[Paper Review] Implementation of ASK, FSK and PSK with BER vs. SNR comparison over AWGN channel

Subrato Bharati, Mohammad Atikur Rahman+1 more|arXiv (Cornell University)|Feb 10, 2020

Advanced Wireless Communication Techniques8 references4 citations

TL;DR

This paper implements and compares the bit error rate (BER) performance of ASK, FSK, and PSK modulation schemes over an additive white Gaussian noise (AWGN) channel using MATLAB. It demonstrates that PSK exhibits the best BER performance across all SNR levels, followed by FSK and then ASK, with BER curves showing clear SNR-dependent error degradation for each scheme.

ABSTRACT

This paper mainly discusses about three basic digital modulation process ASK, FSK, PSK. These modulation schemes can be characterized by their transmitted symbols which consist of a discrete set of values occurring at gradually spaced intervals. The selection of a digital modulation technique for a specific application depend not only the bandwidth efficiency and implementation complexity but also error rate occurred in a bit (BER) and signal to noise ratio. Binary modulation methods use two level symbols and are facile to implement, provide good error substantiation. BER is a key parameter that used for assessing systems that transmit signal data from one location to another. SNR is well known measure of how the signal and noise power compare against each other. It directly affects the probability of error performance of a system. In this paper, we have implemented ASK, FSK and PSK using MATLAB. Cosine signal has been used as a carrier wave. In this paper, a comparative exploration of BER performance of ASK, FSK and PSK for channel utilization is proposed and the investigation are carried out with SNR over AWGN channel as the reference factor.

Motivation & Objective

• To evaluate and compare the bit error rate (BER) performance of three common digital modulation schemes: Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK), and Phase Shift Keying (PSK).
• To analyze how BER varies with signal-to-noise ratio (SNR) in an additive white Gaussian noise (AWGN) channel environment.
• To provide a practical implementation of ASK, FSK, and PSK using MATLAB for educational and analytical purposes.
• To determine the relative error resilience of each modulation technique under identical channel conditions.
• To support system design decisions by quantifying the trade-offs between implementation complexity, bandwidth efficiency, and error performance.

Proposed method

• The study uses MATLAB to simulate the baseband transmission of binary data using ASK, FSK, and PSK modulation techniques.
• A cosine carrier wave is employed in the modulation process to generate the respective modulated signals.
• The simulated signals are transmitted over an AWGN channel, where noise is added based on specified SNR levels.
• The receiver performs coherent detection: matched filtering or correlation-based demodulation is applied to recover the transmitted bits.
• BER is computed by comparing the transmitted and detected bit sequences across multiple SNR values.
• The BER performance curves are plotted against SNR to enable visual and quantitative comparison of the three modulation schemes.

Experimental results

Research questions

• RQ1 How does the bit error rate (BER) of ASK, FSK, and PSK vary with increasing signal-to-noise ratio (SNR) in an AWGN channel?
• RQ2 Which of the three modulation schemes—ASK, FSK, or PSK—exhibits the lowest BER across the tested SNR range?
• RQ3 What is the relative error performance ranking of ASK, FSK, and PSK under identical channel and system conditions?
• RQ4 How does the implementation complexity and error resilience of each modulation scheme compare in an AWGN environment?
• RQ5 To what extent does the choice of modulation format impact the reliability of digital communication systems in noisy environments?

Key findings

• PSK demonstrates the lowest bit error rate (BER) across all SNR levels, indicating superior error resilience compared to ASK and FSK.
• FSK exhibits better BER performance than ASK, particularly at low to moderate SNR values, due to its frequency diversity advantage.
• ASK shows the highest BER among the three schemes, especially at low SNR, due to amplitude sensitivity to noise.
• The BER curves for all three schemes show a monotonic decrease with increasing SNR, confirming the expected inverse relationship between SNR and error probability.
• The simulation results confirm theoretical expectations: PSK is the most robust modulation for AWGN channels, followed by FSK and then ASK.
• The MATLAB-based implementation successfully reproduces the expected BER vs. SNR trends, validating the accuracy of the simulation model.