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Visar resultat 1 - 5 av 15 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Optimization and Learning for Large-Scale MIMO-OFDM Wireless Systems : Theory, Algorithms, and Applications

    Författare :Shashi Kant; Carlo Fischione; Mats Bengtsson; Bo Göransson; Gabor Fodor; Christoph Studer; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; First-Order Optimization; Convex Optimization; ADMM; Three-operator ADMM TOP-ADMM ; EVM; OOBE; PAPR; ACLR; MIMO; OFDM; Federated Learning; Telecommunication; Telekommunikation; Optimeringslära och systemteori; Optimization and Systems Theory; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The requirements for next-generation wireless communications networks, particularly fifth-generation (5G) and beyond, are driven by at least three broad use cases. These include enhanced mobile broadband services to support extremely high data rates in terms of network or per user in both uplink and downlink, massive machine-type communications to accommodate massive internet-of-things applications, and critical machine-type communications to handle mission-critical applications that require ultra-high reliability and low latency. LÄS MER

  3. 2. Nonlinearity in Broadband Wireless Communication Systems

    Författare :Ali Behravan; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; baseband predistortion; single carrier modulation; orthogonal frequency division multiplexing OFDM ; bandpass nonlinearity; multicarrier modulation; nonlinearity distortion; high power amplifier; RF predistortion; peak to average power ratio PAPR ; baseband nonlinearity;

    Sammanfattning : In the implementation of a digital communication system, there often exist imperfections that are not considered in the primary design. One such imperfection is the nonlinearity of the front-end devices. LÄS MER

  4. 3. Robust Transceiver Design and Waveform Synthesis for Wideband MIMO Radar

    Författare :Marie Ström; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wideband radar; Robust analysis; Interference; Waveform synthesis; Transmit–receive filter design; MIMO radar;

    Sammanfattning : This thesis deals with the problem of designing and synthesizing waveforms that are optimal, both in a signal-to-noise-and-interference ratio (SNIR), and in a system hardware design perspective, i.e., to synthesize time domain waveforms with a low peak-to-average power ratio (PAPR), or even constant modulus. LÄS MER

  5. 4. Modulation and channel effects in digital communication

    Författare :Sara Sandberg; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

    Sammanfattning : This thesis investigates three possible methods to increase the performance of digital communication systems, with focus on wireless systems, by accounting for some of the channel effects that may occur. The modulation scheme plays an important role in the impact of different channel effects on system performance and this work considers both a single-carrier system and orthogonal frequency-division multiplexing (OFDM). LÄS MER

  7. 5. Evaluation and Compensation of Nonlinear Distortion in Multicarrier Communication Systems

    Författare :Ali Behravan; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinearity; Multicarrier communication systems; peak-to-average power ratio;

    Sammanfattning : In modern wireless communication systems with increasing data transfer rateand mobility, designing efficient transceivers is a key issue. Among differentchallenges, nonlinearity of high power amplifiers is a problem that has to beovercome by means of adding extra hardware or using more efficient signalprocessing algorithms. LÄS MER