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Frequency-division multiplexing

About: Frequency-division multiplexing is a research topic. Over the lifetime, 5417 publications have been published within this topic receiving 126111 citations. The topic is also known as: FDM.


Papers
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Proceedings ArticleDOI
18 Nov 1996
TL;DR: A new loading algorithm for discrete multitone transmission is proposed, where rate is not distributed according to channel capacity, but rate and transmit power are assigned to maximize the signal-to-noise ratio in each carrier.
Abstract: A new loading algorithm for discrete multitone transmission is proposed. Thereby rate is not distributed according to channel capacity, but rate and transmit power are assigned to maximize the signal-to-noise ratio in each carrier. Because closed form expressions can be derived the algorithm is of very low complexity, even lower than the loading algorithm recently proposed by Chow et al. (see IEEE Transactions on Communications, no.2/3/4, p.773-5, 1995). Nevertheless achievable performance is higher or at least the same. Results for a typical high rate transmission over twisted pair lines are presented.

564 citations

Proceedings ArticleDOI
25 Jul 1995
TL;DR: The article examines the effects of ICI through analysis and simulation, in the context of a system design for HDTV digital video broadcasting to mobile receivers, showing that ICI can be modeled as an additive Gaussian random process that leads to an error floor which can be determined analytically as a function of the Doppler frequency.
Abstract: Orthogonal frequency division multiplexing with a suitably chosen guard interval is an effective means of eliminating intersymbol interference for high-rate transmission over fading dispersive channels. Time variations of the channel, however, lead to a loss of subchannel orthogonality, resulting in interchannel interference (ICI). The article examines the effects of ICI through analysis and simulation, in the context of a system design for HDTV digital video broadcasting to mobile receivers. It is shown that ICI can be modeled as an additive Gaussian random process that leads to an error floor which can be determined analytically as a function of the Doppler frequency. Antenna diversity and trellis coding are then examined as methods for reducing this error floor.

522 citations

Journal ArticleDOI
TL;DR: In this article, the performance of radio over fiber (RoF) links using low-cost optoelectronic components is assessed for distributed antenna applications in next generation wireless systems Important design issues are discussed and an example link design is presented for a wireless system requiring the transmission of four radio channels per link direction, each with 100 MHz bandwidth, modulation complexity of 256-QAM and 2048 OFDM subcarriers.
Abstract: The performance of radio over fiber (RoF) links using low cost optoelectronic components is assessed for distributed antenna applications in next generation wireless systems Important design issues are discussed and an example link design is presented for a wireless system requiring the transmission of four radio channels per link direction, each with 100 MHz bandwidth, modulation complexity of 256-QAM and 2048 OFDM subcarriers We show that the noise introduced by the RoF links does not have a significant impact on wireless range, provided the wireless system has uplink power control Finally, we compare the cost and performance of RoF links for this application with alternative link types that use digitized radio transmission and show that RoF is the optimum choice from a cost perspective

503 citations

Proceedings ArticleDOI
26 Apr 2009
TL;DR: GFDM enables frequency and time domain multi-user scheduling comparable to OFDM and provides an efficient alternative for white space aggregation even in heavily fragmented spectrum regions.
Abstract: This paper presents the GFDM system, a generalized digital multi-carrier transceiver concept. GFDM is based on traditional filter bank multi-branch multi- carrier concepts which are now implemented digitally. Our GFDM approach exhibits some attractive features which are of particular importance for scenarios exhibiting high degrees of spectrum fragmentation. Spectrum fragmentation is a typical technical challenge of digital dividend use cases, exploiting spectrum white spaces in the TV UHF bands which are located in close proximity to allocated spectrum. Specifically, the GFDM features are a lower PAPR compared to OFDM, a ultra-low out-of- band radiation due adjustable Tx-filtering and last but not least a block-based transmission using cyclic prefix insertion and efficient FFT-based equalization. GFDM enables frequency and time domain multi-user scheduling comparable to OFDM and provides an efficient alternative for white space aggregation even in heavily fragmented spectrum regions.

494 citations

Journal ArticleDOI
TL;DR: Simulation results have confirmed that the utility-based cross-layer optimization can significantly enhance the system performance and guarantee fairness and the gains come from multiuser diversity, frequency diversity, as well as time diversity.
Abstract: We have established a theoretical framework for cross-layer optimization in orthogonal frequency division multiplexing (OFDM) wireless networks. In this paper, we focus on effective and practical algorithms for efficient and fair resource allocation in OFDM wireless networks. We have taken various conditions into account and developed a variety of efficient algorithms, including sorting-search dynamic subcarrier assignment, greedy bit loading, and power allocation, as well as objective aggregation algorithms. We have also modified those algorithms for a certain type of nonconcave utility functions. To further improve performance by exploiting time diversity, a low-pass time filter can be easily incorporated into all of the algorithms. Simulation results have confirmed that the utility-based cross-layer optimization can significantly enhance the system performance and guarantee fairness. The gains come from multiuser diversity, frequency diversity, as well as time diversity. The fairness is automatically achieved by the behavior of marginal utility functions.

488 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202310
202224
2021136
2020222
2019239
2018251