The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Vincent Harold Poor - One of the best experts on this subject based on the ideXlab platform.
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orthogonal frequency division multiplexing with index modulation
IEEE Transactions on Signal Processing, 2013Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal Panayirci, Vincent Harold PoorAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, called OFDM with index modulation (OFDM-IM), is proposed for operation over frequency-selective and rapidly time-varying fading channels. In this scheme, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different low complexity transceiver structures based on maximum likelihood detection or log-likelihood ratio calculation are proposed and a theoretical error performance analysis is provided for the new scheme operating under ideal channel conditions. Then, the proposed scheme is adapted to realistic channel conditions such as imperfect channel state information and very high mobility cases by modifying the receiver structure. The approximate pairwise error probability of OFDM-IM is derived under channel estimation errors. For the mobility case, several interference unaware/aware detection methods are proposed for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to the information Bits carried by the indices of OFDM subcarriers under both ideal and realistic channel conditions.
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Orthogonal frequency division multiplexing with index modulation
2012 IEEE Global Communications Conference (GLOBECOM), 2012Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal Panayirci, Vincent Harold PoorAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, which is called OFDM with index modulation (OFDM-IM), is proposed for frequency-selective fading channels. In this scheme, inspiring from the recently introduced spatial modulation concept for multiple-input multiple-output (MIMO) channels, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different transceiver structures are proposed and a theoretical error performance analysis is provided for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to the information Bits carried in the spatial domain by the indices of OFDM subcarriers.
Ertugrul Basar - One of the best experts on this subject based on the ideXlab platform.
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BlackSeaCom - Generalized frequency division multiplexing with space and frequency index modulation
2017 IEEE International Black Sea Conference on Communications and Networking (BlackSeaCom), 2017Co-Authors: Ersin Ozturk, Ertugrul Basar, Hakan Ali ÇirpanAbstract:Generalized frequency division multiplexing (GFDM) has been regarded as one of the promising candidates for the physical layer (PHY) of fifth generation (5G) wireless networks. Multiple-input multiple-output (MIMO) friendliness is a key ability for a physical layer scheme to match the foreseen requirements of 5G wireless networks. On the other hand, index modulation (IM) concept, which relies on conveying additional information Bits through indices of certain transmit entities, is an emerging technique to provide better spectral efficiency. In this paper, a novel MIMO-GFDM system, which combines GFDM with space and frequency IM (SFIM) technique, is proposed. In the GFDM-SFIM scheme, the transmit antenna, the constellation mode and the classic constellation symbols are determined according to Incoming Bit Stream. The main contribution of the paper is the construction of the GFDM-SFIM system model including joint MIMO detection and GFDM demodulation performed by the GFDM-SFIM receiver. We evaluate the error performance of the GFDM-SFIM scheme as well as prove its superiority by making comparisons with the spatial modulation (SM) GFDM system and orthogonal frequency division multiplexing (OFDM) SFIM system for Rayleigh multipath fading channels.
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orthogonal frequency division multiplexing with index modulation
IEEE Transactions on Signal Processing, 2013Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal Panayirci, Vincent Harold PoorAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, called OFDM with index modulation (OFDM-IM), is proposed for operation over frequency-selective and rapidly time-varying fading channels. In this scheme, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different low complexity transceiver structures based on maximum likelihood detection or log-likelihood ratio calculation are proposed and a theoretical error performance analysis is provided for the new scheme operating under ideal channel conditions. Then, the proposed scheme is adapted to realistic channel conditions such as imperfect channel state information and very high mobility cases by modifying the receiver structure. The approximate pairwise error probability of OFDM-IM is derived under channel estimation errors. For the mobility case, several interference unaware/aware detection methods are proposed for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to the information Bits carried by the indices of OFDM subcarriers under both ideal and realistic channel conditions.
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BlackSeaCom - Orthogonal frequency division multiplexing with index modulation in the presence of high mobility
2013 First International Black Sea Conference on Communications and Networking (BlackSeaCom), 2013Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal PanaylrclAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, which is called OFDM with index modulation (OFDM-IM), is proposed for frequency-selective fading channels in the presence of high mobility. In this scheme, inspiring from the recently introduced spatial modulation concept for multiple-input multiple-output (MIMO) channels, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different low complexity transceiver structures based on maximum likelihood (ML) detection or log-likelihood ratio (LLR) calculation are proposed. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM.
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Orthogonal frequency division multiplexing with index modulation
2012 IEEE Global Communications Conference (GLOBECOM), 2012Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal Panayirci, Vincent Harold PoorAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, which is called OFDM with index modulation (OFDM-IM), is proposed for frequency-selective fading channels. In this scheme, inspiring from the recently introduced spatial modulation concept for multiple-input multiple-output (MIMO) channels, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different transceiver structures are proposed and a theoretical error performance analysis is provided for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to the information Bits carried in the spatial domain by the indices of OFDM subcarriers.
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GLOBECOM - Orthogonal frequency division multiplexing with index modulation
2012 IEEE Global Communications Conference (GLOBECOM), 2012Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal Panayirci, H. Vincent PoorAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, which is called OFDM with index modulation (OFDM-IM), is proposed for frequency-selective fading channels. In this scheme, inspiring from the recently introduced spatial modulation concept for multiple-input multiple-output (MIMO) channels, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different transceiver structures are proposed and a theoretical error performance analysis is provided for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to the information Bits carried in the spatial domain by the indices of OFDM subcarriers.
Erdal Panayirci - One of the best experts on this subject based on the ideXlab platform.
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HMWC - A new transmission technique: OFDM with index modulation
2014 International Workshop on High Mobility Wireless Communications, 2014Co-Authors: Erdal PanayirciAbstract:In this presentation, a novel orthogonal frequency division multiplexing (OFDM) scheme, which is called OFDM with index modulation (OFDM-IM), is proposed for frequency-selective fading and fast timer-varying channels. In this scheme, inspiring from the recently introduced spatial modulation concept for multiple-input multiple-output (MIMO) channels, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different transceiver structures are proposed and a theoretical error performance analysis is provided for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to fact that less ICI is generated in high mobility channels and that the information Bits are carried in the spatial domain by the indices of OFDM subcarriers.
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orthogonal frequency division multiplexing with index modulation
IEEE Transactions on Signal Processing, 2013Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal Panayirci, Vincent Harold PoorAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, called OFDM with index modulation (OFDM-IM), is proposed for operation over frequency-selective and rapidly time-varying fading channels. In this scheme, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different low complexity transceiver structures based on maximum likelihood detection or log-likelihood ratio calculation are proposed and a theoretical error performance analysis is provided for the new scheme operating under ideal channel conditions. Then, the proposed scheme is adapted to realistic channel conditions such as imperfect channel state information and very high mobility cases by modifying the receiver structure. The approximate pairwise error probability of OFDM-IM is derived under channel estimation errors. For the mobility case, several interference unaware/aware detection methods are proposed for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to the information Bits carried by the indices of OFDM subcarriers under both ideal and realistic channel conditions.
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Orthogonal frequency division multiplexing with index modulation
2012 IEEE Global Communications Conference (GLOBECOM), 2012Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal Panayirci, Vincent Harold PoorAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, which is called OFDM with index modulation (OFDM-IM), is proposed for frequency-selective fading channels. In this scheme, inspiring from the recently introduced spatial modulation concept for multiple-input multiple-output (MIMO) channels, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different transceiver structures are proposed and a theoretical error performance analysis is provided for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to the information Bits carried in the spatial domain by the indices of OFDM subcarriers.
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GLOBECOM - Orthogonal frequency division multiplexing with index modulation
2012 IEEE Global Communications Conference (GLOBECOM), 2012Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal Panayirci, H. Vincent PoorAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, which is called OFDM with index modulation (OFDM-IM), is proposed for frequency-selective fading channels. In this scheme, inspiring from the recently introduced spatial modulation concept for multiple-input multiple-output (MIMO) channels, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different transceiver structures are proposed and a theoretical error performance analysis is provided for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to the information Bits carried in the spatial domain by the indices of OFDM subcarriers.
Umit Aygolu - One of the best experts on this subject based on the ideXlab platform.
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orthogonal frequency division multiplexing with index modulation
IEEE Transactions on Signal Processing, 2013Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal Panayirci, Vincent Harold PoorAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, called OFDM with index modulation (OFDM-IM), is proposed for operation over frequency-selective and rapidly time-varying fading channels. In this scheme, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different low complexity transceiver structures based on maximum likelihood detection or log-likelihood ratio calculation are proposed and a theoretical error performance analysis is provided for the new scheme operating under ideal channel conditions. Then, the proposed scheme is adapted to realistic channel conditions such as imperfect channel state information and very high mobility cases by modifying the receiver structure. The approximate pairwise error probability of OFDM-IM is derived under channel estimation errors. For the mobility case, several interference unaware/aware detection methods are proposed for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to the information Bits carried by the indices of OFDM subcarriers under both ideal and realistic channel conditions.
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BlackSeaCom - Orthogonal frequency division multiplexing with index modulation in the presence of high mobility
2013 First International Black Sea Conference on Communications and Networking (BlackSeaCom), 2013Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal PanaylrclAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, which is called OFDM with index modulation (OFDM-IM), is proposed for frequency-selective fading channels in the presence of high mobility. In this scheme, inspiring from the recently introduced spatial modulation concept for multiple-input multiple-output (MIMO) channels, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different low complexity transceiver structures based on maximum likelihood (ML) detection or log-likelihood ratio (LLR) calculation are proposed. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM.
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Orthogonal frequency division multiplexing with index modulation
2012 IEEE Global Communications Conference (GLOBECOM), 2012Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal Panayirci, Vincent Harold PoorAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, which is called OFDM with index modulation (OFDM-IM), is proposed for frequency-selective fading channels. In this scheme, inspiring from the recently introduced spatial modulation concept for multiple-input multiple-output (MIMO) channels, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different transceiver structures are proposed and a theoretical error performance analysis is provided for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to the information Bits carried in the spatial domain by the indices of OFDM subcarriers.
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GLOBECOM - Orthogonal frequency division multiplexing with index modulation
2012 IEEE Global Communications Conference (GLOBECOM), 2012Co-Authors: Ertugrul Basar, Umit Aygolu, Erdal Panayirci, H. Vincent PoorAbstract:In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, which is called OFDM with index modulation (OFDM-IM), is proposed for frequency-selective fading channels. In this scheme, inspiring from the recently introduced spatial modulation concept for multiple-input multiple-output (MIMO) channels, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the Incoming Bit Stream. Different transceiver structures are proposed and a theoretical error performance analysis is provided for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to the information Bits carried in the spatial domain by the indices of OFDM subcarriers.
Ming-ting Sun - One of the best experts on this subject based on the ideXlab platform.
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Video transcoder architectures for networked multimedia applications
2000Co-Authors: Jeongnam Youn, Ming-ting SunAbstract:For the deployment of multimedia services over heterogeneous networks, it is very desirable that a video delivery system be able to dynamically adapt the Bit-rate of a video Bit-Stream to the time-varying network conditions, such as the available bandwidth. A video transcoder which can adapt the Bit-rate of a video Bit-Stream and support various content. manipulations, error-resilience, and video watermarking insertion will improve the overall performance of multimedia systems. In this dissertation, we investigate various issues regarding transcoder architectures for networked multimedia applications. We first investigate existing fast architectures and analyze potential problems and limitations. We show that due to inherent but often ignored assumptions in the derivation, the existing fast architectures have severe limitations in practical applications. We also propose a fast transcoder scheme which does not have the limitations and problems of the existing fast transcoder architectures and can achieve drift-free performance with similar processing speed as the existing fast transcoders. In the proposed architecture, drift-error is prevented by adopting a pixel-domain cascaded structure. To reduce the computational cost in transcoding, several stages of computational blocks, such as Discrete Cosine Transform (DCT), Inverse DCT (IDCT), quantization, and inverse quantization are optimized. We also extend the transcoding function to applications. of a logo insertion. We consider the case when transcoding is necessary in the logo insertion process to reduce the Bit-rate. As many multimedia services are deployed in the Internet environment, the video delivery system requires a more intelligent and sophisticated Bit-rate adaptation scheme with a high transcoding ratio because of the wide range of operating bandwidths of the current Internet infrastructure. Down-conversions of frame-rates or picture resolutions can be effectively used for achieving a high transcoding ratio while maintaining an acceptable video quality. For this temporal and resolution transcoding, we propose a fast-motion vector refinement scheme to obtain the outgoing motion vectors from the motion vectors extracted from the Incoming Bit-Stream. Simulation results show that significant computational saving is possible while achieving almost the same video quality compared with that of using full-scale motion estimation.
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otion Vector Refinement for High Performance Transcoding
1998Co-Authors: Jeongnam Youn, Ming-ting SunAbstract:In transcoding, simple reuse of the motion vectors extracted from the Incoming Bit-Stream may introduce severe quality degradation in many applications. la this papei; weJirst discuss the effect of quantization error on the motion vectors. We show that due to the quantization errors, the Incoming motion vectors become non-optimal. To achieve the best quality possible, a new motion estimation should be pe~ormed in the transcoder We proposed an adaptive motion vector refinement scheme with a highly reduced computational complexity in comparison to the full-scale motion estimation. We also discuss the case when some Incoming frames are dropped for the frame-rate conversion. We propose a simple and fast motion vector interpolation method. We show that the proposed adaptive refinement scheme provides video quality almost as good as that can be achieved by performing a new full-scale motion estimation but requires much less computation.
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ISCAS - Fast video transcoding architectures for networked multimedia applications
2000 IEEE International Symposium on Circuits and Systems. Emerging Technologies for the 21st Century. Proceedings (IEEE Cat No.00CH36353), 1Co-Authors: Jeongnam Youn, Jun Xin, Ming-ting SunAbstract:In various networked multimedia applications, it is often necessary to change the Bit-rate and format of a pre-encoded Bit-Stream. This can be achieved using a cascaded pixel-domain transcoder, which fully decodes an Incoming Bit-Stream and then re-encodes the decoded pictures with the desired Bit-rate or format. However, the cascaded pixel-domain transcoder is computationally expensive. To reduce the computations, several fast architectures have been proposed in the literature. However, these fast transcoder architectures introduce new limitations and are not drift-free. In this paper, we propose new techniques to implement a fast cascaded pixel-domain transcoder. We further discuss the limitation and speed of the different transcoder architectures. We also discuss the methods for adding watermark or company logo, using the different transcoder architectures.
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ICIP (3) - Adaptive motion vector refinement for high performance transcoding
Proceedings 1998 International Conference on Image Processing. ICIP98 (Cat. No.98CB36269), 1Co-Authors: Jeongnam Youn, Ming-ting SunAbstract:In transcoding, simple reuse of the motion vectors extracted from the Incoming Bit-Stream may introduce severe quality degradation in many applications. In this paper we first discuss the effect of quantization error on the motion vectors. We show that due to the quantization errors, the Incoming motion vectors become non-optimal. To achieve the best quality possible, a new motion estimation should be performed in the transcoder. We proposed an adaptive motion vector refinement scheme with a highly reduced computational complexity in comparison to the full-scale motion estimation. We also discuss the case when some Incoming frames are dropped for the frame-rate conversion. We propose a simple and fast motion vector interpolation method. We show that the proposed adaptive refinement scheme provides video quality almost as good as that can be achieved by performing a new full-scale motion estimation but requires much less computation.
