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

Electromyography (EMG) Explained

  Electromyography (EMG) EMG stands for Electromyography . It is a medical test used to check how well your muscles and the nerves that control them are working. What it does EMG measures the electrical activity in your muscles. When nerves send signals to muscles, they create tiny electrical impulses—EMG records these. Why doctors use it Doctors may recommend EMG if you have symptoms like: Muscle weakness Numbness or tingling Muscle pain or cramping Suspected nerve disorders It helps diagnose conditions such as: Carpal Tunnel Syndrome Amyotrophic Lateral Sclerosis (ALS) Peripheral Neuropathy How it’s done Nerve conduction study (NCS) – small electrical pulses are applied to test nerve signals Needle EMG – a thin needle electrode is inserted into muscles to record activity Does it hurt? You might feel mild discomfort (like a quick pinch or muscle soreness) ...

MATLAB Code for MUSIC

  MATLAB Code clc; clear; close all ; %% Step 1: Define Parameters M = 8; % Number of array sensors d = 0.5; % Sensor spacing (lambda/2) K = 2; % Number of signals N = 200; % Number of snapshots theta = [-20 30]; % True signal angles (degrees) SNR = 10; % Signal-to-noise ratio (dB) fprintf( 'Step 1: Parameters Initialized\n' ); %% Step 2: Generate Signal Sources t = 1:N; s1 = exp(1j*2*pi*0.05*t); s2 = exp(1j*2*pi*0.1*t); S = [s1; s2]; figure; plot(real(S(1,:))) title( 'Signal 1 (Real Part)' ) xlabel( 'Samples' ) ylabel( 'Amplitude' ) figure; plot(real(S(2,:))) title( 'Signal 2 (Real Part)' ) xlabel( 'Samples' ) ylabel( 'Amplitude' ) fprintf( 'Step 2: Source Signals Generated\n' ); %% Step 3: Construct Steering Matrix A = zeros(M,K); for k = 1:K A(:,k) = exp(-1j*2*pi*d*(0:M-1)'*sin(theta(k)*pi/180)); end fprintf( 'Step 3: Steering Matr...

Direction of Arrival (DoA) Online Simulator (using MUSIC)

Interactive DOA Simulator X-axis XY angle (deg): 45 XZ angle (deg): 30 Noise: 0.05 Y-axis XY angle (deg): 60 YZ angle (deg): 45 Noise: 0.05 Z-axis XZ angle (deg): 60 YZ angle (deg): 30 Noise: 0.05 Estimated DOA (deg): 0 Simulation Workflow and Mathematical Background This simulator demonstrates Direction of Arrival (DOA) estimation using three-axis sensor signals (X, Y, Z), Maximal Ratio Combining (MRC) , and the MUSIC algorithm . It allows interactive control of signal angles and noise for teaching purposes. 1. Signal Generation A pure sinewave signal of frequency f is projected onto three axes using user-defined angles in different planes: X-axis: θ XY , θ XZ Y-axis: θ XY , θ YZ Z-axis: θ XZ , θ YZ Mathematically, for each time sample t : x(t) = s(t) * cos(θ_xy_x) * cos(θ_xz_x) + n_x(t) y(t) = s(t) * sin(θ_xy_y) * cos(θ_yz_y) + n_y(t) z(t) = s(t) * sin(θ_xz_z) * sin(θ_yz_z) + n_z(t) wh...

Amplitude Demodulation Simulation

Instructions for Amplitude Modulation (AM) Step 1: Click on 'Generate Message' button to generate input message signal Step 2: Then click on 'Generate Carrier' button to generate carrier signal. The carrier frequency has to be more than the message frequency and You can change frequencies using sliders Step 3: Click on 'Generate Amplitude Modulated Signal' button to generate Amplitude Modulated Signal Step 4: Click the 'Show Frequency Spectrums' button to view the AM spectra. Here, the modulation index is defined as the ratio of the message signal amplitude to the carrier signal amplitude. You can adjust both values. 50 Hz Step 1: Generate Message 500 Hz Step 2: ...

MIMO Channel Matrix | Rank and Condition Number

MIMO / Massive MIMO MIMO Channel Matrix | Rank and Condition...   The channel matrix in wireless communication is a matrix that describes the impact of the channel on the transmitted signal. The channel matrix can be used to model the effects of the atmospheric or underwater environment on the signal, such as the absorption, reflection or scattering of the signal by surrounding objects. When addressing multi-antenna communication, the term "channel matrix" is used. Let's assume that only one TX and one RX are in communication and there's no surrounding object. Here, in our case, we can apply the proper threshold condition to a received signal and get the original transmitted signal at the RX side. However, in real-world situations, we see signal path blockage, reflections, etc.,  (NLOS paths [↗]) more frequently. The obstruction is typically caused by building walls, etc. Multi-antenna communication was introduced to address this issue. It makes diversity app...

UGC NET Electronic Science Previous Year Question Papers with Solutions

Home / Engineering & Other Exams / UGC NET 2026 PYQ ⬇️ Download Papers and Solutions 📋 Exam Pattern 💡 Preparation Tips ❓ FAQs 📊 Exam Highlights: Electronic Science (88) Feature Details Junior Research Fellowship (JRF) ₹37,000 + HRA per month Eligibility M.Sc/M.Tech in Electronics (55%) Validity of Certificate JRF (3 Years) | Lectureship (Lifetime) 📥 Download UGC NET Electronics PDFs Complete collection of previous year question papers, answer keys and explanations for Subject Code 88. Start Downloading 📂 View All Question Papers June 2025 - Question Paper Download PDF June 2025 - Solved Paper + Explanation ...

OFDM Symbols and Subcarriers Explained

This article explains how OFDM (Orthogonal Frequency Division Multiplexing) symbols and subcarriers work. It covers modulation, mapping symbols to subcarriers, subcarrier frequency spacing, IFFT synthesis, cyclic prefix, and transmission. Step 1: Modulation First, modulate the input bitstream. For example, with 16-QAM , each group of 4 bits maps to one QAM symbol. Suppose we generate a sequence of QAM symbols: s0, s1, s2, s3, s4, s5, …, s63 Step 2: Mapping Symbols to Subcarriers Assume N sub = 8 subcarriers. Each OFDM symbol in the frequency domain contains 8 QAM symbols (one per subcarrier): Mapping (example) OFDM symbol 1 → s0, s1, s2, s3, s4, s5, s6, s7 OFDM symbol 2 → s8, s9, s10, s11, s12, s13, s14, s15 … OFDM sym...