Results 81 to 90 of about 34,306 (214)

Spatial transmit diversity techniques for broadband OFDM systems [PDF]

, 2000
— In this paper, we investigate different spatial transmit diversity concepts for orthogonal frequency division multiplexing (OFDM) systems. The idea is to artificially increase the frequency and time selectivity of the resulting channel transfer ...
Stefan Kaiser
core  

Unified Model and Survey on Modulation Schemes for Next-Generation Automotive Radar Systems

Remote Sensing
Commercial automotive radar systems for advanced driver assistance systems (ADASs) have relied on frequency-modulated continuous wave (FMCW) waveforms for years due to their low-cost hardware, simple signal processing, and established academic and ...
Moritz Kahlert, Tai Fei, Yuming Wang, Claas Tebruegge, Markus Gardill   +4 more
doaj   +1 more source

Research on modified selected mapping technique for PAPR reduction and reception performance improvement in 8QAM-OFDM optical access systems

Journal of the European Optical Society-Rapid Publications, 2017
Background Orthogonal frequency division multiplexing has been regarded as one of the promising technologies for the optical access systems application.
Yufeng Shao, Wenzhe Ma
doaj   +1 more source

Orthogonal frequency division multiplexing (OFDM) in photonic communications

, 2010
OFDM has emerged as a promising modulation technique in long-haul and access optical networks because of a number of advantages: Scalable spectrum partitioning, good spectral efficiency, dispersion tolerance, and a natural suitability for software-defined transmission.
Freude, W., Hillerkuss, D., Schellinger, T., Schmogrow, R., Winter, M., Vallaitis, T., Bonk, R., Marculescu, A., Li, J., Dreschmann, M., Meyer, J., Ben Ezra, S., Narkiss, N., Nebendahl, B., Parmigiani, F., Petropoulos, P., Resan, B., Weingarten, K., Ellermeyer, T., Lutz, J., Möller, M.   +20 more
openaire   +1 more source

Метод прихованої передачі інформації в системах з Orthogonal frequency division multiplexing (OFDM) модуляцією

Наука і техніка Повітряних Сил Збройних Сил України, 2021
У статті проаналізовано можливості використання сигналів з Orthogonal frequency division multiplexing (OFDM) модуляцією для організації скритного радіозв’язку в системах спеціального призначення. Побудовано та проаналізовано “образ” сигналу з OFDM модуляцією в псевдофазовому просторі.
openaire   +3 more sources

Extremely low frequency based communication link [PDF]

, 2009
The paper discusses the literature review and the possibility of using the ground itself as transmission medium for various users’ transceivers and an administrator transceiver using Multi-Carrier-Direct Sequence-Code Division Multiple Access (MC-DS-CDMA)
Alaiwi, A, Holmes, Violeta, Mather, Peter, Sibley, Martin J.N.   +3 more
core  

Channel estimation using neural network in Orthogonal Frequency Division Multiplexing-Interleave Division Multiple Access (OFDM-IDMA) system

2014 International Telecommunications Symposium (ITS), 2014
In this paper, channel estimation based on neural network trained by Levenberg-Marquardt Algorithm is proposed to estimate the channel coefficients in Orthogonal Frequency Division Multiplexing-Interleave Division Multiple Access (OFDM-IDMA) systems. Conventional pilot based channel estimation algorithms like Minimum Mean Square Error (MMSE) and Least ...
TAŞPINAR, NECMİ, Simsir, Sakir
openaire   +3 more sources

Carrier Frequency Offset Effects on OFDM System over Rayleigh Fading Channel

Journal of Electrical, Electronics and Informatics, 2019
Orthogonal Frequency Division Multiplexing (OFDM) system showed the use of Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) to perform the baseband modulation and demodulation.
N. M. A. E. Dewi Wirastuti, I.G.A.K. Diafari Djuni Hartawan, I Made Arsa Suyadnya, Duman Care Khrisne   +3 more
doaj   +1 more source

Modulation Schemes for Cognitive Radio in White Spaces [PDF]

, 2010
In this paper we give an overview and a comparison of the possible waveforms for white space applications. Four physical layer schemes for cognitive radio are selected for study: Orthogonal Frequency Division Multiplexing (OFDM), DFT-Spread OFDM (DFTS ...
Horvath, P., Kollar, Zs.
core   +1 more source

Downlink Precoding for Massive MIMO Systems Exploiting Virtual Channel Model Sparsity

, 2017
In this paper, the problem of designing a forward link linear precoder for Massive Multiple-Input Multiple-Output (MIMO) systems in conjunction with Quadrature Amplitude Modulation (QAM) is addressed.
Ayanoglu, Ender, Ketseoglou, Thomas
core   +1 more source