orthogonal frequency division multiplexing for high speed optical transmission
Báo cáo hóa học: " High-Speed Turbo-TCM-Coded Orthogonal Frequency-Division Multiplexing Ultra-Wideband Systems" pptx
Ngày tải lên :
22/06/2014, 22:20
... equalization and orthogonal frequency- division
multiplexing (OFDM) [4].
OFDM is a promising solution for efficiently capturing
multipath energy in highly dispersive UWB channels and de-
livering high data ... much higher spectral efficiency, for example, 1.2 Gbps,
which is 2.5 times higher than the proposed system. We identify several essential requirements to achieve the high rate t ransmission,
for ... the IEEE P802.15 WPAN project is to use a multiband orthogonal frequency- division multiplexing
(OFDM) system and punctured convolutional codes for UWB channels supporting a data rate up to 480...
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Tài liệu Báo cáo khoa học: "A HARDWARE ALGORITHM FOR HIGH SPEED MORPHEME EXTRACTION AND ITS IMPLEMENTATION" pptx
Ngày tải lên :
21/02/2014, 20:20
... algorithm
for high speed morpheme extraction, and also de-
scribes its implementation on a specific machine.
This machine,
MEX.I,
is designed as the first step
313
A HARDWARE ALGORITHM
FOR HIGH ... be-
lieve it is suitable for VLSI implementation. Ac-
tually, its VLSI implementation is in progress. A
high speed morpheme extraction VLSI will im-
prove the performance of such text processing ... Step 2 for Procedure 1 are implemented in
each state for (a), (b), (c), (d), (e),
and
so on.
In state (a) for Fig. 4, the index memory's out-
put expresses the address range for the...
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Báo cáo khoa học: "Randomized Algorithms and NLP: Using Locality Sensitive Hash Function for High Speed Noun Clustering" pdf
Ngày tải lên :
08/03/2014, 04:22
... Association for Computational Linguistics
Randomized Algorithms and NLP: Using Locality Sensitive Hash Function
for High Speed Noun Clustering
Deepak Ravichandran, Patrick Pantel, and Eduard Hovy
Information ... Interestingly, cosine similarity is
widely used in NLP for various applications such as
clustering.
In this paper, we perform high speed similarity
list creation for nouns collected from a huge web
corpus. ... calculated
using the traditional formula as given in equation
1. For this base comparison system we use the one
built by Pantel and Lin (2002). We perform 3 kinds
of evaluation: 1. Performance of Locality...
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Báo cáo hóa học: "Research Article Design of an Omnidirectional Multibeam Transmitter for High-Speed Indoor Wireless Communications" doc
Ngày tải lên :
21/06/2014, 17:20
... of configuration E for light undergo-
ing up to five reflections.
power uniformity of the transmitter has yet to be optimized.
For high performance wireless diffuse links with uniform
power illumination ... M. H. Elmirg hani, “Spot diffusing
technique and angle diversity performance for high speed
indoor di
ffuse infra-red wireless transmission, ” IEE Proceed-
ings: Optoelectronics, vol. 151, no. 1, ... view as
well as the power receiving performance.
A prototype multibeam transmitter suitable for produc-
ing uniform, near hemisphere or 180 degree, high speed,
and long distance infrared radiation...
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Báo cáo hóa học: " Research Article VLSI Implementation of a Fixed-Complexity Soft-Output MIMO Detector for High-Speed Wireless" pptx
Ngày tải lên :
21/06/2014, 17:20
... degrees
of freedom in MIMO channels. Since the multiplexing gain
is only available for high SNR region, spatial multiplexing
is usually used when high SNR is available. STBC/SFBC
[11] assumes ... one is
assumed to target high- end users willing to pay more in
area and power for performance (e.g., laptops). The MMSE
single-mode detector is in favor of low-end users for connec-
tivity with ... to 25 dB. For high- end users,
SM is preferred when SNR is at least higher than 10 dB. On
the other hand, the MMSE mode will consume substantiately
lower power than the MFSCO mode, the high- end...
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Báo cáo hóa học: " Research Article Nonlinear Frequency Scaling Algorithm for High Squint Spotlight SAR Data Processing" pdf
Ngày tải lên :
21/06/2014, 22:20
... the range-cell migration with a high- order range-
azimuth coupling form is processed by a nonlinear frequency scaling operation, which is different from the original frequency
scaling one. Due to ... nonlinear frequency scaling method is
presented. Inspired by the NCS algorithm, the FS operation
has been extended to the cubic order to perform a more accu-
rate SRC. Before the nonlinear frequency ... f
ref
= 0 before the
frequency scaling operation will simplify the expressions of
H
FS
, H
MF
,andH
AF
.
3. SIMULATION RESULTS
In order to evaluate the proposed algorithm, some simula-
tions for an...
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Báo cáo hóa học: " Submonolayer Quantum Dots for High Speed Surface Emitting Lasers" potx
Ngày tải lên :
22/06/2014, 18:20
... signal modulation
experiments have been performed at lower temperatures,
but the high speed performance at 85 °C is crucial for most
short-distance optical interconnect applications.
Thus, we ... simultaneously to a significant lateral
compositional modulation and high QD density [34],
resulting in a high material and modal gain.
For ultrahigh -speed directly modulated VCSEL appli-
cations it is extremely ... excellent static performance, i.e. high
external efficiency even at 85 °C, these devices demon-
strate the potential of this novel active material for
temperature stable ultra high speed VCSELs. At...
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Báo cáo hóa học: " Research Article Towards Scalable MAC Design for High-Speed Wireless LANs" ppt
Ngày tải lên :
22/06/2014, 19:20
... channel conditions, TMAC pro-
vides more transmission opportunities for high- rate stations
perceiving good channels. This feature is important for high-
speed wireless LANs and mesh networks to ... to high- speed wireless networks. The MAC de-
sign in high- speed wireless networks, such as IEEE 802.11n,
8 EURASIP Journal on Wireless Communications and Networking
Table 3: Analysis results for ... stations,
high- rate and low-rate stations, by defining the reference pa-
rameters, namely, the reference transmission rate R
f
and the
reference time duration T
f
. Stations with transmission rates
higher...
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hsdpahsupa for umts high speed radio access for mobile communications
Ngày tải lên :
01/06/2014, 09:38
... High- Speed Dedicated Physical Control CHannel
HS-DSCH High- Speed Downlink Shared CHannel
HS-PDSCH High- Speed Physical Downlink Shared CHannel
HS-SCCH High- Speed Shared Control CHannel
HSDPA High- Speed ... Control CHannel
HSDPA High- Speed Downlink Packet Access
HSPA High- Speed Packet Access
HSUPA High- Speed Uplink Packet Access
Abbreviations xvii
Higher cell capacity and higher spectral efficiency ... radio access has evolved strongly alongside high- speed downlink packet
access (HSDPA) and high- speed uplink packet access (HSUPA), together called high-
speed packet access’ (HSPA). When the International...
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Báo cáo hóa học: " Research Article Pulse Interval Modulation for Ultra-High Speed IR-UWB Communications Systems" pdf
Ngày tải lên :
21/06/2014, 08:20
... multiple access (CDMA)
scheme based on strict optical orthogonal codes (SOOC) i s proposed. This scheme is suitable for multiuser high- speed data
asynchronous transmission applications because the average ... interval modulation for optical
communications,” IEEE Communications Magazine, vol. 36,
no. 12, pp. 95–99, 1998.
[13] T. Svedek and S. Rupcic, “Anisochronous modulation methods
for optical short-range ... Broadcasting (PGNET
’00), pp. 195–200, June 2000.
[15] J G. Zhang, “Strict optical orthogonal codes for purely asyn-
chronous code -division multiple-access applications,” Applied
Optics, vol. 35, no....
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Báo cáo hóa học: " Research Article Novel Techniques of Single-Carrier Frequency-Domain Equalization for Optical Wireless Communications" doc
Ngày tải lên :
21/06/2014, 08:20
... receivers for optical signals. These
opto electronic devices are cheaper as compared to RF
equipments.
Orthogonal frequency division multiplexing (OFDM)
modulation is a promising modulation scheme for ... OFDM systems for DOW
transmission, the asymmetrically clipped optical orthogonal
frequency division multiplexing (ACO-OFDM) [7]hasbeen
shown to be more efficient in terms of optical power than
the ... investigate the use of single carrier frequency domain equalization (SCFDE) over a diffuse optical wireless (DOW)
communications. Recently orthogonal frequency division multiplexing (OFDM) has been applied...
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Báo cáo sinh học: " Research Article Time-Frequency Based Channel Estimation for High-Mobility OFDM Systems—Part II: Cooperative Relaying Case" pptx
Ngày tải lên :
21/06/2014, 16:20
... performance
for
−40 and 40 dB and obtain better results for
G
SR
/G
RD
= 0dB as in the individual channel
estimation case. We show the BER performance for
G
SR
/G
RD
={−40, 0,40}dB,aswellasfortheperfect
CSI ... Transactions on Information Theory, vol. 50,
no. 12, pp. 3062–3080, 2004.
[4] H. Do
ˇ
gan, “Maximum a posteriori channel estimation for
cooperative diversity orthogonal frequency- division multi-
plexing ... estimation performance in both
approaches. We show the BER and MSE plots in Figures
4(a) and 4(b),respectively,forP
={8, 16,32}.Notice
that increasing the number of pilots improves the BER
performance...
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Báo cáo hóa học: " Research Article Practical Quantize-and-Forward Schemes for the Frequency Division Relay Channel" potx
Ngày tải lên :
22/06/2014, 00:20
... assertion can be proven for the two combiners pro-
vided in this paper, for more information see [12]). There-
fore, one has to keep in mind that in quasistatic channels
the performance gain due to ... quasistatic
orthogonal relay channels for which orthogonality is defined
accordingly to [1]. Since the source-destination channel is
assumed to be orthogonal to the relay-destination channel
(i.e., the forward ... QF versus uniform QF
All the simulations we performed showed one significant
drawback of the uniform QF relaying protocol. Both in static
and quasistatic channels, the receiver performance, when...
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Báo cáo hóa học: " Research Article Development of Long-Range and High-Speed Wireless LAN for the Transmission of Telemedicine from Disaster Areas" pdf
Ngày tải lên :
22/06/2014, 06:20
... respectively. SIF stands for source input
format. HalfD1 stands for video size of 352
ì 480 pixels for
one frame. FullD1 stands for 720
ì 480 pixels for one frame.
Masayuki Nakamura et al. 5
Japan
Nagano
Prefecture
To ... found
to have very high video quality at high compression rates.
Taking this result into account, we decided to use (4)-(c)
compression format in this drill.
As a result, transmission rates between ... compression format of (4)-(f) is used.
Therefore, there is almost no delay in video and sound trans-
mission.
3.3. A portable live video transmission system
Figure 11 shows the portable live video transmission...
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Báo cáo hóa học: " Joint Downlink Power Control and Multicode Receivers for Downlink Transmissions in High Speed UMTS" pot
Ngày tải lên :
22/06/2014, 22:20
... (2002-03), High Speed Downlink
Packet Access: Physical layer aspects, (Release 5)”.
[3] B. Sayadi and I. Fijalkow, “Joint detection for multicode trans-
mission in downlink high speed UMTS,” ... proposed for a multirate and multicode
DS-CDMA system follows the structur al principles of practi-
cal downlink UMTS and leads to a convenient algebraic form
whichallowsforapowerfulreceiverdesignforamulticode
multirate ... MMSE) show
good performance. Adding more virtual users brings the
conv entional receiver to even worse performance as is shown
in Figure 3.
For M
1
= 64, the different lines for each receiver type
correspond...
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