Sökning: "user selection"

Visar resultat 1 - 5 av 143 avhandlingar innehållade orden user selection.

1. 1. Improving User Experience of Internet Services in Cellular Networks

   Författare :Annika Klockar; Brunström Anna; Patrik Arlos; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Internet; cellular networks; wireless; TCP; ARQ; handover; queuing; CoMP; application utility; user selection; scheduling; fairness; Datavetenskap; Computer Science;

   Sammanfattning : The Internet has grown enormously since the introduction of the World Wide Web in the early 90's. The evolution and wide spread deployment of cellular networks have contributed to make the Internet accessible to more people in more places. The cellular networks of today offer data rates high enough for most Internet services. LÄS MER

3. 2. Transceiver Design for Multiple Antenna Communication Systems with Imperfect Channel State Information

   Författare :Xi Zhang; Björn Ottersten; Miguel Lagunas; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MIMO; imperfect CSI; linear transceiver; beamforming; user selection; robust design; channel statistics; Telecommunication; Telekommunikation;

   Sammanfattning : Wireless communication links with multiple antennas at both the transmitter and the receiver sides, so-called multiple-input-multiple-output (MIMO)systems, are attracting much interest since they can significantly increase the capacity of band-limited wireless channels to meet the requirements of the future high data rate wireless communications. The treatment of channel state information (CSI) is critical in the design of MIMO systems. LÄS MER

4. 3. Access selection in multi-system architectures : cooperative and competitive contexts

   Författare :Johan Hultell; Jens Andersson; Heikki Hämmäinen; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Telecommunication; Telekommunikation;

   Sammanfattning : Future wireless networks will be composed of multiple radio access technologies (RATs). To benefit from these, users must utilize the appropriate RAT, and access points (APs). In this thesis we evaluate the efficiency of selection criteria that, in addition to path-loss and system bandwidth, also consider load. LÄS MER

5. 4. Subject retrieval in web-based library catalogs

   Författare :Koraljka Golub; Jadranka Lasić-Lazić; Department of Information Science Filozofski fakultet u Zagrebu; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; British university libraries; Croatian university libraries; Indexing and retrieval systems; Online library catalogs; Subject access points; Subject retrieval; User interface; User search behavior; WebPACs; Library and Information Science; Biblioteks- och informationsvetenskap;

   Sammanfattning : This thesis has been motivated by past research, problems and realizations that online library catalog users frequently perform subject searches – using keywords, subject headings and descriptors – and these searches have yielded unsatisfactory results. Web-based catalogs or WebPACs (Web-based Online Public Access Catalogs), belonging to the so-called third generation of online catalogs and providing a wide variety of search options, remain largely underutilized despite the continuous advancement of information retrieval systems. LÄS MER

7. 5. Doctoral Thesis: Massive MIMO in Real Propagation Environments

   Författare :Xiang Gao; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Massive MIMO; very-large MIMO; multi-user MIMO; channel measurements; channel modeling; 5G; sum-rate capacity; antenna selection; signal processing;

   Sammanfattning : Mobile communications are now evolving towards the fifth generation (5G). In the near future, we expect an explosive increase in the number of connected devices, such as phones, tablets, sensors, connected vehicles and so on. Much higher data rates than in today's 4G systems are required. LÄS MER