| 1. |
- Do, Hieu, et al.
(författare)
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A new inner bound for the interference relay channel
- 2012
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Ingår i: 2012 46th Annual Conference on Information Sciences and Systems, CISS 2012. - : IEEE. - 9781467331401 ; , s. 6310756-
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a new coding scheme for the discrete memoryless interference channel with a dedicated relay. The scheme is built upon rate-splitting encoding, layered noisy network coding, and joint decoding. The result is extended to two Gaussian channels. For the Gaussian channel whose relay is connected to the destinations via orthogonal links we indirectly show that the proposed scheme achieves a bounded gap to the capacity region under certain channel conditions. For the Gaussian channel wherein the relay receives and transmits in the same spectral resource with the transmitters the numerical results show that the proposed scheme achieves higher sum rate than other compress-forward-based schemes. This work, together with our previous work [1], shows that noisy network coding can be extended by the well-known rate-splitting technique of the interference channel to achieve a bounded gap to the capacity region of some multi-unicast networks.
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| 2. |
- Do, Hieu, et al.
(författare)
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An Achievable Rate Region for the Gaussian Z-interference Channel with Conferencing
- 2009
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Ingår i: 2009 47TH ANNUAL ALLERTON CONFERENCE ON COMMUNICATION, CONTROL, AND COMPUTING, VOLS 1 AND 2. - NEW YORK : IEEE. ; , s. 75-81
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Konferensbidrag (refereegranskat)abstract
- This paper presents an achievable rate region for a 2-user Gaussian Z-interference channel with a noiseless and bidirectional digital communication link between the receivers. The region is achieved by utilizing the rate-splitting encoding technique, and the decode-and-forward and compress-and-forward strategies. In the very strong interference regime, the capacity region is achieved. In the weak interference regime, the asymptotic sum rate is characterized and shown to be possibly unbounded, which is in contrast to a recent result by Yu and Zhou for a similar scenario, however, with a unidirectional communication link between the receivers.
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| 3. |
- Do, Hieu, et al.
(författare)
-
Capacity bounds for the Z channel
- 2011
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Ingår i: IEEE Information Theory Workshop (ITW), 2011. - 9781457704383
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Konferensbidrag (refereegranskat)abstract
- We present a new achievable rate region for the discrete memoryless Z channel (DM-ZC) using Marton coding with rate splitting. The region is shown to include previously known achievable rate regions. Secondly we study a class of degraded Z channels, the bijective degraded Z channel (BDZC). An outer bound for the BDZC is proved, which is shown to meet the inner bound for the deterministic settings. For the Gaussian Z channel with weak crossover link, we show that if Gaussian inputs are optimal then a coding scheme based on Marton coding without rate splitting achieves to within half a bit per real dimension from the boundary of the capacity region.
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| 4. |
- Do, Hieu, et al.
(författare)
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Capacity Region of a Class of Interfering Relay Channels
- 2013
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Ingår i: 2013 IEEE Information Theory Workshop (ITW). - : IEEE. - 9781479913237 ; , s. 6691350-
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Konferensbidrag (refereegranskat)abstract
- This paper studies a new model for cooperative communication, the interfering relay channels. We show that thehash-forward scheme introduced by Kim for the primitive relay channel is capacity achieving for a class of semideterministic interfering relay channels. The obtained capacity result generalizes and unifies earlier capacity results for a class of primitive relay channels and a class of deterministic interference channels.
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| 5. |
- Do, Hieu, et al.
(författare)
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Coding for the Z Channel With a Digital Relay Link
- 2010
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Ingår i: 2010 IEEE Information Theory Workshop, ITW 2010 - Proceedings. - 9781424482627 - 9781424482634
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Konferensbidrag (refereegranskat)abstract
- This paper considers a discrete memoryless four-node network where two nodes want to send three independent messages to the other two nodes. The two receiving nodes are allowed to cooperate by means of a unidirectional noiseless link with finite capacity. A coding scheme is proposed which combines rate splitting, block Markov multi-level superposition coding with binning and joint decoding. The general achievable rates are then specialized to degraded channel and Gaussian channel, where it is shown that the sum capacity for the Gaussian channel is achieved under certain conditions. Results in this paper recover and unify previously known results for the discrete memoryless Z channel without cooperation, and results for the Gaussian Z-interference channel with a digital relay link.
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| 6. |
- Do, Hieu, 1980-
(författare)
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Fundamental Aspects of Cooperative Interference Management
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Today and future wireless networks are facing one of their greatest limiting factors:interference. This is due to the unprecedented increase in the number of connecteddevices. Therefore, in order to meet the ever increasing demand for data rate andquality of services, more advanced techniques than what we have today are requiredto deal with interference. This thesis takes a step towards interference managementin multiuser wireless systems by means of relaying and cooperation. We study fourfundamental building blocks in network information theory, propose new codingschemes, and derive limits on the capacity regions.The first problem we consider is the one-sided interference channel with bidirectional and rate-limited receiver cooperation. We propose a coding scheme that tailors two versions of superposition coding with classical relaying protocols. Theproposed scheme unifies and recovers previous results for the unidirectional coop-eration, yet in simpler forms. Analytical and numerical results confirm the benefitsof cooperation and illuminate the ideas behind the coding strategy.The second problem generalizes the first one by allowing the existence of bothcrossover links in the channel. We propose a coding scheme for this channel byextending noisy network coding to encompass rate-splitting at the encoders. Theachievable rate region is shown to be the same as a region achieved by explicitbinning. As a corollary, we prove that noisy network coding achieves the capacityregion of the Gaussian channel within 1 bit, under strong interference. Our resultis among the first to show constant-gap optimality of noisy network coding for amultiple-unicast problem, and to demonstrate equivalence in terms of achievablerates of two different coding approaches for a noisy interference network.We follow up by introducing a dedicated relay into the interference channelwhich simultaneously helps both receivers. For this third problem, the interferencechannel with a relay, we propose new coding schemes based on layered codes for long- and short-message quantize-forward techniques. The short-message schemesshow improvements in the achievable rates compared to other known coding tech-niques, especially when the channel is asymmetric, while relaxing the excessive delayissue of the long-message scheme. The analysis also reveals the trade-off betweenachievable rates, encoding and decoding delays, and complexity.In the fourth problem, we propose a new model for cooperative communication,the interfering relay channels, which consists of two neighboring relay channelsinducing interference to each other. Each relay, by utilizing a finite-capacity andnoise-free link to its own receiver, helps the receiver decode the desired message.We characterize the exact and approximate capacity region and sum-capacity forvarious classes of channels. The established results generalize and unify severalknown results for the relay and interference channels.The methods and results shown in this thesis aim at providing insight intopotential techniques for cooperative interference management in real-world systems.
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| 7. |
- Do, Hieu, et al.
(författare)
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Gaussian Interfering Relay Channels
- 2013
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Ingår i: 2013 Asilomar Conference on Signals, Systems and Computers. - : IEEE Computer Society. - 9781479923908 ; , s. 1968-1972
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Konferensbidrag (refereegranskat)abstract
- We extend the primitive relay channel (PRC) in-troduced by Cover and Kim to a more general scenario wheretwo Gaussian PRC’s cause interference to each other. We show that extended hash-and-forward relaying with proper power allocation can achieve bounded gaps to the capacity region of the Gaussian channel in different regimes of channel parameters.
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| 8. |
- Do, Hieu, et al.
(författare)
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Layered quantize-forward for the two-way relay channel
- 2012
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Ingår i: Information Theory Proceedings (ISIT), 2012 IEEE International Symposium on. - : IEEE. - 9781467325790 ; , s. 423-427
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Konferensbidrag (refereegranskat)abstract
- This paper proposes two new coding schemes for the discretememoryless two-way relay channel. The main target is to show thebenefits of compress-forward without Wyner-Ziv binning and oflayered relaying in networks wherein a relay is to help multipledestinations, that may have unequal channel quality and/or haveaccess to different side information. Numerical results for aGaussian channel show that the new coding schemes outperformvariants of compress-forward relaying and offer a good trade-offbetween achievable rates and complexity and decoding delay. The ideacan also be applied to other relay networks.
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| 9. |
- Do, Hieu, et al.
(författare)
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Linear Beamforming and Superposition Coding with Common Information for the Gaussian MIMO Broadcast Channel
- 2009
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Ingår i: IEEE Transactions on Communications. - IEEE. - 0090-6778 .- 1558-0857. ; 57:8, s. 2484-2494
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Tidskriftsartikel (refereegranskat)abstract
- A Gaussian multiple-input multiple-output broadcast channel (MIMO GBC) is considered. Throughout the paper it is assumed that 1) input signals are Gaussian and 2) perfect channel state information is available at the transmitter and at the receivers. By considering each data stream as a single user, the uplink-downlink signal-to-interference-plus-noise (SINR) duality is generalized to the MIMO case with general cross-talk matrix. The duality is subsequently applied to finding the solution for the SINR-balancing problem. The result serves as a tool for characterizing achievable rate regions of different coding strategies. Next, we investigate a superposition coding scheme proposed by Cover-van der Meulen-Hajek and Pursley (nicknamed CMHP [1]), where there is a common message to both users. We consider a MIMO broadcast channel with two users, each user has two antennas and the transmitter has four antennas. Assuming one common stream is sent by CMHP coding and successive decoding, a lower bound to the CMHP rate region is found. Behaviors of the CMHP rate region and sumrate are analyzed. We find the sumrate gaps between DPC, CMHP, and MMSE at high SNR for general 2-user multiple-input single-output (MISO) Gaussian broadcast channel. The result suggests when CMHP is beneficial for sumrate.
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| 10. |
- Do, Hieu, et al.
(författare)
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Noisy network coding approach to the interference channel with receiver cooperation
- 2011
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Ingår i: 49th Annual Allerton Conference on Communication, Control, and Computing, 2011.. - 9781457718168 ; , s. 839-846
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Konferensbidrag (refereegranskat)abstract
- This work proposes a new coding scheme for thediscrete memoryless two-user interference channel whose receivers can cooperate to decode their desired messages. Thecoding scheme is built upon Han-Kobayashi rate splitting andsuperposition coding at the transmitters, noisy network coding,and non-unique joint decoding at the receivers. As a case studythe general achievable region leads to an inner bound for theGaussian interference channel whose receivers cooperate throughrate-limited orthogonal channels. It is shown that this innerbound is equivalent to the one-round quantize-bin-and-forwardinner bound established by Wang and Tse, thereby showing thatnoisy network coding achieves within 1 bit/s/Hz to the capacityregion when the interference is strong, and achieves within 1 bit/s/Hz to the capacity region of the Gaussian compound multipleaccess channel with conferencing decoders regardless of channelparameters.
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