An Efficient Pilot Scheme in Large-Scale Two-Way Relay Systems

We propose a novel time-shift pilot scheme to mitigate the pilot contamination in large-scale multicell multiuser MIMO (LS-MIMO) systems. In the proposed scheme, the length of the uplink training pilot sequence is equal to the cell number; that is to say, the same pilot sequence is used within a cell, while for different cells, pilot sequences are mutually orthogonal. Moreover, users within a cell transmit the same pilot sequence in a time-shift manner during the channel estimation stage and in this way all user terminals’ channel state information can be estimated without contamination. The asymptotic channel orthogonality is studied in the LS-MIMO system, with which the mutual interference among cells caused by data and pilot sequences can be cancelled with the successive interference cancellation (SIC) method. We explore the superiority of the proposed scheme in channel coefficient estimation, uplink data detection, and downlink data transmission steps. Theoretical analysis and simulation results demonstrate that the proposed time-shift pilot design can alleviate the pilot contamination problem and improve the performance of the considered system significantly compared with the popular orthogonal pilots.

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The Effects of Reducing Tracking in Upper Secondary School: Evidence from a Large-Scale Pilot Scheme

The Journal of Human Resources ◽

10.1353/jhr.2012.0003 ◽

2012 ◽

Vol 47 (1) ◽

pp. 237-269 ◽

Cited By ~ 32

Author(s):

Caroline Hall

Keyword(s):

Secondary School ◽

Large Scale ◽

Upper Secondary School ◽

Pilot Scheme ◽

Upper Secondary

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Complexity-Aware Relay Selection for 5G Large-Scale Secure Two-Way Relay Systems

IEEE Transactions on Vehicular Technology ◽

10.1109/tvt.2016.2621126 ◽

2017 ◽

Vol 66 (6) ◽

pp. 5461-5465 ◽

Cited By ~ 25

Author(s):

Chensi Zhang ◽

Jianhua Ge ◽

Jing Li ◽

Fengkui Gong ◽

Haiyang Ding

Keyword(s):

Relay Selection ◽

Large Scale ◽

Relay Systems ◽

Selection For

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Channel Estimation for Full-Duplex Relay Systems With Large-Scale Antenna Arrays

IEEE Transactions on Wireless Communications ◽

10.1109/twc.2016.2593729 ◽

2016 ◽

Vol 15 (10) ◽

pp. 6925-6938 ◽

Cited By ~ 17

Author(s):

Xin Xiong ◽

Xiaodong Wang ◽

Taneli Riihonen ◽

Xiaohu You

Keyword(s):

Channel Estimation ◽

Antenna Arrays ◽

Large Scale ◽

Full Duplex ◽

Relay Systems ◽

Full Duplex Relay

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Identifying extreme hottest days from large scale upper air data: a pilot scheme to find California Central Valley summertime maximum surface temperatures

Climate Dynamics ◽

10.1007/s00382-011-0999-z ◽

2011 ◽

Vol 37 (3-4) ◽

pp. 587-604 ◽

Cited By ~ 19

Author(s):

Richard Grotjahn

Keyword(s):

Large Scale ◽

Central Valley ◽

Maximum Surface ◽

Pilot Scheme ◽

Surface Temperatures

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Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

International Astronomical Union Colloquium ◽

10.1017/s0252921100031493 ◽

1999 ◽

Vol 173 ◽

pp. 243-248

Author(s):

D. Kubáček ◽

A. Galád ◽

A. Pravda

Keyword(s):

Image Processing ◽

Large Scale ◽

Harvard College ◽

Oak Ridge ◽

Large Scale Structures ◽

Short Period Comet ◽

Short Period ◽

Scale Structures ◽

Harvard College Observatory ◽

Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

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Evolution of Large-Scale Coronal Structures

International Astronomical Union Colloquium ◽

10.1017/s0252921100024945 ◽

1994 ◽

Vol 144 ◽

pp. 29-33

Author(s):

P. Ambrož

Keyword(s):

Magnetic Field ◽

Field Line ◽

Large Scale ◽

Coronal Magnetic Field ◽

Source Surface ◽

Solar Cycles ◽

Characteristic Relationship ◽

The Magnetic Field ◽

Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

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