Results 1  10
of
45
Computeandforward: Harnessing interference through structured codes
 IEEE TRANS. INF. THEORY
, 2009
"... ..."
Wireless Network Information Flow
, 710
"... Abstract — We present an achievable rate for general deterministic relay networks, with broadcasting at the transmitters and interference at the receivers. In particular we show that if the optimizing distribution for the informationtheoretic cutset bound is a product distribution, then we have a ..."
Abstract

Cited by 56 (15 self)
 Add to MetaCart
Abstract — We present an achievable rate for general deterministic relay networks, with broadcasting at the transmitters and interference at the receivers. In particular we show that if the optimizing distribution for the informationtheoretic cutset bound is a product distribution, then we have a complete characterization of the achievable rates for such networks. For linear deterministic finitefield models discussed in a companion paper [3], this is indeed the case, and we have a generalization of the celebrated maxflow mincut theorem for such a network. I.
Coding techniques for primitive relay channels
 in Proc. FortyFifth Annual Allerton Conf. Commun., Contr. Comput
, 2007
"... Abstract—We give a comprehensive discussion on coding techniques for the primitive relay channel, in which the channel input X is transmitted to the relay Y1 and the ultimate receiver Y over a channel p(y, y1x) and the relay can facilitate the communication between the transmitter and the receiver ..."
Abstract

Cited by 31 (2 self)
 Add to MetaCart
(Show Context)
Abstract—We give a comprehensive discussion on coding techniques for the primitive relay channel, in which the channel input X is transmitted to the relay Y1 and the ultimate receiver Y over a channel p(y, y1x) and the relay can facilitate the communication between the transmitter and the receiver by sending some information to the receiver over a separate noiseless link of capacity R0. In particular, we compare three known coding schemes, “decodeandforward, ” “compressandforward, ” and “hashandforward, ” clarify their limitations, and explore further extensions. Possible unification of these coding schemes is also discussed, as well as a few open problems reflecting major difficulties in proving optimality. I.
Gaussian Zinterference channel with a relay link: Achievable rate region and asymptotic sum capacity
 in Proc.Int.Symp. Inf. Theory and Its App
, 2008
"... Abstract — This paper studies the Gaussian Zinterference channel with a ratelimited digital relay link from one receiver to the other receiver. In a companion paper, we dealt with the Type I channel, where the relay link goes from the interferencefree receiver to the interfered receiver. It was s ..."
Abstract

Cited by 24 (5 self)
 Add to MetaCart
(Show Context)
Abstract — This paper studies the Gaussian Zinterference channel with a ratelimited digital relay link from one receiver to the other receiver. In a companion paper, we dealt with the Type I channel, where the relay link goes from the interferencefree receiver to the interfered receiver. It was shown that in the weak interference regime, each relay bit can improve the sum capacity by up to one bit asymptotically in the high signaltonoiseratio and interferencetonoiseratio limit. In this paper, we study the Type II channel where the relay link goes from the interfered receiver to the interferencefree receiver. The capacity region for such a channel is established in the strong interference regime; achievable rate regions are established in the moderately strong and weak interference regimes. In the weak interference regime, we show that in contrast to the Type I channel, the sum capacity improvement due to relaying for the Type II channel is upper bounded by at most half a bit, even as the relay link rate goes to infinity. I.
Capacity of a Class of Diamond Channels ∗
, 2008
"... We study a special class of diamond channels which was introduced by Schein in 2001. In this special class, each diamond channel consists of a transmitter, a noisy relay, a noiseless relay and a receiver. We prove the capacity of this class of diamond channels by providing an achievable scheme and a ..."
Abstract

Cited by 10 (3 self)
 Add to MetaCart
(Show Context)
We study a special class of diamond channels which was introduced by Schein in 2001. In this special class, each diamond channel consists of a transmitter, a noisy relay, a noiseless relay and a receiver. We prove the capacity of this class of diamond channels by providing an achievable scheme and a converse. The capacity we show is strictly smaller than the cutset bound. Our result also shows the optimality of a combination of decodeandforward (DAF) and compressandforward (CAF) at the noisy relay node. This is the first example where a combination of DAF and CAF is shown to be capacity achieving. Finally, we note that there exists a duality between this diamond channel coding problem and the KaspiBerger source coding problem.
On Codebook Information for Interference Relay Channels With OutofBand Relaying
"... Abstract—A standard assumption in network information theory is that all nodes are informed at all times of the operations carried out (e.g., of the codebooks used) by any other terminal in the network. In this paper, information theoretic limits are sought under the assumption that, instead, some n ..."
Abstract

Cited by 9 (0 self)
 Add to MetaCart
(Show Context)
Abstract—A standard assumption in network information theory is that all nodes are informed at all times of the operations carried out (e.g., of the codebooks used) by any other terminal in the network. In this paper, information theoretic limits are sought under the assumption that, instead, some nodes are not informed about the codebooks used by other terminals. Specifically, capacity results are derived for a relay channel in which the relay is oblivious to the codebook used by the source (oblivious relaying), and an interference relay channel with oblivious relaying and in which each destination is possibly unaware of the codebook used by the interfering source (interferenceoblivious decoding). Extensions are also discussed for a related scenario with standard codebookaware relaying but interferenceoblivious decoding. The class of channels under study is limited to outofband (or “primitive”) relaying: Relaytodestinations links use orthogonal resources with respect to the transmission from the source encoders. Conclusions are obtained under a rigorous definition of oblivious processing that is related to the idea of randomized encoding. The framework and results discussed in this paper suggest that imperfect codebook information can be included as a source of uncertainty in network design along with, e.g., imperfect channel and topology information. Index Terms—Codebook information, femtocells, interference channel, relay channel, robust coding.
A New Achievable Rate for the Gaussian Parallel Relay Channel
, 2008
"... Schein and Gallager introduced the Gaussian parallel relay channel in 2000. They proposed the AmplifyandForward (AF) and the DecodeandForward (DF) strategies for this channel. For a long time, the best known achievable rate for this channel was based on the AF and DF with time sharing (AFDF). R ..."
Abstract

Cited by 9 (0 self)
 Add to MetaCart
(Show Context)
Schein and Gallager introduced the Gaussian parallel relay channel in 2000. They proposed the AmplifyandForward (AF) and the DecodeandForward (DF) strategies for this channel. For a long time, the best known achievable rate for this channel was based on the AF and DF with time sharing (AFDF). Recently, a RematchandForward (RF) scheme for the scenario in which different amounts of bandwidth can be assigned to the first and second hops were proposed. In this paper, we propose a Combined AmplifyandDecode Forward (CADF) scheme for the Gaussian parallel relay channel. We prove that the CADF scheme always gives a better achievable rate compared to the RF scheme, when there is a bandwidth mismatch between the first hop and the second hop. Furthermore, for the equal bandwidth case (Schein’s setup), we show that the time sharing between the CADF and the DF schemes (CADFDF) leads to a better achievable rate compared to the time sharing between the RF and the DF schemes (RFDF) as well as the AFDF.
Beamforming design for multiuser twoway relaying: A unified approach via maxmin SINR [Online]. Available: http://arxiv.org/abs/1307.0052
"... Abstract—In this paper, we develop a unified framework for beamforming designs in nonregenerative multiuser twoway relaying (TWR). The core of our framework is the solution to the maxmin signaltointerferenceplusnoiseratio (SINR) problem for multiuser TWR. We solve this problem using a Dinkel ..."
Abstract

Cited by 6 (5 self)
 Add to MetaCart
(Show Context)
Abstract—In this paper, we develop a unified framework for beamforming designs in nonregenerative multiuser twoway relaying (TWR). The core of our framework is the solution to the maxmin signaltointerferenceplusnoiseratio (SINR) problem for multiuser TWR. We solve this problem using a Dinkelbachtype algorithm with nearoptimal performance and superlinear convergence. We show that, using the maxmin SINR solution as a corner stone, the beamforming designs under various important criteria, such as weighted sumrate maximization, weighted sum meansquareerror (MSE) minimization, and average biterrorrate (BER) or symbolerrorrate (SER) minimization, etc, can be reformulated into a monotonic program. A polyblock outer approximation algorithm is then used to find the desired solutions with guaranteed convergence and optimal performance (provided that the core maxmin SINR solver is optimal). Furthermore, the proposed unified approach can provide important insights for tackling the optimal beamforming designs in other emerging network models and settings. For instances, we extend the proposed framework to address the beamforming design in collaborative TWR and multipair MIMO TWR. Extensive numerical results are presented to demonstrate the merits of the proposed beamforming solutions. Index Terms—Beamforming, fractional program,monotonic optimization, semidefinite program, twoway relaying. I.
A New Upper Bound on the Capacity of a Class of Primitive Relay Channels
"... Abstract — We obtain a new upper bound on the capacity of a class of discrete memoryless relay channels. For this class of relay channels, the relay observes an i.i.d. sequence T, which is independent of the channel input X. The channel is described by a set of probability transition functions p(yx ..."
Abstract

Cited by 4 (0 self)
 Add to MetaCart
(Show Context)
Abstract — We obtain a new upper bound on the capacity of a class of discrete memoryless relay channels. For this class of relay channels, the relay observes an i.i.d. sequence T, which is independent of the channel input X. The channel is described by a set of probability transition functions p(yx, t) for all (x, t, y) ∈ X × T × Y. Furthermore, a noiseless link of finite capacity R0 exists from the relay to the receiver. Although the capacity for these channels is not known in general, the capacity of a subclass of these channels, namely when T = g(X, Y), for some deterministic function g, was obtained in [1] and it was shown to be equal to the cutset bound. Another instance where the capacity was obtained was in [2], where the channel output Y can be written as Y = X ⊕ Z, where ⊕ denotes modulom addition, Z is independent of X, X  = Y  = m, and T is some stochastic function of Z. The compressandforward (CAF) achievability scheme [3] was shown to be capacity achieving in both cases. Using our upper bound we recover the capacity results of [1] and [2]. We also obtain the capacity of a class of channels which does not fall into either of the classes studied in [1] and [2]. For this class of channels, CAF scheme is shown to be optimal but capacity is strictly less than the cutset bound for certain values of R0. We further illustrate the usefulness of our bound by evaluating it for a particular relay channel with binary multiplicative states and binary additive noise for which the channel is given as Y = T X + N. We show that our upper bound is strictly better than the cutset upper bound for certain values of R0 but it lies strictly above the rates yielded by the CAF achievability scheme. I.