Sökning: "Channel state information CSI"

Visar resultat 16 - 20 av 51 avhandlingar innehållade orden Channel state information CSI.

  1. 16. Resource Allocation in Downlink Coordinated Multi-Point Systems

    Författare :Jingya Li; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; backhaul latency; Coordinated multi-point CoMP transmission; imperfect synchronization; fractional frequency reuse; resource allocation; general duality theory; imperfect channel state information; inter-cluster interference coordination;

    Sammanfattning : The raised user expectations of quality of service and the rapid growth of the data traffics impose a great challenge for mobile communication systems. The performance, e.g., the spectrum efficiency, peak data rate, cell-edge data rate, of current cellular systems ismainly limited due to the presence of inter-cell interference. LÄS MER

  3. 17. 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

  4. 18. Massive MIMO Systems with Hardware Imperfections

    Författare :Nikolaos Kolomvakis; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; achievable rate; analogue-to-digital converter; Massive MIMO; channel estimation; in-phase and quadrature imbalance; random matrix theory;

    Sammanfattning : Recent years have witnessed an unprecedented explosion in mobile data traffic, due to the expansion of numerous types of wireless devices. Moreover, each device needs a high throughput to support demanding applications such as real-time video, movie streaming and games. LÄS MER

  5. 19. Design Aspects of Coordinated Multipoint Transmission : A Study of Channel Predictions, Resource Allocation, User Grouping and Robust Linear Precoding for Coherent Joint Transmission

    Författare :Rikke Apelfröjd; Mikael Sternad; Anders Ahlén; Antti Tölli; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Network MIMO; Centralized CoMP; Robust beamforming with imperfect CSI; Limited backhaul; Linear predictions of OFDM channels; Kalman filters; Predictor antennas; Long term channel prediction; Local resource allocation and user grouping; Electrical Engineering with specialization in Signal Processing; Elektroteknik med inriktning mot signalbehandling;

    Sammanfattning : Shadowed areas and interference at cell borders pose great challenges for future wireless broadband systems. Coordinated Multipoint (CoMP) coherent joint transmission has shown the potential to overcome these challenges by turning harmful interference into useful signal power. LÄS MER

  7. 20. A Cross-layered Pilot Scheme for IEEE 802.11p

    Författare :Keerthi Nagalapur; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vehicular communications; FPGA implementation; Channel Estimation; Cross-layer; Pilot Scheme; IEEE 802.11p; OFDM;

    Sammanfattning : Vehicular communication is expected to be a part of the future transportation system and promises to support a plethora of applications for traffic safety, traffic efficiency, and fuel efficiency. Traffic safety applications, such as collision avoidance, demand reliable communications with low latency. LÄS MER