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Artículos de revistas sobre el tema "Time-Frequency fading"

Autor: Grafiati

Publicado: 25 de mayo de 2024

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1

Zhiqiang Liu, Yan Xin, and G. B. Giannakis. "Space-time-frequency coded OFDM over frequency-selective fading channels." IEEE Transactions on Signal Processing 50, no. 10 (2002): 2465–76. http://dx.doi.org/10.1109/tsp.2002.803332.

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2

Hongbin Li. "Differential space-time-frequency modulation over frequency-selective fading channels." IEEE Communications Letters 7, no. 8 (2003): 349–51. http://dx.doi.org/10.1109/lcomm.2003.814711.

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3

ISHII, K. "Space-Time-Frequency Turbo Code over Time-Varying and Frequency-Selective Fading Channel." IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences E88-A, no. 10 (2005): 2885–95. http://dx.doi.org/10.1093/ietfec/e88-a.10.2885.

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4

Chu, James. "Frequency-Selective and Time-Selective Fading [Book\/Software Reviews]." IEEE Microwave Magazine 19, no. 5 (2018): 87–103. http://dx.doi.org/10.1109/mmm.2018.2821089.

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5

TAO, X., C. ZHANG, J. LU, and N. SUEHIRO. "Adaptive CI-OSDM in Time-Frequency Selective Fading Channel." IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences E91-A, no. 12 (2008): 3712–22. http://dx.doi.org/10.1093/ietfec/e91-a.12.3712.

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6

Borah, D. K., and B. D. Hart. "Receiver structures for time-varying frequency-selective fading channels." IEEE Journal on Selected Areas in Communications 17, no. 11 (1999): 1863–75. http://dx.doi.org/10.1109/49.806817.

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7

Al-nahari, A. Y., F. E. Abd El-Samie, and M. I. Dessouky. "Distributed Space-Time/Frequency Coding Schemes for Single-Carrier Frequency Division Multiple Access Systems." ISRN Communications and Networking 2011 (April 4, 2011): 1–10. http://dx.doi.org/10.5402/2011/549706.

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The single carrier-frequency division multiple access (SC-FDMA) system is a new system that was adopted in the standardization of the upcoming 3GPP long-term evolution (LTE). Designing diversity-achieving schemes for the SC-FDMA system is a challenging task. The codes adopted should not affect the peak-to-average power ratio (PAPR) among other constraints. In this paper, we consider the design of cooperative diversity schemes for SC-FDMA systems in the uplink direction. Specifically, two relay-assisted distributed space-time/frequency codes are proposed. The proposed distributed space-frequency code (SFC) achieves full spatial diversity in the uplink fast-fading channels, where a diversity of order three can be achieved. The proposed code keeps a low PAPR, which is a good feature of the system. A minimum mean square error (MMSE) decoder is used at the receiver of the destination node. Moreover, we propose a bandwidth-efficient distributed space-time code (STC) for slow-fading relay channels. A decode-and-forward (DF) protocol is used at the relay node, and the possibility of erroneous decoding is taken into account. Simulation results demonstrate the performance improvement of the proposed schemes.

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8

Sun, Zeng You, and Xia Ling. "Time-Varying Channel Multi-Carrier Modulation Technology Research." Applied Mechanics and Materials 513-517 (February 2014): 2680–86. http://dx.doi.org/10.4028/www.scientific.net/amm.513-517.2680.

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With frequency selective fading from multi-path characteristic and time selective fading from high speed mobility, double selective channel has become the typical context for the current wireless communication system. To realize high performance transmission in time-varying channel, this paper presents DAFT-OFDM multicarrier modulation scheme. The simulation results show that the scheme is applicable to time-varying fading channel, in which each path experiences independent Doppler spread. The scheme can also reduce ICI effectively.

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9

Fokin, G. "Modeling multi-beam radio channel." Telecom IT 9, no. 1 (2021): 59–78. http://dx.doi.org/10.31854/2307-1303-2021-9-1-59-78.

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In this work, a simulation model of a radio channel with fading is implemented for use  in research of the multipath channel, as well as for assessing the noise immunity of transmission, recep-tion and processing systems in modern and future mobile communication and radio access networks. Formalization of mathematical models of a radio channel with fading, including the Rayleigh amplitude distribution, uniform phase distribution and a given Doppler spectrum, made it possible to visualize  the time-frequency and probabilistic characteristics of a radio channel with fading. The implementation  of the procedures for delaying and attenuating copies of signals in a multipath radio channel made it pos-sible to reproduce scenarios of flat and frequency selective fading, which are widely used in practice in assessing the noise immunity of signals with given frequency and time characteristics.

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10

Kim, Minhyuk, and Sekchin Chang. "A real-time locating system for localization of high-speed mobile objects." International Journal of Distributed Sensor Networks 14, no. 5 (2018): 155014771877447. http://dx.doi.org/10.1177/1550147718774475.

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This article addresses a novel real-time locating system for localization of high-speed mobile objects in fading environments. The proposed locating system exploits time difference of arrival measurements based on ultra-wideband signals. However, the ultra-wideband signals cause a frequency-selective fading due to their short time duration, which induces severe inter-symbol interference. Moreover, high-speed objects cause fast fading due to large Doppler spread. Therefore, the fading cases considerably reduce the localization performance. The presented locating system relies on a new localization approach in order to overcome the fading issues, which utilizes a modification of extended Kalman filtering. Especially, the suggested locating method works well even in the zero time difference of arrival case, which occurs due to a very deep fading. Experiment results verify that the proposed real-time locating system gives excellent localization performance in severe fading environments. The results also exhibit that the presented locating system is superior to the conventional locating systems in the localization of high-speed mobile objects under fading environments.

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11

Rainish, D., and J. M. Perl. "Generalized cutoff rate of time- and frequency-selective fading channels." IEEE Transactions on Communications 37, no. 5 (1989): 449–67. http://dx.doi.org/10.1109/26.24596.

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12

Tulino, Antonia M., Giuseppe Caire, Shlomo Shamai, and Sergio Verdu. "Capacity of Channels With Frequency-Selective and Time-Selective Fading." IEEE Transactions on Information Theory 56, no. 3 (2010): 1187–215. http://dx.doi.org/10.1109/tit.2009.2039041.

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13

Heider, Inaam Abbas. "Improvement of Fading Channel Modeling Performance for Wireless Channel." International Journal of Electrical and Computer Engineering (IJECE) 8, no. 3 (2018): 1451. http://dx.doi.org/10.11591/ijece.v8i3.pp1451-1459.

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Fading channel modeling is generally defined as the variation of the attenuation of a signal with various variables. Time, geographical position, and radio frequency which is included. Fading is often modeled as a random process. Thus, a fading channel is a communication channel that experiences fading. In this paper, the proposed system presents a new design and simulate a wireless channel using Rayleigh channels. Rayleigh channels using two approaches (flat and frequency-selective fading channels) in order to calculate some path space loss efforts and analysis the performance of different wireless fading channel modeling. The results show that the bite error rate (BER) performance is dramatically improved in the value of signal to noise ratio (SNR) is equal to 45dB. Finally, the experimental results show that the proposed method enhances the performance of fading channel modeling by reducing the error of BER when the SNR is reduced also. Moreover, the more accurate model is Rayleigh model which can be considered for developing fading channel model.

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14

Isaeva, E. A. "CONNECTION OF THE INTENSITY OF THE FLUX OF SCR PROTONS WITH THE VELOCITY OF THE CME AND WITH THE FADING OF THE RADIO EMISSION OF THE SUN IN THE DECAMETER RANGE." Odessa Astronomical Publications 34 (December 3, 2021): 76–80. http://dx.doi.org/10.18524/1810-4215.2021.34.244256.

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The relationship between SCR and CME and with fading of the continuum of noise storms and typeIV radio bursts in the decameter range is investigated. It was shown earlier that about 60% of CMEs associated with solar proton events are accompanied by deep fading of the solar radio emission in the decameter range, which coin-cides in time with CME registration. It has also been shown that fading is characterized by fading depth, the frequency bandwidth in which the fading occurs, as well as the duration of the fading and the frequency at which the maximum fading depth is observed. Further detailed studies have shown that for proton events accompanied by fading of the solar radio emission in the decameter range, the relationship between the intensity of the SCR proton flux and the CME velocity is much worse than for events without fading of the solar radio emission in the decameter range. However, it was foundthat for such events, the relationship between the flux of SCR protons and the CME velocity significantly increases if we take into account the fading depth of the solar radio emission in the decameter range.Earlier in (Isaeva, 2019), the results of a study of the relationship between the intensity of fading of the continuum of noise storms with the parameters of X-ray bursts, with the CME velocity and the velocity of coronal shock waves, as well as with the intensity of the SCR proton flux were presented. This paper presents the results of studying the relationship between the intensity of the SCR proton flux withthe parameters of type II and IV radio bursts, as well as with the CME velocity and with the velocity of coronal shock waves, depending on the intensity of fading of the solar radio emission in the decameter range at a frequency of 27 MHz. The frequency of 27 MHz was chosen because in the region of this frequency the maximum fading depth of the solar radio emission in the decameter range is observed.

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15

Diki Andriasmika, I. Wayan, I. G. A. K. Diafari Djuni H, and N. M. A. E. Dewi Wirastuti. "ANALISIS INTERCARRIER INTERFERENCE (ICI) SISTEM OFDM-MIMO STBC PADA KANAL FREQUENCY SELECTIVE FADING." Jurnal SPEKTRUM 6, no. 1 (2019): 90. http://dx.doi.org/10.24843/spektrum.2019.v06.i01.p13.

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Wireless telecommunications requires high-speed access. One technique used tooWireless telecommunications requires high-speed access. One technique used toovercome multipath fading is Ortoghonal Frequency Division Multiplexing (OFDM). Theweakness of OFDM occurs on the mobile channel due to time variations in the channel, givingrise to intercarrier interference (ICI). The aim of the study is to determine the effect ofnormalized carrier frequency offset on ICI and the effect of frequency selective fading tapchannel. The simulation results show the system performance in calculating the Eb / N0 5 dBvalue that the greater the normalized carrier frequency offset (?), the worse the signal. Thesimulation results show the OFDM-MIMO system performance in calculating the Eb / N0 5 dBvalue that the greater the tap on the channel the worse the signal.vercome multipath fading is Ortoghonal Frequency Division Multiplexing (OFDM). Theweakness of OFDM occurs on the mobile channel due to time variations in the channel, givingrise to intercarrier interference (ICI). The aim of the study is to determine the effect ofnormalized carrier frequency offset on ICI and the effect of frequency selective fading tapchannel. The simulation results show the system performance in calculating the Eb / N0 5 dBvalue that the greater the normalized carrier frequency offset (?), the worse the signal. Thesimulation results show the OFDM-MIMO system performance in calculating the Eb / N0 5 dBvalue that the greater the tap on the channel the worse the signal.

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16

Babich, Fulvio, Guido Montorsi, and Francesca Vatta. "Turbo Codes Performance Optimization over Block Fading Channels." Journal of Communications Software and Systems 2, no. 3 (2017): 228. http://dx.doi.org/10.24138/jcomss.v2i3.285.

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In this paper, the best achievable performance of a turbo coded system on a block fading channel is obtained, assuming binary antipodal modulation. A rate 1/3 turbo code is considered, obtained by concatenating, through a random interleaver, an 8-states rate 1/2 and a rate 1 convolutional codes (CC). The block fading channel model is motivated by the fact that in many wireless systems the coherence time of the channel is much longer than one symbol interval, resulting in adjacent symbols being affected by the same fading value. The fading blocks will experience independent fades, assuming a sufficient separation in time, in frequency, or both in time and in frequency. This channel model is suitable for analyzing, forinstance, wireless communication systems employing techniques such as slow frequency-hopping, as is done in the Global System for Mobile communications (GSM).In such systems, coded information is transmitted over a small number of fading channels in order to achieve diversity. The best coded information allocations over a certain number of fading channels are evaluated, using the Eades-McKay algorithm to generate distinct permutations of a multiset. Bounds on the achievable performance due to coding are derived using information-theoretic techniques. In particular, in the paper an analytical method is proposed, based on the sphere-packing bounding technique, to assess the achievable performance. Moreover, simulation results are obtained and compared with the theoretical ones.

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17

Ng, Benjamin K., and Chan-Tong Lam. "Single-Carrier Rotation-Interleaved Space-Time Code for Frequency-Selective Fading Channels." Applied Sciences 12, no. 24 (2022): 12803. http://dx.doi.org/10.3390/app122412803.

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A novel single-carrier-based space-time code construction scheme to exploit the advantages of a frequency-selective fading channel is investigated in this paper. The proposed construction scheme is based on multiplexing independent streams of phase-rotated space-time codes in a time-interleaved fashion. The advantage of such design is that it guarantees full space-time-multipath diversity by using traditional space-time codes or MIMO signaling schemes originally designed for flat fading channels as the constituent codes. Another advantage is that this approach incurs no loss in bandwidth efficiency and it alleviates the problem of high PAPR in OFDM-based space-time codes. By employing random or algebraic rotations, the design is potentially suitable for any number of transmit antennas or multipaths. The simulation results indicate that full space-time-multipath diversity is attained using this new approach, and comparisons with some existing space-time codes designed for frequency-selective channels are made to show its performance advantage.

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18

Mheidat, Hakam, Murat Uysal, and Naofal Al-Dhahir. "Quasi-Orthogonal Time-Reversal Space–Time Block Coding for Frequency-Selective Fading Channels." IEEE Transactions on Signal Processing 55, no. 2 (2007): 772–78. http://dx.doi.org/10.1109/tsp.2006.885766.

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19

Liu, Ning, Zhengyuan Xu, and Brian M. Sadler. "Ziv–Zakai Time-Delay Estimation Bounds for Frequency-Hopping Waveforms Under Frequency-Selective Fading." IEEE Transactions on Signal Processing 58, no. 12 (2010): 6400–6406. http://dx.doi.org/10.1109/tsp.2010.2068547.

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20

Pashintsev, V. P., D. A. Belokon, S. A. Koval, and A. D. Skorik. "Methodology for Estimating Communication Reliability in Shortwave Radio-Frequency Transmission Channels with Rician Fading Given Ionospheric Diffusivity." Journal of the Russian Universities. Radioelectronics 25, no. 6 (2022): 22–39. http://dx.doi.org/10.32603/1993-8985-2022-25-6-22-39.

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Introduction. There exists a technique for estimating the dependence of communication reliability in a shortwave radio-frequency transmission channel (SWRC) with a single discrete beam and diffuse wave scattering across small-scale ionospheric inhomogeneities on the selected operating frequency taking into account the given signal-to-noise ratio and ionospheric diffusivity. In this technique, the Nakagami m-distribution is used to describe interference fading of the received signal. However, in a single-beam SWRC, fading signal amplitudes are described by the Rician or generalized Rayleigh, rather than by Nakagami, distribution in 90 % of all cases. At the same time, the results obtained using the Nakagami distribution to approximate fading and to assess its effect on communication quality agrees well with those obtained by the Rician distribution only in two cases: the presence of Rayleigh distribution or the complete absence of fading.Aim. To develop a methodology for estimating communication reliability in a single-beam SWRC with Rician fading and to compare its results with that under Nakagami fading.Materials and methods. The effect of operating frequency and ionospheric diffusivity on fading distribution parameters in a single-beam SWRC was estimated by simulating transionospheric communication channels based on a radio-physical phase screen method. The effect of Rician fading parameters on communication reliability was simulated in the MatLab environment. The initial data on ionospheric parameters were obtained using the IRI-2016 model.Results. A three-stage methodology for estimating communication reliability in a single-beam SWRC with Rician fading was developed; its results were compared with that under Nakagami fading. Dependencies were obtained to describe communication reliability in a single-beam SWRC during the day and at night on the selected operating frequency relative to the maximum applicable frequency and on the level of ionospheric diffusivity during Rician and Nakagami fading.Conclusion. The conducted analysis showed that, at different levels of ionospheric diffusivity, communication reliability in a single-beam SWRC with Nakagami fading can be significantly overestimated (up to 12 %), compared to that under Rician fading.

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21

Samosir, Pebri Yeni, Nyoman Pramaita, I. Gst A. Komang Diafari Djuni Hartawan, and Ni Made Ary Esta Dewi Wirastuti. "Performance Analysis of MIMO STBC System in Flat Fading and Frequency Selective Fading Channels." Journal of Electrical, Electronics and Informatics 3, no. 1 (2019): 19. http://dx.doi.org/10.24843/jeei.2019.v03.i01.p04.

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Multiple Input Multiple Output (MIMO) technology is a technique that can be used to overcome multipath fading. The multipath fading is caused by signals coming from several paths that experience different attenuations, delays and phases. In a multipath condition, an impulse that sent by the transmitter, will be received by the recipient not as an impulse but as a pulse with a spread width that called delay spread. Delay spread can cause intersymbol interference (ISI) and bit translation errors from the information received. To determine the effect of delay spread on the MIMO system, then MIMO system performance research was performed on flat fading and frequency selective fading channels using the Space Time Block Code (STBC) coding technique. This research was conducted using MatLab 2018a software. The simulation results show that the MIMO STBC system performance on flat fading channels is better than the MIMO STBC system performance on the frequency selective fading channel. This result is analyzed based on the value of BER vs. Eb/No and eye diagram.

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22

Tran, Le-Nam, Een-Kee Hong, and Huaping Liu. "A frequency domain equalization algorithm for fast time-varying fading channels." Journal of Communications and Networks 11, no. 5 (2009): 474–80. http://dx.doi.org/10.1109/jcn.2009.6388391.

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23

Wing Seng Leon and D. P. Taylor. "An adaptive receiver for the time- and frequency-selective fading channel." IEEE Transactions on Communications 45, no. 12 (1997): 1548–55. http://dx.doi.org/10.1109/26.650233.

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24

Zhiqiang Liu and G. B. Giannakis. "Space-time block-coded multiple access through frequency-selective fading channels." IEEE Transactions on Communications 49, no. 6 (2001): 1033–44. http://dx.doi.org/10.1109/26.930633.

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25

Rhee, D., H. G. Hwang, Y. J. Sang, and K. S. Kim. "Multiuser adaptive transmission technique for time-varying frequency-selective fading channels." Signal Processing 88, no. 8 (2008): 2095–107. http://dx.doi.org/10.1016/j.sigpro.2008.02.014.

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26

Li, Yong-zhao, Gui-sheng Liao, and Wen-ning Tong. "Space-time coded eigenbeamforming for downlink frequency-selective correlated fading channels." Journal of Shanghai University (English Edition) 10, no. 6 (2006): 500–505. http://dx.doi.org/10.1007/s11741-006-0046-1.

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27

Al-Rawi, Muhanned. "Study of Code Acquisition of FHSS System Over Rician Channel." Land Forces Academy Review 24, no. 1 (2019): 68–76. http://dx.doi.org/10.2478/raft-2019-0008.

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Abstract Frequency hopping is used in different communications systems for its robustness by providing frequency diversity against jamming and interfering signals. Successful detection and demodulation of a frequency hopping signal is dependent on proper tuning to transmit frequency and time synchronization of the burst. The sequence of hop frequencies is generally determined by a Pseudo-Noise (PN) sequence and time synchronization is achieved using synchronization preambles in the transmit burst. Successful acquisition of the hop frequency sequence could be achieved when at least a single burst’s data is successfully decoded at the receiver. This paper studies the serial search code acquisition which is the first step of synchronization for frequency hopping spread spectrum (FHSS) system over Rician fading channel. Simulation results show the effect of fading channel on the code acquisition.

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28

Zheng, Jing, and Zulin Wang. "ICI Analysis for FRFT-OFDM Systems to Frequency Offset in Time-Frequency Selective Fading Channels." IEEE Communications Letters 14, no. 10 (2010): 888–90. http://dx.doi.org/10.1109/lcomm.2010.072910.100562.

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29

Tami, Abdelkader, Mokhtar Keche, and Boubaker S. Bouazza. "New OSTBC for Blind Channel Estimation and Tracking in MIMO-OFDM Systems." Journal of Telecommunications and Information Technology 3 (September 30, 2019): 49–57. http://dx.doi.org/10.26636/jtit.2019.133819.

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Applying orthogonal space time block coding (OSTBC) to multiple-input multiple-output (MIMO) systems helps reduce receiver complexity. However, this approach has been applied only to ﬂat fading channels, as when the channel is a frequency selective fading MIMO channel, OSTBC cannot be used directly since its orthogonal propriety may be lost. Furthermore, the MIMO channel is not always known. To deal with this problem, many techniques were proposed to estimate the channel using a training sequence. Unfortunately, these techniques reduce the useful spectral bandwidth. This paper proposes OSTBC for blind channel estimation and data detection in the case of a MIMO frequency selective channel. The aim of this new OSTBC is twofold: to solve the ambiguity of channel estimation and to reduce the complexity of the detector. By exploiting the well-known technique of orthogonal frequency division multiplexing (OFDM), the frequency selective fading MIMO channel is split into a set of ﬂat fading subchannels. Moreover, to accommodate the fact that a MIMO channel can be time varying, the steady state Kalman channel estimator (SS-KCE) is extended to track the channel’s fast variations. The performance of the proposed blind algorithm is related by the adequate choice of the number of subcarriers and it is compared with other existing approaches by means of Monte Carlo simulations.

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30

Al-Qadi, Osama, Bertus Tazifua, and Evgeniy Semenov. "Analysis of Discrete Message Transmission in Orthogonal Frequency Division Multiplexing Systems." NBI Technologies, no. 4 (2022): 5–9. http://dx.doi.org/10.15688/nbit.jvolsu.2022.4.1.

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High data transfer rates are required in modern digital radio transmission systems. But an increase in the data transfer rate leads to a deterioration in the transmission quality and a high BER (bit error rate). OFDM technology, which was introduced in the 1960s, implements all these functions. In this paper, the influence of fading channels on the transmission of information in OFDM systems is investigated. In wireless systems for transmitting discrete messages, the channel parameters greatly affect the transmission quality, as interference, noise and fading affect the useful signal. Fading is a very common phenomenon in wireless communication systems, affecting the phase shift of the signal. In an urban environment, multipath propagation of signals also takes place, since signals propagate along two or more paths before reaching the receiver. Depending on the signal propagation medium and communication conditions, small-scale fading can be distinguished. At the same time, there are significant changes in the amplitude and phase of the signal. Small-scale fading occurs on a smaller scale, comparable to the wavelength of the transmitted signal, and often changes throughout the signal path, and may change one or more times during the transmission time of the symbol, which leads to so-called flat (smooth) and frequency-selective fading. The results obtained show the effect of fading on the digital transmission system (OFDM). The three discrete message delay profiles used represent a low-, medium-, and high-latency propagation environment, respectively. A model of a wireless digital communication system (OFDM) has been built using the SystemVue software.

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31

Pan, P., L. L. Yang, and Y. Zhang. "Time-frequency iterative multiuser detection in time-frequency-domain spread multicarrier DS-CDMA systems over Nakagami-m fading channels." European Transactions on Telecommunications 22, no. 1 (2010): 2–13. http://dx.doi.org/10.1002/ett.1439.

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32

Shengli Zhou and G. B. Giannakis. "Single-carrier space-time block-coded transmissions over frequency-selective fading channels." IEEE Transactions on Information Theory 49, no. 1 (2003): 164–79. http://dx.doi.org/10.1109/tit.2002.806158.

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33

Jang, J., K. B. Lee, and Y. H. Lee. "Frequency-time domain transmit power adaptation for multicarrier system in fading channels." Electronics Letters 38, no. 5 (2002): 218. http://dx.doi.org/10.1049/el:20020166.

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34

Yeh, Hen-Geul, and Samet Yildiz. "Space–Time Trellis-Coded OFDM Systems in Frequency-Selective Mobile Fading Channels." IEEE Transactions on Circuits and Systems II: Express Briefs 64, no. 6 (2017): 660–64. http://dx.doi.org/10.1109/tcsii.2016.2598083.

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35

Cheng, C. C., and C. C. Lu. "Space–Time Code Design for CPFSK Modulation Over Frequency-Nonselective Fading Channels." IEEE Transactions on Communications 53, no. 9 (2005): 1477–89. http://dx.doi.org/10.1109/tcomm.2005.855006.

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36

LIU, HUAPING, VINOD VENKATESAN, MARIO E. MAGAÑA, CURT NILSEN, and RON KYKER. "PERFORMANCE OF FREQUENCY HOPPED NONCOHERENT GFSK OVER TIME-VARYING RAYLEIGH FADING CHANNELS." International Journal on Wireless & Optical Communications 02, no. 01 (2004): 51–61. http://dx.doi.org/10.1142/s0219799504000209.

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37

Yong Li and Jaekyun Moon. "Bit-interleaved space-time trellis coding for frequency selective block fading channels." IEEE Communications Letters 10, no. 1 (2006): 40–42. http://dx.doi.org/10.1109/lcomm.2006.1576563.

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38

LEE, H. "Iterative Sequential OFDM Symbol Estimation Algorithm over Time-Frequency-Selective Fading Channels." IEICE Transactions on Communications E89-B, no. 6 (2006): 1922–25. http://dx.doi.org/10.1093/ietcom/e89-b.6.1922.

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39

He, Jianqiang, Guoxiang Gu, and Zhongshan Wu. "MMSE Interference Suppression in MIMO Frequency Selective and Time-Varying Fading Channels." IEEE Transactions on Signal Processing 56, no. 8 (2008): 3638–51. http://dx.doi.org/10.1109/tsp.2008.919389.

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40

Borah, D. K., and B. D. Hart. "A robust receiver structure for time-varying, frequency-flat, Rayleigh fading channels." IEEE Transactions on Communications 47, no. 3 (1999): 360–64. http://dx.doi.org/10.1109/26.752815.

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41

Borah, D. K., and B. T. Hart. "Frequency-selective fading channel estimation with a polynomial time-varying channel model." IEEE Transactions on Communications 47, no. 6 (1999): 862–73. http://dx.doi.org/10.1109/26.771343.

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42

Qiu, Wenxun, Hlaing Minn, and Chia-Chin Chong. "An Efficient Diversity Exploitation in Multiuser Time-Varying Frequency-Selective Fading Channels." IEEE Transactions on Communications 59, no. 8 (2011): 2172–84. http://dx.doi.org/10.1109/tcomm.2011.060911.090439.

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43

Long, Yi, Linling Kuang, and Jianhua Lu. "Precoded OFDM system for ICI mitigation over time-frequency selective fading channels." Tsinghua Science and Technology 14, no. 2 (2009): 206–11. http://dx.doi.org/10.1016/s1007-0214(09)70031-8.

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44

Zhou, S., and G. B. Giannakis. "Space-time coding with maximum diversity gains over frequency-selective fading channels." IEEE Signal Processing Letters 8, no. 10 (2001): 269–72. http://dx.doi.org/10.1109/97.957268.

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45

Zhu, Jiangzhang, Shuangchun Wen, and Qingsong Du. "Space-frequency-Doppler coded OFDM over the time-varying Doppler fading channels." AEU - International Journal of Electronics and Communications 62, no. 4 (2008): 307–15. http://dx.doi.org/10.1016/j.aeue.2007.04.004.

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46

Stoica, Petre, and Girish Ganesan. "Trained Space-Time Block Decoding for Flat Fading Channels with Frequency Offsets." Wireless Personal Communications 27, no. 3 (2003): 235–45. http://dx.doi.org/10.1023/b:wire.0000010147.39594.2a.

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47

Kai-Kit Wong, R. D. Murch, and K. B. Letaief. "Optimizing time and space MIMO antenna system for frequency selective fading channels." IEEE Journal on Selected Areas in Communications 19, no. 7 (2001): 1395–407. http://dx.doi.org/10.1109/49.932706.

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48

Hatanaka, Masahide, Toru Homemoto, and Takao Onoye. "Architecture and Implementation of Fading Compensation for Dynamic Spectrum Access Wireless Communication Systems." VLSI Design 2013 (June 6, 2013): 1–9. http://dx.doi.org/10.1155/2013/967370.

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Resumen

This paper proposes an efficient architecture and implementation of fading compensation dedicated to dynamic spectrum access (DSA) wireless communication. Since pilot subcarrier arrangements are adaptively determined in wireless communication systems with DSA, the proposed architecture employs piecewise linear interpolation to the channel response estimation for data subcarriers in order to increase the channel estimation accuracy. The fading compensation for an orthogonal frequency-division multiplexing (OFDM) symbol is performed within the time for one OFDM symbol to make increase of latency smaller. The proposed architecture guarantees real-time processing with 76 MHz or higher clock frequency. The FPGA implementation of the proposed architecture occupies 1,577 slices and works up to 121 MHz.

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49

Teichmann, R., and L. Spillmann. "Fading of Textured Targets on Textured Background." Perception 26, no. 1_suppl (1997): 5. http://dx.doi.org/10.1068/v970094.

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In 1804 Troxler reported that with strict fixation, a small, low-contrast target presented to the peripheral visual field will tend to fade and ultimately become invisible. Further studies have shown that, in addition to stationary targets, moving and flickering targets will also fade. We studied the role of a texture difference between the target and its background on fading. We found that textured targets fade as quickly as, or even faster than, uniform targets. Typically, the target becomes less salient and after a while disappears in the background. Specifically, we asked whether orientation contrast would influence the time of perceptual disappearance. A grating disk of 2 deg diameter and 0.8 cycle deg−1 spatial frequency was presented binocularly on an equally striped background, 15 deg from the fixation point. The orientation of the target relative to that of the background was varied in steps of 15°, yielding eleven stimuli which were presented in a random order. Each orientation was shown a total of nine times. Luminance, spatial frequency, and contrast were the same for both the target and the background. Time to fading was measured for each target orientation. The results show that orientation contrast strongly affects fading. Time to fading was longest when the grating target and the background were oriented at right angles and decreased symmetrically with decreasing orientation contrast. This result supports the hypothesis that fading is an active neuronal process of long-range lateral interactions.

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50

El Gamal, H., A. R. Hammons, Youjian Liu, M. P. Fitz, and O. Y. Takeshita. "On the design of space-time and space-frequency codes for MIMO frequency-selective fading channels." IEEE Transactions on Information Theory 49, no. 9 (2003): 2277–92. http://dx.doi.org/10.1109/tit.2003.815804.

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