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Vincent H Poor - One of the best experts on this subject based on the ideXlab platform.
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rate splitting unifying sdma oma noma and Multicasting in miso broadcast channel a simple two user rate analysis
IEEE Wireless Communications Letters, 2020Co-Authors: Bruno Clerckx, Robert Schober, Vincent H PoorAbstract:Considering a two-user multi-antenna Broadcast Channel, this letter shows that linearly precoded Rate-Splitting (RS) with Successive Interference Cancellation (SIC) receivers is a flexible framework for non-orthogonal transmission that generalizes, and subsumes as special cases, four seemingly different strategies, namely Space Division Multiple Access (SDMA) based on linear precoding, Orthogonal Multiple Access (OMA), Non-Orthogonal Multiple Access (NOMA) based on linearly precoded superposition coding with SIC, and physical-layer Multicasting. This letter studies the sum-rate and shows analytically how RS unifies, outperforms, and specializes to SDMA, OMA, NOMA, and Multicasting as a function of the disparity of the channel strengths and the angle between the user channel directions.
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rate splitting unifying sdma oma noma and Multicasting in miso broadcast channel a simple two user rate analysis
arXiv: Information Theory, 2019Co-Authors: Bruno Clerckx, Robert Schober, Vincent H PoorAbstract:Considering a two-user multi-antenna Broadcast Channel, this paper shows that linearly precoded Rate-Splitting (RS) with Successive Interference Cancellation (SIC) receivers is a flexible framework for non-orthogonal transmission that generalizes, and subsumes as special cases, four seemingly different strategies, namely Space Division Multiple Access (SDMA) based on linear precoding, Orthogonal Multiple Access (OMA), Non- Orthogonal Multiple Access (NOMA) based on linearly precoded superposition coding with SIC, and physical-layer Multicasting. The paper studies the sum-rate and shows analytically how RS unifies, outperforms, and specializes to SDMA, OMA, NOMA, and Multicasting as a function of the disparity of the channel strengths and the angle between the user channel directions.
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multicast pushing with content request delay information
IEEE Transactions on Communications, 2018Co-Authors: Wei Chen, Vincent H PoorAbstract:Multicasting can reduce network traffic in multiuser systems by serving multiple users simultaneously. The benefits of Multicasting basically come from the overlapping and synchronism of user requests. Pushing and caching are techniques that prestore content items in buffers closer to users based on the prediction of user requests, thereby providing a promising approach to eliminating the asynchronism of user requests and creating Multicasting opportunities. This paper studies a multiuser wireless communication system, in which the buffers for caching are deployed in the user terminals. Based on the request delay information (RDI) which describes when the users request content items in a deterministic or statistical way, a joint pushing and caching (JPC) method is presented to schedule the content items pushed by the base station and cached in the user buffers. In this paper, Multicasting JPC systems work in two modes, without or with the feedback of RDI. Furthermore, RDI is classified into three forms, namely, noncausal, statistical, and causal. Static and dynamic JPC policies are, respectively, proposed for the two work modes. In addition, the effective throughput resulting from JPC under the three forms of RDI is demonstrated via theoretical analysis and simulation.
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on the spectral efficiency and security enhancements of noma assisted multicast unicast streaming
IEEE Transactions on Communications, 2017Co-Authors: Zhiguo Ding, Zhongyuan Zhao, Mugen Peng, Vincent H PoorAbstract:This paper considers the application of non-orthogonal multiple access (NOMA) to a multi-user network with mixed Multicasting and unicasting traffic. The proposed design of beamforming and power allocation ensures that the unicasting performance is improved while maintaining the reception reliability of Multicasting. Both analytical and simulation results are provided to demonstrate that the use of the NOMA assisted multicast-unicast scheme yields a significant improvement in spectral efficiency compared with orthogonal multiple access (OMA) schemes which realize Multicasting and unicasting services separately. Since unicast messages are broadcast to all the users, how the use of NOMA can prevent those multicast receivers intercepting the unicasting messages is also investigated, where it is shown that the secrecy unicasting rate achieved by NOMA is always larger than or equal to that of OMA. Simulation results are provided to verify the developed analytical results and demonstrate the superior performance of the proposed NOMA scheme.
He Yongqi - One of the best experts on this subject based on the ideXlab platform.
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Tunable optical Multicasting of PDM-OFDM signals by novel polarization-interleaved multi-pump FWM scheme
OPTICS EXPRESS, 2016Co-Authors: Zhu Paikun, Li Juhao, Chen Yuanxiang, Chen Zhangyuan, Zhou Peng, He YongqiAbstract:Optical Multicasting that supports point-to-multipoint traffic replication can be one of the necessary techniques in next-generation all-optical elastic networks. In this paper, we propose an optical Multicasting approach for polarization-division-multiplexing (PDM) orthogonal frequency division multiplexing (OFDM) signals based on a novel polarization-interleaved multi-pump (PIMP) four-wave mixing (FWM) scheme in highly nonlinear fiber (HNLF). Besides format transparency and the support of PDM signals, the scheme further enables wide spectral tunability of generated replicas. The pump frequency arrangement for the scheme is presented, which successfully prevents the replicas from being superimposed by unwanted FWM components during tuning. We experimentally demonstrate Multicasting operation of a 3-band 100-Gb/s PDM-OFDM signal. With different input positions, 1.4 and 1.6 Terahertz tuning ranges of four replicas are achieved with Q-factor performance better than the forward error correction threshold. Tunable replica spacing from 100-GHz to 250-GHz are also verified. In addition, the scalability of the scheme is demonstrated via 5-pump Multicasting, successfully generating a total of 14 replicas. (C) 2016 Optical Society of AmericaProgram 973 [2014CB340105]; Natural National Science Foundation of China (NSFC) [61505002, 61377072]; CPSF [2015M580926, 2016T90015]SCI(E)ARTICLEjuhao_li@pku.edu.cn2326344-263562
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Experimental demonstration of EON node supporting reconfigurable optical superchannel Multicasting
OPTICS EXPRESS, 2015Co-Authors: Zhu Paikun, Li Juhao, Chen Yuanxiang, Chen Xin, Wu Zhongying, Ge Dawei, Chen Zhangyuan, He YongqiAbstract:Elastic optical networks (EON) based on optical superchannel enables higher spectral flexibility, in which the network nodes should provide multiple all-optical functionalities to manipulate bandwidth-variable data traffic. In this paper, we propose and demonstrate an EON node structure supporting reconfigurable optical superchannel Multicasting. The node structure incorporates a shared Multicasting module, which performs reconfigurable selection of target incoming/outgoing superchannels/replicas and leverages a group of nonlinear devices to satisfy multiple multicast requests. Moreover, an optical comb is utilized to efficiently provide and manage all pump resources for Multicasting with potential cost reduction and phase noise inhibition. Based on the node structure, we experimentally demonstrate polarization division multiplexing (PDM) superchannel Multicasting scenarios with different replica amount, input/output locations, and modulation formats. Less than 0.7 dB optical signal-to-noise ratio (OSNR) penalties are demonstrated in multiple Multicasting scenarios. (C) 2015 Optical Society of AmericaNational Basic Research Program of China (973 Program) [2014CB340105, 2012CB315606]; NSFC [61377072, 61275071, 61205058]SCI(E)EIARTICLEjuhao_li@pku.edu.cn1620495-205042
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Recursive pump-adding scheme for optical superchannel Multicasting based on FWM
optics communications, 2015Co-Authors: Zhu Paikun, Li Juhao, Chen Xin, Wu Zhongying, Chen Zhangyuan, Xu Yingying, Lin Bangjiang, He YongqiAbstract:Optical superchannel Multicasting, whereby a superchannel is replicated simultaneously to multiple spectral locations in a single device, is potentially a promising functionality for future optical networks. Multiple-pump four-wave mixing (FWM) in highly nonlinear fiber (HNLF) is an effective approach to implement superchannel Multicasting. However, if the frequencies of the pumps are not carefully configured, the generated replicas would be spectrally scattered, which would increase the difficulty of controlling replicas' performance and managing spectral resource. In this paper, we propose a recursive pump-adding (RPA) scheme, which makes the replicas more spectrally aggregated than our previous exponentially-growing-spaced (EGS) pump scheme. Such replica aggregation technique can reduce phase mismatching of replicas remote from the original channel, which is beneficial to replicas' performance. RPA scheme also provides an additional option of replica allocation for Multicasting. Based on the RPA scheme, we have experimentally demonstrated 1-to-21 superchannel Multicasting with 5 pumps. More than 2.3 dB Q-factor margin is achieved across all the replicas compared with the typical 7% forward error correction (FEC) threshold. The performance comparison between RPA and EGS pump scheme is also investigated. ? 2015 Published by Elsevier B.V.SCI(E)EI0ARTICLEjuhao_li@pku.edu.cn25-3034
Urs Niesen - One of the best experts on this subject based on the ideXlab platform.
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decentralized coded caching attains order optimal memory rate tradeoff
Allerton Conference on Communication Control and Computing, 2013Co-Authors: Mohammad Ali Maddahali, Urs NiesenAbstract:Replicating or caching popular content in memories distributed across the network is a technique to reduce peak network loads. Conventionally, the main performance gain of this caching was thought to result from making part of the requested data available closer to end users. Instead, we recently showed that a much more significant gain can be achieved by using caches to create Multicasting opportunities, even for users with different demands, through coding across data streams. These simultaneous coded-Multicasting opportunities are enabled by careful content overlap at the various caches in the network, created by a central coordinating server. In many scenarios, such a central coordinating server may not be available, raising the question if this Multicasting gain can still be achieved in a more decentralized setting. In this paper, we propose an efficient caching scheme, in which the content placement is performed in a decentralized manner. In other words, no coordination is required for the content placement. Despite this lack of coordination, the proposed scheme is nevertheless able to create simultaneous coded-Multicasting opportunities, and hence achieves a rate close to the centralized scheme.
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decentralized coded caching attains order optimal memory rate tradeoff
arXiv: Information Theory, 2013Co-Authors: Mohammad Ali Maddahali, Urs NiesenAbstract:Replicating or caching popular content in memories distributed across the network is a technique to reduce peak network loads. Conventionally, the main performance gain of this caching was thought to result from making part of the requested data available closer to end users. Instead, we recently showed that a much more significant gain can be achieved by using caches to create coded-Multicasting opportunities, even for users with different demands, through coding across data streams. These coded-Multicasting opportunities are enabled by careful content overlap at the various caches in the network, created by a central coordinating server. In many scenarios, such a central coordinating server may not be available, raising the question if this Multicasting gain can still be achieved in a more decentralized setting. In this paper, we propose an efficient caching scheme, in which the content placement is performed in a decentralized manner. In other words, no coordination is required for the content placement. Despite this lack of coordination, the proposed scheme is nevertheless able to create coded-Multicasting opportunities and achieves a rate close to the optimal centralized scheme.
Stojan Radic - One of the best experts on this subject based on the ideXlab platform.
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suppression of inter channel higher order four wave mixing in four mode phase sensitive parametric wavelength Multicasting
Journal of Lightwave Technology, 2015Co-Authors: Lan Liu, Nikola Alic, Bill P P Kuo, E Myslivets, Andreas O. J. Wiberg, Stojan RadicAbstract:Phase manipulation of four-mode phase-sensitive (4MPS) process was developed as a means for suppression of high-order four wave mixing (HoFWM) terms in dual-pump driven parametric wavelength Multicasting and, consequently, for reduction of inter-channel crosstalk and inter-channel interference. In contrast to the previous studies that focused on power stabilization and conversion efficiency maximization, the investigation in this paper focuses on the evolution of the inter-channel HoFWM tones, whose suppression can be accomplished by arranging the phases of signals in a complementary manner. In addition, broadband 4MPS Multicasting with suppressed HoFWM effects over 100-nm bandwidth, reaching up to 12-dB suppression ratio was demonstrated.
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wavelength Multicasting via frequency comb generation in a bandwidth enhanced fiber optical parametric mixer
Journal of Lightwave Technology, 2011Co-Authors: Bill P P Kuo, Nikola Alic, E Myslivets, Stojan RadicAbstract:We demonstrate a self-seeded Multicasting device capable of delivering a large number of signal integrity preserving spectrally-distinct copies. The new Multicasting device relies on efficient higher-order mixing in a two-pump parametric mixer. Precise dispersion engineering was deployed to generate a frequency-comb spanning over a 140-nm band, and resulted in the creation of more than 60 spectral copies of the signal with conversion efficiencies higher than -3 dB. The fidelity of the Multicasting device with respect to signal intensity and phase was characterized experimentally. The spectral replication process was found to induce low penalty with both ON-OFF and differential phase-shift keying signals, thereby indicating compatibility with arbitrary amplitude/phase signaling formats.
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sampling of multiple 320 gb s channels by single parametric gate
IEEE Photonics Technology Letters, 2009Co-Authors: Andreas O. J. Wiberg, Nikola Alic, B. P.-p. Kuo, Camillesophie Bres, J X Zhao, Stojan RadicAbstract:All-optical Multicasting of a 320-Gb/s intensity-modulated return-to-zero signal with subsequent simultaneous sampling by a single parametric gate is experimentally demonstrated. The architecture used a two-pump broadband fiber-optic parametric amplifier for Multicasting, and a single 40-GHz optical parametric sampling gate in a highly nonlinear fiber. Using this architecture, we demonstrate parallel demultiplexing of four 320-Gb/s tributary channels. All demultiplexed channels were measured with a Q-factor better than 15 dB.
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scalable Multicasting in one pump parametric amplifier
OFC NFOEC 2008, 2009Co-Authors: Camillesophie Bres, E Myslivets, Nikola Alic, Stojan RadicAbstract:We report the experimental demonstration of all-optical wavelength Multicasting of OC-768 (40 Gbps) channel using a single-pass, pump modulated parametric amplifier. The performances of 1-to-20 and 1-to-40 Multicasting with excellent signal fidelity were observed. The impairment mechanisms were identified from cascaded filtering, linear and nonlinear crosstalk. It is shown that the parametric amplifier offers a wide range of operation characterized by minimal multicast penalty. We show that all multicast channels have an error free performance with Q factors well above the forward error correction (FEC) limit within the designed operating range.
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Multicast Parametric Synchronous Sampling of 320-Gb/s Return-to-Zero Signal
IEEE Photonics Technology Letters, 2009Co-Authors: Andreas O. J. Wiberg, Nikola Alic, Camillesophie Bres, JosÉ Chavez M. Boggio, Stojan RadicAbstract:Technology for simultaneous demultiplexing of subrate tributaries is described and applied to 320-Gb/s return-to-zero input. The parametric architecture is scalable with respect to processed input rate and relies on cascaded all-optical Multicasting and subrate sampling. Processing of 320-Gb/s input was achieved by creating eight channel copies, followed by a 20-THz-wide parametric gate. Multicasting was based on a self-seeded two-pump broadband fiber-optic parametric amplifier. The architecture was used to demonstrate error-free parallel demultiplexing of eight 320-Gb/s tributary channels at 40 Gb/s.
Dongdong Jiang - One of the best experts on this subject based on the ideXlab platform.
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analysis and optimization of caching and Multicasting in large scale cache enabled wireless networks
IEEE Transactions on Wireless Communications, 2016Co-Authors: Ying Cui, Dongdong JiangAbstract:Caching and Multicasting at base stations are two promising approaches to supporting massive content delivery over wireless networks. However, existing analysis and designs do not fully explore and exploit the potential advantages of the two approaches. In this paper, we consider the analysis and optimization of caching and Multicasting in a large-scale cache-enabled wireless network. We propose a random caching and Multicasting design. By carefully handling different types of interferers and adopting appropriate approximations, we derive a tractable expression for the successful transmission probability in the general region, utilizing tools from stochastic geometry. We also obtain a closed-form expression for the successful transmission probability in the high signal-to-noise ratio (SNR) and user density region. Then, we consider the successful transmission probability maximization, which is a very complex nonconvex problem in general. Using optimization techniques, we develop an iterative numerical algorithm to obtain a local optimal caching and Multicasting design in the general region. To reduce complexity and maintain superior performance, we also derive an asymptotically optimal caching and Multicasting design in the asymptotic region, based on a two-stage optimization framework. Finally, numerical simulations show that the asymptotically optimal design achieves a significant gain in successful transmission probability over some baseline schemes in the general region.
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analysis and optimization of caching and Multicasting in large scale cache enabled wireless networks
arXiv: Information Theory, 2015Co-Authors: Ying Cui, Dongdong JiangAbstract:Caching and Multicasting at base stations are two promising approaches to support massive content delivery over wireless networks. However, existing analysis and designs do not fully explore and exploit the potential advantages of the two approaches. In this paper, we consider the analysis and optimization of caching and Multicasting in a large-scale cache-enabled wireless network. We propose a random caching and Multicasting scheme with a design parameter. By carefully handling different types of interferers and adopting appropriate approximations, we derive a tractable expression for the successful transmission probability in the general region, utilizing tools from stochastic geometry. We also obtain a closed-form expression for the successful transmission probability in the high signal-to-noise ratio (SNR) and user density region. Then, we consider the successful transmission probability maximization, which is a very complex non-convex problem in general. Using optimization techniques, we develop an iterative numerical algorithm to obtain a local optimal caching and Multicasting design in the general region. To reduce complexity and maintain superior performance, we also derive an asymptotically optimal caching and Multicasting design in the asymptotic region, based on a two-step optimization framework. Finally, numerical simulations show that the asymptotically optimal design achieves a significant gain in successful transmission probability over some baseline schemes in the general region.
