication.
- FSK is suitable for applications where noise immunity is important, such as wireless communication and telemetry systems.
- PSK is widely used in digital communication systems, including modems, Wi-Fi, and digital broadcasting.

The choice of modulation technique depends on the specific requirements of the communication system, including the channel characteristics, noise levels, data rate, and complexity constraints. Each modulation technique has its strengths and weaknesses, and the best choice will depend on balancing these factors for the given scenario.

ASK vs. FSK vs. BPSK: Key Differences

Feature ASK FSK BPSK
Parameter Changed Amplitude Frequency Phase
Noise Immunity Low (Very Sensitive) High Very High
Bandwidth Efficiency High Low High
Complexity Simple Moderate Complex

ASK Applications

  • • Optical Fiber Communications
  • • Infrared Remote Controls
  • • Early Wireless Telegraphy

FSK Applications

  • • Caller ID Systems
  • • Garage Door Openers
  • • Low-speed Radio Modems

BPSK Applications

  • • Deep Space Telemetry
  • • Satellite Communications
  • • GPS Navigation Signals

Graphical or plot representation of ASK, FSK, and PSK

Message Signal

Carrier Signal

ASK Signal

FSK Signal

PSK Signal

The above figures show that the carrier frequency for ASK is 10 Hz. For PSK, that is 5 Hz. But for FSK, carrier frequencies are 10 Hz and 2 Hz

Summary

  • ASK is simple to generate, and it has a less complex circuitry in comparison to FSK and PSK
  • As noise is very sensitive to amplitude so it has poor noise immunity.
  • FSK is less susceptible to errors than ASK
  • FSK is suitable for high-frequency communication as modulation deals with two different high carrier frequencies here.
  • FSK circuitry is moderately complex
  • The bit rate in FSK is higher than in ASK
  • In FSK, noise immunity is high
  • PSK circuitry is very complex
  • PSK has a higher bit rate as compared to FSK
  • PSK has better noise immunity than FSK

Why are ASK, FSK, and PSK used?

Electronic devices are sensitive to amplitude, frequency, and phase, so these three digital modulation techniques are used during wireless data transfer.

Comparison of BER vs SNR among ASK, FSK, and PSK in MATLAB



(Get MATLAB Code)

Fig 2: Comparison of BER vs SNR among ASK, FSK, and PSK

% BER vs SNR Comparison Code Placeholder
% Visit the link above for the full script.
SNR = 0:1:10;
BER_ASK = 0.5*erfc(sqrt(10.^(SNR/10)/4));
semilogy(SNR, BER_ASK);
grid on;
      

Some Questions and Answers (Q&As)

  1. In a coherent Frequency Shift Keying (FSK) system, what is the primary challenge in achieving coherent detection?
    Answer: Maintaining phase synchronization between transmitter and receiver.
    Explanation: Coherent detection requires maintaining phase synchronization to correctly demodulate the signal.
  2. Which of the following is a major disadvantage of Amplitude Shift Keying (ASK)?
    Answer: Susceptibility to noise and interference.
    Explanation: ASK is highly susceptible to noise because it relies on amplitude changes.
  3. Which modulation scheme is typically more bandwidth-efficient?
    Answer: Phase Shift Keying (PSK).
    Explanation: PSK is more bandwidth-efficient because it encodes information in phase shifts.
  4. In Phase Shift Keying (PSK), what is the impact of increasing the number of phase states?
    Answer: Higher data rates.
    Explanation: More phase states allow higher data rates as more bits can be encoded per symbol.
  5. Which of the following is a key advantage of using Non-Coherent FSK over Coherent FSK?
    Answer: Simpler receiver design.
    Explanation: Non-Coherent FSK has a simpler receiver design because it does not require phase synchronization.
  6. Why is Phase Shift Keying (PSK) considered more power efficient than Frequency Shift Keying (FSK)?
    Answer: PSK can maintain performance at lower signal-to-noise ratios.
    Explanation: PSK is more power efficient because it can achieve good performance at lower signal-to-noise ratios.
  7. Which characteristic of FSK modulation makes it advantageous for certain applications?
    Answer: Its robustness in high-noise environments.
    Explanation: FSK is robust in noisy environments because the frequency changes are distinct.
  8. What is the primary disadvantage of using higher-order PSK modulation schemes?
    Answer: Increased sensitivity to noise.
    Explanation: Increased sensitivity to noise due to smaller phase differences between symbols.
  9. Which modulation scheme is typically used in radio broadcasting?
    Answer: Frequency Modulation (FM).
    Explanation: FM is commonly used in radio broadcasting due to its robustness to noise.
  10. In a PSK system, what can be used to improve error performance?
    Answer: Using error correction coding.
    Explanation: Error correction coding helps to detect and correct errors, improving performance.
Wireless Communication Main Page > BER vs SNR Main Page > Online Signal Processing Simulations Main Page > Wireless Communication in MATLAB Main Page >


Contact Us

Name

Email *

Message *

Popular Posts

LDPC Encoding and Decoding Techniques

Low Density Parity Check (LDPC) Guide Comprehensive analysis of linear error-correcting block codes, Tanner graphs, and 5G-NR implementations. ๐Ÿ“˜ Overview ๐Ÿงฎ Encoding ๐Ÿงฉ Decoding ๐Ÿ“š Resources Theory Encoding Tech Tanner Graph 5G Encoding Decoding 'LDPC' is the abbreviation for 'low density parity check'. LDPC code H matrix contains very few amount of 1's and mostly zeroes. LDPC codes are error correcting code. Using LDPC codes, channel capacities that are close to the theoretical Shannon limit can be achieved. Low density parity check (LDPC) codes are linear error-correcting block code suitable for error correction in a large block sizes transmi...

Flat vs Frequency Selective Online Simulator

Flat vs Frequency Selective Online Simulator Channel Type Without Fading Flat Fading Multipaths Nakagami m SNR(dB) Run Simulation Input Signal Signal After Fading Constellation Diagram BER vs SNR Explore Advanced Flat vs Frequency-Selective Fading Simulator Want to see these equations in action? Visualize it. Launch Simulator Tool Interactive Rayleigh Fading Simulator Want to see Rayleigh fading in action? Visualize it. Launch Simulator Tool Return to DSP Simulations Main Page →

Q-function in BER vs SNR Calculation (with Simulation)

Q-function in BER vs. SNR Calculation In digital communications and signal processing, the Q-function plays a significant role in predicting system reliability. It allows engineers to quantify the probability that Gaussian noise will exceed a specific threshold, causing a bit error. What is the Q-function? The Q-function is a mathematical function representing the tail probability of the standard normal (Gaussian) distribution. It is the complementary cumulative distribution function (CCDF) of a standard Gaussian distribution. Q(x) = (1 / √(2ฯ€)) ∫โ‚“∞ e^(-t² / 2) dt The Role of the Q-function in BER vs. SNR The Q-function is the standard tool for calculating BER in systems like BPSK or QPSK over AWGN (Additive White Gaussian Noise) channels. For BPSK: In BPSK, we transmit +√E b (bit 1) and -√E b (bit 0). The decision boundary is set at 0 . If -√E b was sent, an error occurs if noise r > √...

Design of CMOS Flip-Flops (SR, D, JK)

Design of CMOS Flip-Flops (SR, D, JK) A flip-flop or latch is a circuit with two stable states, used to store state information. It is the basic storage element in sequential logic and a fundamental building block in digital electronics systems, including computers and communication devices. Flip-flops and latches act as data storage elements for states, pulse counting, and synchronization of variably-timed input signals to a reference clock. Flip-flops can be transparent/opaque (latches) or clocked (synchronous, edge-triggered). Latches are level-sensitive, while flip-flops are edge-sensitive. In sequential logic, the output depends on current inputs and previous states. Fig.1 shows a sequential circuit combining a combinational block and a memory element. ...

Online Simulator for ASK, FSK, and PSK Signal Generation

Interactive Digital Signal Processing (DSP) Tutorial and Simulator for ASK, FSK, and BPSK modulation techniques. Try our new Digital Signal Processing Simulator!   •   Interactive ASK, FSK, and BPSK tools updated for 2025. Start Now Digital Modulation Visualizer: ASK, FSK, & BPSK Simulator Learn and visualize binary modulation techniques (ASK, FSK, BPSK) in real-time with adjustable carrier and sampling parameters. Perfect for DSP students and engineers. ๐Ÿ“ก ASK Simulator ๐Ÿ“ถ FSK Simulator ๐ŸŽš️ BPSK Simulator ๐Ÿ“š More Topics ASK Modulator FSK Modulator BPSK Modulator Demodulation More Topics 1. ASK (Ampli...

Gaussian minimum shift keying (GMSK)

๐Ÿ“˜ Overview & Theory ๐Ÿงฎ Simulator for GMSK ๐Ÿงฎ MSK and GMSK: Understanding the Relationship ๐Ÿงฎ MATLAB Code for GMSK ๐Ÿ“š Simulation Results for GMSK ๐Ÿ“š Q & A and Summary ๐Ÿ“š Further Reading Dive into the fascinating world of GMSK modulation, where continuous phase modulation and spectral efficiency come together for robust communication systems! Core Process of GMSK Modulation Phase Accumulation (Integration of Filtered Signal) After applying Gaussian filtering to the Non-Return-to-Zero (NRZ) signal, we integrate the smoothed signal to produce a continuous phase signal. For GMSK, the modulation index is $h=0.5$, meaning a bit '1' results in a phase shift of $\pi/2$: ฮธ(t) = 2ฯ€h ∫ 0 t m filtered (ฯ„) dฯ„ This integration is crucial for avoiding abrupt phase transitions, ensuring smooth and continuous phase changes. Phase Mo...

Online Simulator for Frequency Modulatiuon and Demodulation

FM Modulation Simulator Frequency Modulation (FM) In Frequency Modulation, the frequency of the carrier signal varies in accordance with the message signal's amplitude. s FM (t) = A c cos(ฯ‰ c t + k f ∫m(t)dt) where ฯ‰ = 2ฯ€f & k f = Frequency Sensitivity Modulation index, ฮฒ = (k f * A m ) / f m Change the parameter values to see the effect. Message Freq (Hz) 1 Carrier Freq (Hz) Message Amplitude (Am) Kf (sensitivity): 50 Perform FM Demodulation ๐Ÿงช Experiment for Students: ...