Results 11 to 20 of about 13,719,025 (270)
Near-Field Communications: A Tutorial Review [PDF]
IEEE Open Journal of the Communications Society, 2023 Extremely large-scale antenna arrays, tremendously high frequencies, and new types of antennas are three clear trends in multi-antenna technology for supporting the sixth-generation (6G) networks.
Yuanwei Liu +5 more
semanticscholar +1 more source
Channel Estimation for Extremely Large-Scale MIMO: Far-Field or Near-Field? [PDF]
IEEE Transactions on Communications, 2021 Extremely large-scale multiple-input-multiple-output (XL-MIMO) is promising to meet the high rate requirements for future 6G. To realize efficient precoding, accurate channel state information is essential. Existing channel estimation algorithms with low
Mingyao Cui, Linglong Dai
semanticscholar +1 more source
Multiple Access for Near-Field Communications: SDMA or LDMA? [PDF]
IEEE Journal on Selected Areas in Communications, 2022 Spatial division multiple access (SDMA) is essential to improve the spectrum efficiency for multi-user multiple-input multiple-output (MIMO) communications.
Zidong Wu, Linglong Dai
semanticscholar +1 more source
Beam Focusing for Near-Field Multi-User MIMO Communications [PDF]
IEEE Transactions on Wireless Communications, 2021 Large antenna arrays and high-frequency bands are two key features of future wireless communication systems. The combination of large-scale antennas with high transmission frequencies often results in the communicating devices operating in the near-field
Haiyang Zhang +5 more
semanticscholar +1 more source
A Tutorial on Near-Field XL-MIMO Communications Toward 6G [PDF]
IEEE Communications Surveys and Tutorials, 2023 Extremely large-scale multiple-input multiple-output (XL-MIMO) is a promising technology for the sixth-generation (6G) mobile communication networks. By significantly boosting the antenna number or size to at least an order of magnitude beyond current ...
Haiquan Lu +11 more
semanticscholar +1 more source
6G Wireless Communications: From Far-Field Beam Steering to Near-Field Beam Focusing [PDF]
IEEE Communications Magazine, 2022 6G networks will be required to support higher data rates, improved energy efficiency, lower latency, and more diverse users compared with 5G systems. To meet these requirements, electrically extremely large-scale antenna arrays are envisioned to be key ...
Haiyang Zhang +4 more
semanticscholar +1 more source
Fast Near-Field Beam Training for Extremely Large-Scale Array [PDF]
IEEE Wireless Communications Letters, 2022 In this letter, we study efficient near-field beam training design for the extremely large-scale array (XL-array) communication systems. Compared with the conventional far-field beam training method that searches for the best beam direction only, the ...
Yunpu Zhang, Xun Wu, Changsheng You
semanticscholar +1 more source
Channel Estimation for Extremely Large-Scale Massive MIMO: Far-Field, Near-Field, or Hybrid-Field? [PDF]
IEEE Communications Letters, 2021 Extremely large-scale massive MIMO (XL-MIMO) is a promising technique for future 6G communications. However, existing far-field or near-field channel model mismatches the hybrid-field channel feature in the practical XL-MIMO system.
Xiuhong Wei, Linglong Dai
semanticscholar +1 more source
Evolution of an optical vortex with initial fractional topological charge [PDF]
Компьютерная оптика, 2021 In a number of theoretical (J. Opt. 6, 259 (2004)) and experimental (Opt Express 19, 5760 (2011)) works, an original fractional-TC optical vortex (with TC standing for topological charge) was shown to evolve into an integer optical vortex whose TC is ...
V.V. Kotlyar , A.G. Nalimov
doaj +1 more source
Near-Field Integrated Sensing and Communications [PDF]
IEEE Communications Letters, 2023 A near-field integrated sensing and communications (ISAC) framework is proposed, which introduces an additional distance dimension for both sensing and communications compared to the conventional far-field system.
Zhao-Jie Wang, Xidong Mu, Yuanwei Liu
semanticscholar +1 more source