Sökning: "Channel feedback"
Visar resultat 21 - 25 av 103 avhandlingar innehållade orden Channel feedback.
21. Design Aspects of Coordinated Multipoint Transmission : A Study of Channel Predictions, Resource Allocation, User Grouping and Robust Linear Precoding for Coherent Joint Transmission
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
22. On Receiver Algorithms for OFDM Systems
Sammanfattning : This thesis addresses the problem of designing a receiver for an Orthogonal FrequencyDivisionMultiplexing (OFDM)communication system operating over fading channels, taking into account the effects of hardware imperfections. We discuss solutions for efficiently estimating the parameters of a channel model and for compensating oscillator phase noise and analog to digital converter (ADC) quantisation errors at the receiver. LÄS MER
23. Short-Packet Communications: Fundamental Performance and Key Enablers
Sammanfattning : The paradigm shift from 4G to 5G communications, predicted to enable new use cases such as ultra-reliable low-latency communications (URLLC), will enforce a radical change in the design of communication systems. Unlike in 4G systems, where the main objective is to have a large transmission rate, in URLLC, as implied by its name, the objective is to enable transmissions with low latency and, simultaneously, very high reliability. LÄS MER
24. Multirate Codes and Multicarrier Modulation for Future Communication Systems
Sammanfattning : In this thesis, new detection and modulation methods for multicarrier systems are presented. The proposed multicarrier detectors are based on feedback of previously detected symbols and the idea is to exploit the correlation, both in time between consecutive symbols, and in frequency between neighboring sub-carriers. LÄS MER
25. Resource Allocation in Multi-Antenna Communication Systems with Limited Feedback
Sammanfattning : The use of multiple transmit antennas is considered a key ingredient to significantly improve the spectral efficiency of wireless communication systems beyond that of currently employed systems. Transmit beamforming schemes have been proposed to exploit the spatial characteristics of multi-antenna radio channels; that is, multiple-input single-output (MISO) channels. LÄS MER