Sökning: "Fading kanal"

Hittade 5 uppsatser innehållade orden Fading kanal.

  1. 1. Channel Estimation and Power Control Algorithms in the Presence of Channel Aging

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Yan Bixing; [2023]
    Nyckelord :Fading channel; auto-regressive model; power allocation; uncrewed aerial vehicle networks; Fading kanal; auto-regressiv modell; krafttilldelning; obemannade flygfordonsnätverk;

    Sammanfattning : Power allocation algorithms that determine how much power should be allocated to pilot and data symbols play an important role in addressing the trade-off between accurate channel estimation and high high spectral efficiency for data symbols in the presence of time-varying fading channels. Dealing with this trade-off is highly non-trivial when the channel changes or ages rapidly in time. LÄS MER

  3. 2. Cell Acquisition and Synchronization for Unlicensed NB-IoT

    Master-uppsats, Linköpings universitet/Kommunikationssystem

    Författare :Eskil Jörgensen; [2017]
    Nyckelord :Narrowband Internet-of-Things; NB-IoT; unlicensed; cell search; cell acquisition; synchronization; artificial fast fading; binary sequences; peak sidelobe level;

    Sammanfattning : Narrowband Internet-of-Things (NB-IoT) is a new wireless technology designed to support cellular networks with wide coverage for a massive number of very cheap low power user devices. Studies have been initiated for deployment of NB-IoT in unlicensed frequency bands, some of which demand the use of a frequency-hopping scheme with a short channel dwell time. LÄS MER

  4. 3. Optimal Power Allocation and Ergodic Capacity in Cognitive Radio Network

    Master-uppsats, KTH/Skolan för elektro- och systemteknik (EES)

    Författare :Guanren Wen; [2016]
    Nyckelord :;

    Sammanfattning : Cognitive radio network allows the secondary users (SUs) in a secondary communication network (SCN) coexist with priority users in a priority communication network (PCN). The interference caused by SCN to PCN is required to be rational and not affected the quality of server within the PCN to each priority users (PUs). LÄS MER

  5. 4. Hybrid Power Control in Time Division Scheduling Wideband Code Division Multiplex Access

    Master-uppsats, KTH/Kommunikationssystem, CoS

    Författare :Zhuo Cheng; [2011]
    Nyckelord :WCDMA; High-Speed Uplink Packet Access; Power Control; unused code GRAKE;

    Sammanfattning : With high date rates using Enhanced Uplink (EUL), a conventional signal to interference ratio (SIR) based power control algorithm may lead to a power rush due to self interference or incompatible SIR target [2]. Time division (TD) scheduling in Wideband Code Division Multiplex Access (WCDMA) is considered to be a key feature in achieving high user data rates. LÄS MER

  7. 5. PERFORMANCE ANALYSIS ON MODULATION TECHNIQUES OF W-CDMA IN MULTIPATH FADING CHANNEL

    Master-uppsats, Blekinge Tekniska Högskola/Avdelningen för signalbehandling

    Författare :AUN ALI TAHIR; FENG ZHAO; [2009]
    Nyckelord :Final Thesis as Part for Master program in Electrical Engineering with Emphasis on Telecommunication;

    Sammanfattning : The transmission from base station to mobile or downlink transmission using M-ary Quadrature Amplitude modulation (QAM) and Quadrature phase shift keying (QPSK) modulation scheme are consider in W-CDMA system. We can analysis the performance of these modulation techniques when the system is subjected to AWGN and multipath Rayleigh fading are consider in the channel. LÄS MER