Results 51 to 60 of about 8,421 (222)
EURASIP Journal on Wireless Communications and Networking, 2009 The problem of multiservice transmission in OFDMA-based cooperative relay networks is studied comprehensively. We propose a framework to adaptively allocate power, subcarriers, and data rate in OFDMA system to maximize spectral efficiency under the ...
Wenbo Wang, Shuping Chen, Xing Zhang
doaj +2 more sources
A NEW DISCRETE HARTLEY TRANSFORM PRECODING BASED INTERLEAVED-OFDMA UPLINK SYSTEM WITH REDUCED PAPR FOR 4G CELLULAR NETWORKS [PDF]
Journal of Engineering Science and Technology, 2011 High peak-to-average power ratio (PAPR) reduction is one of the major challenges in orthogonal frequency division multiple access (OFDMA) systems since last decades. High PAPR increases the complexity of analogue-to-digital (A/D) and digital-to-analogue (
VARUN JEOTI, IMRAN BAIG
doaj
Generalized Network-Coded Cooperation in OFDMA Communications
IEEE Access, 2018 Cooperative communication is a well-established technique to obtain diversity and consequently combat the fading inherent to the wireless channel. In a recent work, network-coded cooperation (NCC) along with graph theory-aided subcarrier allocation was ...
Zaqueu Cabral Pereira +4 more
doaj +1 more source
An Efficient Backoff Procedure for IEEE 802.11ax Uplink OFDMA-Based Random Access
IEEE Access, 2022 IEEE 802.11ax stations can use multi-user (MU) uplink OFDMA-based random access (UORA) to improve per-station throughput in dense deployments in comparison to legacy IEEE 802.11 single-user access.
Katarzyna Kosek-Szott, Krzysztof Domino
doaj +1 more source
Energy harvesting for secure OFDMA systems [PDF]
2014 Sixth International Conference on Wireless Communications and Signal Processing (WCSP), 2014 Energy harvesting and physical-layer security in wireless networks are of great significance. In this paper, we study the simultaneous wireless information and power transfer (SWIPT) in downlink orthogonal frequency-division multiple access (OFDMA) systems, where each user applies power splitting to coordinate the energy harvesting and information ...
Meng Zhang 0013 +2 more
openaire +2 more sources
Performance evaluation of mobile WiMAX with MIMO and relay extensions [PDF]
, 2007 The latest mobile WiMAX standard promises to deliver high data rates over extensive areas and to large user densities. More specifically, data rates are expected to exceed those of conventional cellular technologies.
Nix, AR, Bian, YQ, Sun, Y, Strauch, P
core +1 more source
A precoded OFDMA system with user cooperation [PDF]
2008 42nd Annual Conference on Information Sciences and Systems, 2008 A new cooperative scheme for a two-user orthogonal frequency division multiple access (OFDMA) uplink communication scenario is proposed. Each user is equipped with one transmit/receive antenna. Before transmission, inter-block linear precoding is introduced to pairs of blocks.
Yao Yu 0004 +2 more
openaire +4 more sources
Robust Spectral and Energy Efficiency Tradeoff for RIS‐Aided Multi‐User Communication
IET Communications, Volume 20, Issue 1, January/December 2026.In this work, an RIS‐aided multi‐user network with imperfect CSI is investigated. Correspondingly, we focus on balancing SE and EE through the collaborative design of the base station (BS)'s precoding matrix and the RIS's phase shifts, which consider the transmit power budget and the channel uncertainties constraints.
Xiandeng He, Yilin Wang, Shun Zhang
wiley +1 more source
Adaptive Video Transmission for OFDMA Systems [PDF]
Multimedia and Expo, 2007 IEEE International Conference on, 2007 An adaptive framework is proposed for multi-user video transmission over orthogonal frequency division multiple access (OFDMA) systems. Utilizing the channel knowledge, a two-step heuristic sub-carrier assignment algorithm is proposed to achieve unequal error protection for the video data.
Guang-Hua Yang +2 more
openaire +2 more sources
IET Communications, Volume 20, Issue 1, January/December 2026.This paper investigates new radio spectrum coexistence mechanisms, leveraging the currently uninhabited 6 GHz bands and aiming for fair coexistence of Wi‐Fi 6 and 5G new radio unlicensed (NR‐U). A novel two‐stage channel contention mechanism is proposed to explore additional spectrum access opportunities which remain unrealized in the existing channel ...
Md Toufiqur Rahman +2 more
wiley +1 more source