| 1. |
- Li, A., et al.
(författare)
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A Tutorial on Interference Exploitation via Symbol-Level Precoding : Overview, State-of-the-Art and Future Directions
- 2020
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Ingår i: IEEE Communications Surveys and Tutorials. - : Institute of Electrical and Electronics Engineers (IEEE). - 1553-877X. ; 22:2, s. 796-839
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Tidskriftsartikel (refereegranskat)abstract
- Interference is traditionally viewed as a performance limiting factor in wireless communication systems, which is to be minimized or mitigated. Nevertheless, a recent line of work has shown that by manipulating the interfering signals such that they add up constructively at the receiver side, known interference can be made beneficial and further improve the system performance in a variety of wireless scenarios, achieved by symbol-level precoding (SLP). This paper aims to provide a tutorial on interference exploitation techniques from the perspective of precoding design in a multi-antenna wireless communication system, by beginning with the classification of constructive interference (CI) and destructive interference (DI). The definition for CI is presented and the corresponding mathematical characterization is formulated for popular modulation types, based on which optimization-based precoding techniques are discussed. In addition, the extension of CI precoding to other application scenarios as well as for hardware efficiency is also described. Proof-of-concept testbeds are demonstrated for the potential practical implementation of CI precoding, and finally a list of open problems and practical challenges are presented to inspire and motivate further research directions in this area.
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| 2. |
- Li, J., et al.
(författare)
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One-bit soft forwarding for network coded uplink channels with multiple sources
- 2014
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Ingår i: 2014 IEEE International Conference on Communications, ICC 2014. - : IEEE Computer Society. - 9781479920037 ; , s. 5790-5795
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Konferensbidrag (refereegranskat)abstract
- In this paper, we propose a threshold-based one-bit soft forwarding (TOB-SF) protocol for a multi-source relaying uplink system with network coding. In the TOB-SF protocol, the relay calculates the log-likelihood ratio (LLR) value of each network coded symbol, compares this LLR value with a pre-optimized threshold, and determines whether to transmit or keep silent. We first derive the bit error rate (BER) expression at the destination, based on which, we optimize the threshold to minimize the BER. Then we theoretically prove that the system can achieve the full diversity gain by using this threshold. Further, we optimize the power allocation at the relay to achieve a higher coding gain. Simulation results show that the proposed TOB-SF protocol outperforms other conventional relaying protocols in terms of error performance.
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| 3. |
- Liu, W., et al.
(författare)
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Remote State Estimation with Smart Sensors over Markov Fading Channels
- 2022
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Ingår i: IEEE Transactions on Automatic Control. - : Institute of Electrical and Electronics Engineers Inc.. - 0018-9286 .- 1558-2523. ; 67:6, s. 2743-2757
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Tidskriftsartikel (refereegranskat)abstract
- We consider a fundamental remote state estimation problem of discrete-time linear time-invariant (LTI) systems. A smart sensor forwards its local state estimate to a remote estimator over a time-correlated multi-state Markov fading channel, where the packet drop probability is time-varying and depends on the current fading channel state. We establish a necessary and sufficient condition for mean-square stability of the remote estimation error covariance in terms of the state transition matrix of the LTI system, the packet drop probabilities in different channel states, and the transition probability matrix of the Markov channel states. To derive this result, we propose a novel estimation-cycle based approach, and provide new elementwise bounds of matrix powers. The stability condition is verified by numerical results, and is shown more effective than existing sufficient conditions in the literature.We observe that the stability region in terms of the packet drop probabilities in different channel states can either be convex or non-convex depending on the transition probability matrix of the Markov channel states. Our numerical results suggest that the stability conditions for remote estimation may coincide for setups with a smart sensor and with a conventional one (which sends raw measurements to the remote estimator), though the smart sensor setup achieves a better estimation performance.
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| 4. |
- Liu, W., et al.
(författare)
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Stability Conditions for Remote State Estimation of Multiple Systems over Multiple Markov Fading Channels
- 2022
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Ingår i: IEEE Transactions on Automatic Control. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9286 .- 1558-2523. ; , s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the stability conditions for remote state estimation of multiple linear time-invariant (LTI) systems over multiple wireless time-varying communication channels. We answer the following open problem: what is the fundamental requirement on the multi-sensor-multi-channel system to guarantee the existence of a sensor scheduling policy that can stabilize the remote estimation system? We propose a novel policy construction and analytical framework and derive the necessary-and-sufficient stability condition in terms of the LTI system parameters and the channel statistics.
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| 5. |
- Yue, J., et al.
(författare)
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Performance analysis of distributed raptor codes in wireless relay networks
- 2014
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Ingår i: 2014 11th Annual IEEE International Conference on Sensing, Communication, and Networking, SECON 2014. - 9781479946570 ; , s. 221-229
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Konferensbidrag (refereegranskat)abstract
- In this paper, we propose a distributed network coding (DNC) scheme based on the Raptor codes for wireless relay networks (WRNs), where a group of source nodes communicate with a single sink through a common relay network in a multi-hop fashion. At the sink, a graph-based Raptor code is formed on the fly. After receiving a sufficient number of encoded packets, the sink begins to decode. The main contributions of this paper are the derivations of upper and lower bit error rate (BER) bounds for the proposed Raptor-based DNC scheme.
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| 6. |
- Yue, J., et al.
(författare)
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Performance Analysis of Distributed Raptor Codes in Wireless Sensor Networks
- 2013
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Ingår i: IEEE Transactions on Communications. - : Institute of Electrical and Electronics Engineers (IEEE). - 0090-6778 .- 1558-0857. ; 61:10, s. 4357-4368
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we propose a distributed network coding (DNC) scheme based on the Raptor codes for wireless sensor networks (WSNs), where a group of sensor nodes, acting as source nodes, communicate with a single sink through some other sensor nodes, serving as relay nodes, in a multi-hop fashion. At the sink, a graph-based Raptor code is formed on the fly. After receiving a sufficient number of encoded packets, the sink begins to decode. The main contributions of this paper are the derivation of a bit error rate (BER) lower bound for the LT-based DNC scheme over Rayleigh fading channels under maximum-likelihood (ML) decoding, and the derivations of upper and lower BER bounds for the proposed Raptor-based DNC scheme on the basis of the derived BER bound of LT codes.
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