In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission used in digital modulation for encoding digital (binary) data on multiple carrier frequencies.

OFDM avoids interference and makes it easier to receive data accurately while maintaining the same throughput by transmitting data parallelly across multiple carriers (or channels) within the OFDM signal. For example, Wi-Fi 5 used 52 data-carrying sub-carriers, while Wi-Fi 6 uses 234.

DOCSIS 3.1 downstream orthogonal frequency division multiplexing (OFDM) signals support a variety of modulation orders up to 4096-QAM (optionally as high as 8192-QAM and 16384-QAM) over channel bandwidths ranging from a minimum of 24 MHz to a maximum of 192 MHz.

Orthogonal frequency-division multiplexing (OFDM) is a method of data transmission where a single information stream is split among several closely spaced narrowband subchannel frequencies instead of a single wideband channel frequency.

2024年2月13日 · In this application note we will delve into the basic characteristics of OFDM, first defining what is meant by orthogonal, then examining how OFDM systems structure their transmissions in both the time and frequency domains.

Orthogonal Frequency Division Multiplexing (OFDM) is a digital multi-carrier modulation scheme that extends the concept of single subcarrier modulation by using multiple subcarriers within the same single channel.

OFDM is used in the downstream and is a common channel shared by all compatible cable modems. OFDMA is used in the upstream by cable modems transmitting data to the CMTS.

2021年10月5日 · Orthogonal frequency-division multiplexing (OFDM) is a method of digital modulation in which a signal is split into several narrowband channels at different frequencies. The traditional...

OFDMA allows per-channel or per-subchannel power and lower maximal transmission power for low-data-rate users, eliminating pulsed carriers and conserving battery life in devices.

FDM Introduction: Orthogonal Frequency Division Multiplexing (OFDM) is a digital multi-carrier modulation scheme that extends the concept of single subcarrier modulation by using multiple subcarriers within the sa.

2020年4月16日 · Mobile wireless systems employ OFDM to achieve high bandwidth channels. Existing 4G (LTE) mobile wireless uses OFDM for the downlink (base station to mobile device), with a fixed subcarrier spacing of 15 kHz.

2023年2月20日 · OFDM is a principle where the available bandwidth is divided into multiple sub-carriers, each having a narrow bandwidth. Thus, the symbol bandwidth is also reduced compared to the single carrier scheme. This increases the symbol time.

2017年5月1日 · OFDM is the technology behind many high speed systems such as WiFi (IEEE 802.11a, g, n, ac), WiMAX (IEEE 802.16), 4G and 5G mobile communications (LTE). A close cousin, Discrete Multi-tone (DMT), is used in ADSL and powerline communication systems.

Version 3.1 of DOCSIS specifications, an international telecommunications standard for cable TV systems, introduces downstream Orthogonal Frequency Division Multiplexing (OFDM) channels, which are highly flexible in terms of frequency, bandwidth, modulation type, and active spectrum.

2019年10月7日 · In data communications and networking, orthogonal frequency-division multiplexing (OFDM) is a method of digital data modulation, whereby a single stream of data is divided into several separate sub-streams for transmission via multiple channels.

2019年2月26日 · Orthogonal Frequency Division Multiplexing (OFDM) is a key wideband digital communication method used in wireless transmission. Data is split into several streams and transmitted on multiple narrowband channels to reduce interference and crosstalk.

2011年5月24日 · OFDM is a multicarrier modulation technique, which employs several carriers, within the allocated bandwidth, to convey the information from source to destination. Each carrier may employ one of the several available digital modulation techniques (BPSK, …

2015年4月22日 · OFDM: Orthogonal Frequency Division Multiplexing, is a form of signal modulation that divides a high data rate modulating stream placing them onto many slowly modulated narrowband close-spaced subcarriers, and in this way is less sensitive to frequency selective fading.

To understand the basics of OFDM, let's start with the Fourier tranform pair of a rectangular function and a sinc function: Because sinc(1)= 0 sinc (1) = 0, the minimum positive f that satisfies X (f) = 0 is Δf =1/τ Δ f = 1 / τ, where τ τ equals the duration of the rectangular function.

4 天之前 · In OFDM, the data for transmission is, via a serial to parallel converter, converted into several parallel streams, and each stream used to modulate a separate subcarrier. Thus, only a small amount of the total data is transmitted via each subcarrier, in a subchannel a fraction of the width of the total channel.

OFDM, or Orthogonal Frequency-Division Multiplexing, is a digital communication technique that transmits data by splitting it across multiple narrowband channels or sub-carriers within a broader frequency band. By doing so, OFDM allows for high data rates and efficient use of …

To propose novel solutions for accurate channel estimation in MIMO-OFDM systems, we dive deep into the theoretical analysis of different channel estimation techniques.

2025年3月18日 · Frequency-modulated continuous wave (FMCW) and orthogonal frequency-division multiplexing (OFDM) technologies play significant roles in millimeter-wave radar and communication. Their combinations, however, are understudied in the literature. This paper introduces a novel OFDM-FMCW dual-functional radar-communications (DFRC) system that …