orthogonal frequency-division multiplexing (OFDM)

Orthogonal frequency-division multiplexing (OFDM) is a method of digital signal modulation in which a single data stream is split across several separate narrowband channels at different frequencies to reduce interference and crosstalk. The original data stream bits -- that in a conventional single-channel modulation scheme would be sent serially (one after the other) -- are transmitted in parallel (several at once on separate channels) but at lower speed in each substream (a stream within another stream) relative to the original signal. This means symbols sent in the substreams are longer and spaced farther apart. In the original stream, each bit might be represented by a 1-nanosecond (ns) segment of the signal, with 0.25 ns spacing between bits. Splitting the signal across four component streams lets each bit be represented by 4 ns of the signal with 1ns spacing between. This reduces interference among symbols and makes it easier to receive each symbol accurately while maintaining the same throughput (in this example, 4 bits every 5 ns).

Download this free guide

How SD-WAN Can Help Enable Digital Transformation

When embarking on digital transformation initiatives, its important to factor in WAN design to avoid poor application performance and customer dissatisfaction. In this white paper, you’ll explore the drawbacks of traditional WAN architectures and how a managed SD-WAN service can overcome some of these challenges.

Start Download

• Corporate E-mail Address:

  You forgot to provide an Email Address.

  This email address doesn’t appear to be valid.

  This email address is already registered. Please login.

  You have exceeded the maximum character limit.

  Please provide a Corporate E-mail Address.

• • I agree to TechTarget’s Terms of Use, Privacy Policy, and the transfer of my information to the United States for processing to provide me with relevant information as described in our Privacy Policy.

  Please check the box if you want to proceed.

• • I agree to my information being processed by TechTarget and its Partners to contact me via phone, email, or other means regarding information relevant to my professional interests. I may unsubscribe at any time.

  Please check the box if you want to proceed.

By submitting my Email address I confirm that I have read and accepted the Terms of Use and Declaration of Consent.

OFDM technology was first conceived of in the 1960s and 1970s during research into minimizing interference among channels near each other in frequency and to achieve clean data transmission in situations prone to interference and signal corruption when more conventional modulation schemes are used.

OFDM is used in Wi-Fi, DSL internet access, 4G wireless communications, and digital television and radio broadcast services.