Results 31 to 40 of about 4,021,406 (264)
Enhanced Optical-OFDM With Index and Dual-Mode Modulation for Optical Wireless Systems
IEEE Access, 2020 In this article, we introduce intensity modulation and direct detection compatible enhanced optical-orthogonal frequency division multiplexing with index modulation (EO-OFDM-IM) schemes.
Ali Waqar Azim +3 more
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Polar-Coded OFDM With Index Modulation
IEEE Access, 2021 In this paper, we apply polar codes to a modified version of OFDM systems with index modulation which is called OFDM with in-phase/quadrature index modulation (OFDM-I/Q-IM).
Si-Yu Zhang, Behnam Shahrrava
doaj +1 more source
A joint denoising and deep learning detector for OFDM‐IM
IET Communications, 2023 Abstract Only a subset of subcarriers are activated in orthogonal frequency division multiplexing‐index modulation (OFDM‐IM), which achieves higher energy efficiency and resists frequency offset. In the OFDM‐IM, the energy of the received signal is computed and then combined with pre‐processed signal to create the input of detection ...
Sirui Duan +4 more
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Enhanced Index Modulated OFDM Spread Spectrum
IEEE Access, 2018 Index modulated OFDM spread spectrum (OFDM-IM-SS) is a recently proposed scheme, which transmits the additional bits (index bits) through the code domain.
Jun Li +4 more
doaj +1 more source
Secure Index and Data Symbol Modulation for OFDM-IM [PDF]
IEEE Access, 2017 In this paper, we propose a secure index and data symbol modulation scheme for orthogonal frequency division multiplexing with index modulation (OFDM-IM) systems. By exploiting the notion of the channel reciprocity in time division duplexing mode over wireless channels for shared channel state information as a secret key, we investigate randomized ...
Yonggu Lee +3 more
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Joint Phase Noise Estimation and Decoding in OFDM-IM [PDF]
GLOBECOM 2020 - 2020 IEEE Global Communications Conference, 2020 This paper proposes a low-complexity joint phase noise (PHN) estimation and decoding algorithm for orthogonal frequency division multiplexing relying on index modulation (OFDM-IM) systems. A factor graph (FG) is constructed based on the truncated discrete cosine transform (DCT) expansion model for the variation of PHN.
Qiaolin Shi +4 more
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Space-Time Multiple-Mode Orthogonal Frequency Division Multiplexing With Index Modulation
IEEE Access, 2017 Multiple-mode orthogonal frequency division multiplexing with index modulation (MM-OFDM-IM) improves the spectral efficiency of the conventional OFDM-IM scheme by considering multiple distinguishable constellations for signal modulation.
Jun Li +3 more
doaj +1 more source
On the Phase Sequences and Permutation Functions in the SLM Scheme for OFDM-IM Systems
IEEE Access, 2020 In orthogonal frequency division multiplexing with index modulation (OFDM-IM), the active subcarriers can convey information bits by modulated symbols as well as their indices. OFDM-IM has attracted a great deal of attention from researchers by virtue of
Kee-Hoon Kim
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Robust OFDM timing synchronisation [PDF]
, 2005 A new pre-FFT synchronization method for OFDM is proposed and assessed that gives improved performance in multipath channels. The technique can be used for a range of OFDM signal parameters, and channel environments.
Williams, C +5 more
core +1 more source
Information Guided Precoding for OFDM
IEEE Access, 2017 In conventional orthogonal frequency division multiplexing with index modulation (OFDM-IM), the M-ary modulated symbols are transmitted on a subset of subcarriers under the guidance of information bits. In this paper, a novel information guided precoding
Qiang Li +3 more
doaj +1 more source