These advanced cellular technologies, based on dual

frequency-division multiplexing and operating at 6GHz antenna frequency to support the channel density and data rates demanded by modern digital lifestyles, can be highly vulnerable to background noise and distortion caused by unwanted effects such as passive intermodulation (PIM).

Their topics include fundamentals of optical wireless communications, analyses of indoor optical wireless channels based on channel impulse responses, orthogonal

frequency-division multiplexing for indoor optical wireless communication, wireless solutions for aircraft based on optical wireless communication and power line communications, and multi-spot diffusing transmitters using holographic diffusers for infrared beams and receivers using holographic mirrors.

The DOCSIS 3.1 standard addresses the need for higher data bandwidth services with the addition of high capacity orthogonal

frequency-division multiplexing (OFDM) channels over the existing cable network.

Many communication systems employ

frequency-division multiplexing (FDM), in which multiple channels are frequency-translated to different sub-carriers to form a wideband composite signal at the transmitter.

It is also spectrum mask compliant up to 28.5 dBm for 802.11b/g communication, and utilizes Orthogonal

Frequency-Division Multiplexing (OFDM) to correct severe channel conditions without the need for complex equalization filters.

This combination is critical as DOCSIS 3.1 relies on orthogonal

frequency-division multiplexing (OFDM) to improve spectral efficiency, allowing a 50% increase in data rates up to 10Gb/s downstream and 1Gb/s upstream.

In the physical layer design, the two techniques adopt orthogonal frequency division multiplexing access (OFDMA) and discrete Fourier transform spread orthogonal

frequency-division multiplexing (DFTS OFDM).

Coherent-optical orthogonal

frequency-division multiplexing (CO-OFDM) and Nyquist wavelength-division multiplexing (WDM) maximize the spectral efficiency by packing neighbouring channels at symbol rate spacing.

A multiband Software Defined Radar based on orthogonal

frequency-division multiplexing technique is proposed in this work for an accurate soil discontinuities detection, taking into account also the dispersive behavior of media.

Electrical engineers Chiueh (National Taiwan U.), Pei-Yun Tsai (National Central U., Taiwan), and joining for the second edition I-Wei Lai (Academia Sinica, Taiwan) update the 2007 first edition by integrating multiple-input-multiple-output (MIMO) techniques into their explanation of orthogonal

frequency-division multiplexing (OFDM), the favorite modulation technology for wireless communication systems.

Ebert, "Data Transmission by

Frequency-Division Multiplexing Using the Discrete Fourier Transform", IEEE Transactions on Communication Technology, vol.