Skip to main content

FBMC vs FDM vs OFDM: Complete Comparison


FBMC vs FDM vs OFDM: Complete Comparison

A detailed comparison of FBMC, FDM, and OFDM waveforms covering spectral efficiency, orthogonality, multipath handling, and applications in modern wireless systems.

1. Basics and Concepts

Technique Full Form Concept
FDM Frequency Division Multiplexing Divides spectrum into non-overlapping bands; requires guard bands to avoid interference.
OFDM Orthogonal Frequency Division Multiplexing Uses orthogonal subcarriers allowing spectral overlap without interference.
FBMC Filter Bank Multicarrier Uses filtered subcarriers for excellent spectral containment and real-domain orthogonality.

2. Key Characteristics

  • Spectral Efficiency: FDM (low), OFDM (high), FBMC (very high)
  • Filtering: FDM uses bandpass filters, OFDM uses rectangular pulses, FBMC uses prototype filters
  • Orthogonality: FDM via separation, OFDM over symbol duration, FBMC in real domain
  • Multipath: FDM poor, OFDM uses cyclic prefix, FBMC handles ISI without CP
  • Complexity: FDM low, OFDM medium, FBMC high

FDMA vs FBMC Packets: Real Examples and Mathematics

1. FDMA Packets

FDMA assigns each user a separate frequency band. Each packet occupies a fixed frequency slot over time.

Mathematical Representation


x_k(t) = ∑ s_k[n] · rect((t − nT)/T) · e^{j2Ļ€f_k t}
  • rect(·) is a rectangular pulse of duration T
  • sā‚–[n] is the n-th symbol of user k
  • eŹ²²Ļ€fā‚–t is the carrier

Graphical Idea


| User1: 1kHz |      |      |
| User2: 2kHz     |      |
| User3: 3kHz         |  |

2. FBMC Packets

FBMC uses filtered subcarriers allowing frequency overlap while suppressing interference.

Mathematical Representation


x(t) = ∑ ∑ s_m[n] · g(t − nT) · e^{j2Ļ€mĪ”f t}
  • g(t) is a smooth prototype filter
  • Ī”f = 1/T is subcarrier spacing

Conceptual View


| Sub0 |~~~~~~|
| Sub1   |~~~~~~|
| Sub2     |~~~~~~|

Subcarriers overlap in frequency but remain orthogonal due to filtering.

Guard Bands in FDMA

Guard bands are frequency gaps, not zero-padding in time.

User Assigned Band Guard Band
1 0–1 kHz 1–1.2 kHz
2 1.2–2.2 kHz 2.2–2.4 kHz

FBMC reduces or eliminates guard bands using spectral shaping.

Final Summary

  • FDM is simple but spectrally inefficient.
  • OFDM balances efficiency and complexity using cyclic prefix.
  • FBMC offers the best spectral containment for future wireless systems.

Contact Us

Name

Email *

Message *

Popular Posts

BER vs SNR for M-ary QAM, M-ary PSK, QPSK, BPSK, ...(MATLAB Code + Simulator)

Bit Error Rate (BER) & SNR Guide Analyze communication system performance with our interactive simulators and MATLAB tools. šŸ“˜ Theory šŸ§® Simulators šŸ’» MATLAB Code šŸ“š Resources BER Definition SNR Formula BER Calculator MATLAB Comparison šŸ“‚ Explore M-ary QAM, PSK, and QPSK Topics ▼ šŸ§® Constellation Simulator: M-ary QAM šŸ§® Constellation Simulator: M-ary PSK šŸ§® BER calculation for ASK, FSK, and PSK šŸ§® Approaches to BER vs SNR What is Bit Error Rate (BER)? The BER indicates how many corrupted bits are received compared to the total number of bits sent. It is the primary figure of merit f...
Read more

UGC NET Electronic Science Previous Year Question Papers with Solutions

Home / Engineering & Other Exams / UGC NET 2022 PYQ ⬇️ Download Papers and Solutions šŸ“‹ Exam Pattern šŸ’” Preparation Tips ❓ FAQs šŸ“„ Download UGC NET Electronics PDFs Complete collection of previous year question papers, answer keys and explanations for Subject Code 88. Start Downloading UGC-NET (Electronics Science, Subject code: 88) Subject_Code : 88; Department : Electronic Science; šŸ“‚ View All Question Papers Q. UGC Net Electronic Science Question Paper [June 2025] A. UGC Net Electronic Science Question Paper With Answer Key Download Pdf [June 2025] with full explanation Q. UGC Net Electronic Science Question Paper [December 2024] A. UGC Net Electronic Science Question Paper With Answer Key Download Pdf [December 2024] ...
Read more

Constellation Diagrams of ASK, PSK, and FSK (with MATLAB Code + Simulator)

Constellation Diagrams: ASK, FSK, and PSK Comprehensive guide to signal space representation, including interactive simulators and MATLAB implementations. šŸ“˜ Overview šŸ§® Simulator ⚖️ Theory Q-function šŸ“š Resources šŸ“‚ Other Topics: M-ary PSK & QAM Diagrams ▼ šŸ§® Simulator for M-ary PSK Constellation šŸ§® Simulator for M-ary QAM Constellation 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 phas...
Read more

MATLAB Code for ASK, FSK, and PSK (with Online Simulator)

MATLAB Code for ASK, FSK, and PSK Comprehensive implementation of digital modulation and demodulation techniques with simulation results. šŸ“˜ Theory šŸ“” ASK Code šŸ“¶ FSK Code šŸŽš️ PSK Code šŸ•¹️ Simulator šŸ“š Further Reading Amplitude Shift Frequency Shift Phase Shift Live Simulator ASK, FSK & PSK HomePage MATLAB Code MATLAB Code for ASK Modulation and Demodulation COPY % The code is written by SalimWireless.Com clc; clear all; close all; % Parameters Tb = 1; fc = 10; N_bits = 10; Fs = 100 * fc; Ts = 1/Fs; samples_per_bit = Fs * Tb; rng(10); binar...
Read more

Online Simulator for ASK, FSK, and PSK

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. šŸ“” ASK Simulator šŸ“¶ FSK Simulator šŸŽš️ BPSK Simulator šŸ“š More Topics ASK Modulator FSK Modulator BPSK Modulator More Topics 1. ASK (Amplitude Shift Keying) Simulat...
Read more

MATLAB code for BER vs SNR for M-QAM, M-PSK, QPSk, BPSK, ...(with Online Simulator)

šŸ§® MATLAB Code for BPSK, M-ary PSK, and M-ary QAM Together šŸ§® MATLAB Code for M-ary QAM šŸ§® MATLAB Code for M-ary PSK šŸ“š Further Reading MATLAB Script for BER vs. SNR for M-QAM, M-PSK, QPSK, BPSK % Written by Salim Wireless clc; clear; close all; snr_db = -5:2:25; psk_orders = [2, 4, 8, 16, 32]; qam_orders = [4, 16, 64, 256]; ber_psk_results = zeros(length(psk_orders), length(snr_db)); ber_qam_results = zeros(length(qam_orders), length(snr_db)); for i = 1:length(psk_orders) ber_psk_results(i, :) = berawgn(snr_db, 'psk', psk_orders(i), 'nondiff'); end for i = 1:length(qam_orders) ber_qam_results(i, :) = berawgn(snr_db, 'qam', qam_orders(i)); end figure; semilogy(snr_db, ber_psk_results(1, :), 'o-', 'LineWidth', 1.5, 'DisplayName', 'BPSK'); hold on; for i = 2:length(psk_orders) semilogy(snr_db, ber_psk_results(i, :), 'o-', 'DisplayName', sprintf('%d-PSK', psk_or...
Read more

BER performance of QPSK with BPSK, 4-QAM, 16-QAM, 64-QAM, 256-QAM, etc (MATLAB + Simulator)

šŸ“˜ Overview šŸ“š QPSK vs BPSK and QAM: A Comparison of Modulation Schemes in Wireless Communication šŸ“š Real-World Example šŸ§® MATLAB Code šŸ“š Further Reading   QPSK provides twice the data rate compared to BPSK. However, the bit error rate (BER) is approximately the same as BPSK at low SNR values when gray coding is used. On the other hand, QPSK exhibits similar spectral efficiency to 4-QAM and 16-QAM under low SNR conditions. In very noisy channels, QPSK can sometimes achieve better spectral efficiency than 4-QAM or 16-QAM. In practical wireless communication scenarios, QPSK is commonly used along with QAM techniques, especially where adaptive modulation is applied. Modulation Bits/Symbol Points in Constellation Usage Notes BPSK 1 2 Very robust, used in weak signals QPSK 2 4 Balanced speed & reliability 4-QAM ...
Read more

Q-function in BER vs SNR Calculation

Q-function in BER vs. SNR Calculation In the context of Bit Error Rate (BER) and Signal-to-Noise Ratio (SNR) calculations, the Q-function plays a significant role, especially in digital communications and signal processing . What is the Q-function? The Q-function is a mathematical function that represents the tail probability of the standard normal (Gaussian) distribution. Specifically, it is defined as: Q(x) = (1 / sqrt(2Ļ€)) ∫ā‚“∞ e^(-t² / 2) dt In simpler terms, the Q-function gives the probability that a standard normal random variable exceeds a value x . It is the complementary cumulative distribution function (CCDF) of the standard Gaussian distribution. The Role of the Q-function in BER vs. SNR The Q-function is the standard tool for calculating the Bit Error Rate (BER) in digital communication systems like Binary Phase Shift Keying (BPSK) or Quadrature Phase Shift Keying (QPSK) , where noise follows a Gaussian dis...
Read more