Results 31 to 40 of about 37,114 (119)

Lunar Trailblazer Spacecraft Tracking and Mission Recovery Attempt: Characterization of Status and Behavior of a Non‐Cooperative Object in Cis‐Lunar Space

Earth and Space Science, Volume 13, Issue 8, August 2026.
Abstract Unexpectedly following launch, the Lunar Trailblazer mission experienced software anomalies that led it to orient solar panels away from the sun and lose communication with Earth. This paper describes efforts to determine the spacecraft state and attempt recovery of the mission's science at the Moon.
B. L. Ehlmann, J. Bellerose, G. Lantoine, E. Furlan, E. Scire, S. Fajardo‐Acosta, L. Bennett, M. Sanchez Net, T. J. W. Lazio, M. Brozović, J. Masiero, A. V. Steckel, P. A. Burke, M. Kimura, S. Foxman, M. P. M. Zaw, L. M. Lee, F. Clarke, M. Hauge, D. McDonald, J. Adler, R. Strauss, D. Trilling, C. S. Edwards, M. C. Nolan, D. Lyster, L. Robinson, A. T. Klesh, C. C. Seybold   +28 more
wiley   +1 more source

Cooperative Downlink Multicell Preprocessing Relying on Reduced-Rate Back-Haul Data Exchange [PDF]

, 2011
Different-complexity multicell preprocessing (MCP) schemes employing distributed signal-to-interference leakage-plus-noise ratio (SILNR) precoding techniques are proposed, which require reduced back-haul data exchange in comparison with the conventional ...
Rong Zhang, Zhang, Rong, Hanzo, Lajos, Lajos Hanzo   +3 more
core   +2 more sources

HELIOS ‐ Highly rEliable Links durIng sOlar conjunctionS

Radio Science, Volume 61, Issue 8, August 2026.
Abstract During deep space missions, maintaining reliable communication between a spacecraft and Earth becomes particularly challenging during superior solar conjunctions, when the spacecraft passes behind the Sun relative to Earth. The highly ionized solar corona and solar wind create plasma inhomogeneities that severely affect radio signals, leading ...
A. Zeqaj, P. Tortora, E. Paolini, A. J. Stocker, D. R. Siddle, A. Argyriou, J. De Vicente, R. Abello, M. Mercolino   +8 more
wiley   +1 more source

Orbital Decay of the Three SNIPE CubeSats During the Super Geomagnetic Storm in May 2024

Space Weather, Volume 24, Issue 8, August 2026.
Abstract The Mother's Day (Gannon) geomagnetic superstorm of May 2024 produced extreme thermospheric heating and expansion, resulting in enhanced atmospheric drag on low Earth orbiting (LEO) satellites. We investigate storm‐time thermospheric drag and density variability using three satellites of the Small‐scale magNetospheric and Ionospheric Plasma ...
Hosub Song, Ki‐Hwan Keum, Jaeheung Park, Tae‐Yong Yang, Jongdae Sohn, Youngbum Song, Yihua Zheng, Dae‐Hee Lee, Jaejin Lee   +8 more
wiley   +1 more source

Spatial de-correlation of the UTRA-FDD radio channel [PDF]

, 2000
For smart antenna deployment in Frequency Division Duplex (FDD) applications the downlink weight vector can be derived from the uplink steering vector, assuming a degree of correlation between these channels.
Allen, B, Beach, MA, Karlsson, Peter
core  

Iterative Near-Maximum-Likelihood Detection in Rank-Deficient Downlink SDMA Systems

, 2008
—In this paper, a precoded and iteratively detected downlink multiuser system is proposed, which is capable of operating in rankdeficient scenarios, when the number of transmitters exceeds the number of receivers.
Wei, C.Y., Ng, S.X., Akhtman, J., Hanzo, L.   +3 more
core   +1 more source

Code orthogonality for wideband CDMA systems with multiple transmit antennas [PDF]

, 2007
Code orthogonality is a useful indicator in determining the performance of the synchronous downlink of third generation Universal Mobile Telecommunication System (UMTS) Terrestrial Radio Access systems.
Beach, Mark, Mark A. Beach, Allen, Ben, Hunukumbure, Mythri, Allen, BH, Hunukumbure, MR, Mythri Hunukumbure, Beach, MA, Ben Allen   +8 more
core   +1 more source

Initial and Post-Initial Code Acquisition in the Non-Coherent Multiple Input/Multiple Output Aided DS-CDMA Downlink [PDF]

, 2008
In this paper, we investigate the issues of both initial and post-initial acquisition schemes in the multiple-input/multiple-output (MIMO)-aided direct-sequence code-division multiple-access (DS-CDMA) downlink when communicating over spatially ...
Won, Seung, Won, SeungHwan, Hanzo, Lajos
core   +1 more source

Singular value decomposition-based multiuser multiple-input multiple-output vector perturbation-aided downlink transmitter and lattice-reduction-assisted uplink receiver pair [PDF]

, 2012
: A full-duplex uplink/downlink (UL/DL) system having a UL transmitter/receiver (transceiver) pair and a DL transceiver is considered. Both the UL and DL are improved.
Li, J.-D., Liu, Wei, Li, C, Hanzo, Lajos
core   +1 more source

Modulation-mode assignment for SVD-assisted and iteratively detected downlink multiuser MIMO transmission schemes [PDF]

, 2011
In this contribution we jointly optimize the number of multiple-input multiple-output (MIMO) layers and the number of bits per symbol within an iteratively-detected multiuser MIMO downlink (DL) transmission scheme under the constraint of a given fixed ...
Ahrens, Andreas, Benavente Peces, César
core