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Mostrando ítems 11-20 de 36
Time-Modulated Arrays With Haar Wavelets
(Institute of Electrical and Electronics Engineers, 2020-11)
[Abstract]. Time-modulated arrays (TMAs) can effectively perform beamsteering over the first positive harmonic pattern by applying progressively delayed versions of stair-step approximations of a sine waveform to the antenna ...
Time-modulated array beamforming with periodic stair-step pulses
(Elsevier, 2020-01)
[Abstract]: Time-modulated arrays (TMAs) are able to improve the side-lobe level of the radiation pattern at the fundamental mode but cannot steer the beam at such a mode towards a given direction. Beam-steering is possible ...
Design and implementation of an OFDMA-TDD physical layer for WiMAX applications
(SpringerOpen & European Association for Signal Processing, 2013)
[Abstract]: This work describes the design, implementation, and performance evaluation of an orthogonal frequency division multiple access (OFDMA) time-division duplexing (TDD) physical layer (PHY) compliant with the ...
Time-Modulated Multibeam Phased Arrays With Periodic Nyquist Pulses
(Institute of Electrical and Electronics Engineers, 2018-12)
[Abstract]: We present a single sideband time-modulated multibeam phased array governed by periodic Nyquist pulsed signals. A Nyquist pulse is a physically realizable approach to the ideal sinc function. Hence, its low-pass ...
Analog Beamforming Using Time-Modulated Arrays With Digitally Preprocessed Rectangular Sequences
(Institute of Electrical and Electronics Engineers, 2018-03)
[Abstract]: Conventional time-modulated arrays are based on the application of variable-width periodical rectangular pulses (easily implemented with radio frequency switches) to the individual antenna excitations. However, ...
Time-Modulated Phased Array Controlled With Nonideal Bipolar Squared Periodic Sequences
(Institute of Electrical and Electronics Engineers, 2019-02)
[Abstract]: Bipolar (±1) sequences with no zero state suit particularly well for safeguarding the switched feeding network efficiency when applied to time-modulated arrays. During the zero state of a conventional time-modulating ...
Dual-Signal Transmission Using RF Precoding and Analog Beamforming With TMAs
(IEEE, 2018-06)
[Absctract]: Time-modulated arrays (TMAs) receiving beamforming provide a noteworthy hardware simplicity given the ability of this multi-antenna technique to transform spatial diversity into frequency diversity. However, ...
Direct Antenna Frequency-Hopped M-FSK Modulation With Time-Modulated Arrays
(Institute of Electrical and Electronics Engineers, 2024-02)
[Abstract]: We present an innovative approach that simultaneously enables direct antenna frequency-hopped M-ary frequency shift keying (DAFH-MFSK) modulation and beamsteering through the use of time-modulated arrays (TMAs). ...
TMA–FDA Range-Angle Beamforming With Periodic Linear-Phase Time-Modulating Waveforms
(Institute of Electrical and Electronics Engineers, 2022)
[Abstract]: Frequency diverse arrays (FDAs) provide range-angle time-invariant transmit–receive beamforming, although a fine focus of their radiation patterns is costly since high-resolution mixers and phase shifters are ...
Experimental Characterization of LTE Wireless Links in High-Speed Trains
(Hindawi, 2017)
[Abstract]: Multimedia and data-based services experienced a nonstopping growth over the last few years. People are continuously on the move using devices to access multimedia contents or other data-based services. Due to ...