Skip to main content

BER performance of QPSK with BPSK, 4-QAM, 16-QAM, 64-QAM, 256-QAM, etc

 

 Compare the BER performance of QPSK with other modulation schemes (e.g., 
BPSK, 4-QAM, 16-QAM, 64-QAM, 256-QAM, etc) under similar conditions.


MATLAB Code

clear all;
close all;

% Set parameters for QAM
snr_dB = -20:2:20; % SNR values in dB
qam_orders = [4, 16, 64, 256]; % QAM modulation orders

% Loop through each QAM order and calculate theoretical BER
figure;
for qam_order = qam_orders
    % Calculate theoretical BER using berawgn for QAM
    ber_qam = berawgn(snr_dB, 'qam', qam_order);

    % Plot the results for QAM
    semilogy(snr_dB, ber_qam, 'o-', 'DisplayName', sprintf('%d-QAM', qam_order));
    hold on;
end

% Set parameters for QPSK
EbNoVec_qpsk = (-20:20)'; % Eb/No range for QPSK
SNRlin_qpsk = 10.^(EbNoVec_qpsk/10); % SNR linear values for QPSK

% Calculate the theoretical BER for QPSK using the provided formula
ber_qpsk_theo = 2*qfunc(sqrt(2*SNRlin_qpsk));

% Plot the results for QPSK
semilogy(EbNoVec_qpsk, ber_qpsk_theo, 's-', 'DisplayName', 'QPSK (Theoretical)');
hold on;

% Set parameters for BPSK
EbNoVec_bpsk = (-20:20)'; % Eb/No range for BPSK

% Calculate the theoretical BER for BPSK using the provided formula
ber_bpsk_theo = (1/2) * erfc(sqrt(10.^(EbNoVec_bpsk/10)));

% Plot the results for BPSK
semilogy(EbNoVec_bpsk, ber_bpsk_theo, 'x-', 'DisplayName', 'BPSK (Theoretical)');
hold on;

% Add labels, legend, and grid
title('BER vs SNR for Various Modulation Schemes');
xlabel('SNR (dB)');
ylabel('Bit Error Rate (BER)');
grid on;
legend('Location', 'best');

% Set y-axis limits
ylim([1e-6, 1e0]);

Copy the MATLAB Code from here

 Output


 

Are QPSK and 4-PSK same?

QPSK (Quadrature Phase Shift Keying) and 4-PSK (4-Phase Shift Keying) are related but not exactly the same.

    QPSK (Quadrature Phase Shift Keying): In QPSK, each symbol represents 2 bits of data. It modulates the carrier signal by changing its phase with four possible values (0°, 90°, 180°, 270°) corresponding to four different states. These four states can be represented in a constellation diagram with points at (1,1), (-1,1), (-1,-1), and (1,-1). Each symbol represents a combination of two bits, where one pair of bits represents the in-phase component and the other pair represents the quadrature component.

    4-PSK (4-Phase Shift Keying): 4-PSK is a more general term that refers to any Phase Shift Keying modulation with 4 different phase shifts. This could include QPSK as a specific case. However, 4-PSK might also refer to modulation schemes where each symbol represents only one bit of data, unlike QPSK where each symbol represents 2 bits. In a 4-PSK constellation, there are still four points, but they might not correspond to the same bit combinations as in QPSK.

So, while QPSK is a specific form of 4-PSK, not all 4-PSK schemes are QPSK. The distinction lies in how many bits each symbol represents and how the phase shifts are utilized.

 

People are good at skipping over material they already know!

View Related Topics to







Admin & Author: Salim

profile

  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

MATLAB code for MSK

 Copy the MATLAB Code from here % The code is developed by SalimWireless.com clc; clear; close all; % Define a bit sequence bitSeq = [0, 1, 0, 0, 1, 1, 1, 0, 0, 1]; % Perform MSK modulation [modSignal, timeVec] = modulateMSK(bitSeq, 10, 10, 10000); % Plot the modulated signal subplot(2,1,1); samples = 1:numel(bitSeq); stem(samples, bitSeq); title('Original message signal'); xlabel('Time (s)'); ylabel('Amplitude'); % Plot the modulated signal subplot(2,1,2); samples = 1:10000; plot(samples / 10000, modSignal(1:10000)); title('MSK modulated signal'); xlabel('Time (s)'); ylabel('Amplitude'); % Perform MSK demodulation demodBits = demodMSK(modSignal, 10, 10, 10000); % Function to perform MSK modulation function [signal, timeVec] = modulateMSK(bits, carrierFreq, baudRate, sampleFreq) % Converts a binary bit sequence into an MSK-modulated signal % Inputs: % bits - Binary input sequence % carrierFreq - Carri...

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

Modulation Constellation Diagrams BER vs. SNR BER vs SNR for M-QAM, M-PSK, QPSk, BPSK, ... 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 refers to the signal-to-noise power ratio. For ease of calculation, we commonly convert it to dB or decibels.   What is Signal the signal-to-noise ratio (SNR)? SNR = signal power/noise power (SNR is a ratio of signal power to noise power) SNR (in dB) = 10*log(signal power / noise power) [base 10] For instance, the SNR for a given communication system is 3dB. So, SNR (in ratio) = 10^{SNR (in dB) / 10} = 2 Therefore, in this instance, the s...

Constellation Diagrams of ASK, PSK, and FSK

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 SNR (dB): 15 Add AWGN Noise Modulation Type BPSK BFSK ...

Fundamentals of Channel Estimation

Channel Estimation Techniques Channel Estimation is an auto-regressive process that may be performed with a number of iterations. There are commonly three types of channel estimation approaches. 1. Pilot estimation  2. Blind estimation  3. Semi-blind estimation. For Channel Estimation,  CIR [↗] is used. The amplitudes of the impulses decrease over time and are not correlated. For example, y(n) = h(n) * x(n) + w(n) where y(n) is the received signal, x(n) is the sent signal, and w(n) is the additive white gaussian noise At the next stage, h(n+1) = a*h(n) + w(n) The channel coefficient will be modified as stated above at the subsequent stage. The scaling factor "a" determines the impulse's amplitude, whereas "h(n+1)" represents the channel coefficient at the following stage. Pilot Estimation Method To understand how a communication medium is currently behaving, a channel estimate is necessary. In order to monitor a channel's behavior in practice communication ...

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

Modulation ASK, FSK & PSK Constellation MATLAB Simulink MATLAB Code Comparisons among ASK, PSK, and FSK    Comparisons among ASK, PSK, and FSK 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. Bandwidth Calculator for ASK, FSK, and PSK The baud rate represents the number of symbols transmitted per second Select Modulation Type: ASK...

Constellation Diagram of FSK in Detail

  Binary bits '0' and '1' can be mapped to 'j' and '1' to '1', respectively, for Baseband Binary Frequency Shift Keying (BFSK) . Signals are in phase here. These bits can be mapped into baseband representation for a number of uses, including power spectral density (PSD) calculations. For passband BFSK transmission, we can modulate signal 'j' with a lower carrier frequency and signal '1' with a higher carrier frequency while transmitting over a wireless channel. Let's assume we are transmitting carrier signal fc1 for the transmission of binary bit '1' and carrier signal fc2 for the transmission of binary bit '0'. Simulator for 2-FSK Constellation Diagram Simulator for 2-FSK Constellation Diagram SNR (dB): 15 Add AWGN Noise Run Simulation ...

Gaussian minimum shift keying (GMSK)

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 NRZ signal over time to produce a continuous phase signal: θ(t) = ∫ 0 t m filtered (Ï„) dÏ„ This integration is crucial for avoiding abrupt phase transitions, ensuring smooth and continuous phase changes. Phase Modulation The next step involves using the phase signal to modulate a high-frequency carrier wave: s(t) = cos(2Ï€f c t + θ(t)) Here, f c is the carrier frequency, and s(t) represents the continuous-phase modulated carrier wave. Quadrature Modulation (Optional) ...