Sökning: "multiple antennas"

Visar resultat 41 - 45 av 150 avhandlingar innehållade orden multiple antennas.

1. 41. Multihop Wireless Networks with Advanced Antenna Systems : An Alternative for Rural Communication

   Författare :Marvin Sánchez Garache; Jens Zander; Martha Steenstrup; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multihop Wirless Networks; Advanced Antenna Systems; Multiple Access Protocols; Spatial TDMA; CSMA CA; link-scheduling; power control; variable transmission rate; Telecommunication; Telekommunikation;

   Sammanfattning : Providing access to telecommunication services in rural areas is of paramount importance for the development of any country. Since the cost is the main inhibiting factor, any technical solution for access in sparsely populated rural areas has to be reliable, efficient, and deployable at low-cost. LÄS MER

3. 42. Channel Estimation and Receiver Design in Single- and Multiuser Multiantenna Systems : Dissertation Submitted for the Degree of Doctor of the Hungarian Academy of Sciences

   Författare :Gabor Fodor; Ericsson Research; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multiple antenna systems; estimation theory; stochastic modeling; Electrical Engineering; Elektro- och systemteknik; Telecommunication; Telekommunikation;

   Sammanfattning : As an engineer and researcher, I have been dealing with the research, standardization and industrial-ization of wireless communication systems since the late 90’s. Specifically, I have been witnessing andcontributing to the evolution of the 3rd, 4th and currently to the 5th generation of cellular networks. LÄS MER

4. 43. Characterization of Terminal Antennas for Diversity and MIMO Systems by Theory, Simulations and Measurements in Reverberation Chamber

   Författare :Kent Rosengren; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mode stirred chamber; embedded pattern; channel capacity; radiation efficiency; reverberation chamber; embedded element; MIMO; diversity gain;

   Sammanfattning : This thesis is based on the work of designing and building a small reverberation chamber, and to use this chamber for characterization of antennas on mobile terminals such as phones. The characterization is done in terms of radiation efficiency, diversity gain and maximum available capacity. LÄS MER

5. 44. Characterization of Small Antennas & Wireless Devices for MIMO Systems in Rich Isotropic Multipath & Random Line-of-Sight

   Författare :Ahmed Hussain; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MIMO; Rayleigh; reverberation chamber; random LOS; RIMP; LTE; OTA;

   Sammanfattning : The current thesis is about over-the-air (OTA) performance characterization of wireless terminals in rich isotropic multipath (RIMP) environment as well as in pure line-of-sight (LOS) environment while not ignoring the random positions and orientations of the mobile terminals due to randomness of the user. The latest mobile wireless terminals such as iPhone and iPad can be used in any random position and orientation thereby making the received LOS-component toappear as a random voltage at the antenna ports. LÄS MER

7. 45. Massive Multi-Antenna Communications with Low-Resolution Data Converters

   Författare :Sven Jacobsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; orthogonal frequency-division multiplexing; channel estimation; quantization; linear precoding; convex optimization; nonlinear precoding; linear combing; hardware impairments; analog-to-digital converter; beamforming; Massive multi-user multiple-input multiple-output; digital-to-analog converter;

   Sammanfattning : Massive multi-user (MU) multiple-input multiple-output (MIMO) will be a core technology in future cellular communication systems. In massive MU-MIMO systems, the number of antennas at the base station (BS) is scaled up by several orders of magnitude compared to traditional multi-antenna systems with the goals of enabling large gains in capacity and energy efficiency. LÄS MER