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We consider a three-terminal Gaussian relay channel corrupted by a Gaussian interference. We assume that the interference is non-causally known to only some, i.e, not to all, the terminals. We examine two different scenarios: 1) both the source and the relay, but not the destination, know the interference and collaborate to cancel out its effect and 2) only the source knows the interference. The first...
In this work, a novel two-level rate superposition coding relaying (SC-relaying) strategy is investigated. In this SC-relaying strategy, the channel state feedback of relay-to-source is introduced under a long term power constraint at source. For the SC-relaying strategy, the source power SNR exponent constraints are first obtained. And then, by using the power SNR exponent constraints, the optimizing...
In this paper, closed-loop quasi-orthogonal space time block coding(QO-STBC) is exploited within a four relay node transmission scheme to achieve full-rate and increase the available diversity gain provided by earlier two relay approaches. The problem of imperfect synchronization between relay nodes is overcome by applying a parallel interference cancellation (PIC) detection scheme at the destination...
We characterize achievable rate regions of the butterfly network with noisy links and end-to-end error correction. We consider low-complexity relays, i.e., relays without the processing power to decode received signals. Decoding is done only at the destinations. Three decoding strategies are studied: independent, serial, and joint decoding.
We examine the extent to which Gaussian relay networks can be approximated by deterministic networks, and present two results, one negative and one positive. The gap between the capacities of a Gaussian relay network and a corresponding linear deterministic network can be unbounded. The key reasons are that the linear deterministic model fails to capture the phase of received signals, and there is...
A novel sum-rate outer bound for the Gaussian interference channel with a relay is presented. The outer bound is obtained by adapting the genie-aided approach developed for interference channels in. The cut-set bound for this channel is also derived and is shown to be much looser than the new bound. The new bound is also compared to an achievable rate region we introduced in previous work. We show...
For the multiple-access relay channel with relay-source feedback, we derive an outer bound on the capacity region CMARC. We also derive an achievable rate region RFB which is in general larger than the capacity region without feedback. The presence of the feedback enables the sources to understand each other's messages, which in turn allows the sources to cooperate to resolve the residual uncertainty...
This paper develops cooperative communication strategies based upon linear stochastic approximation algorithms for the Gaussian relay channel with several configurations of perfect and noisy feedback. In addition to being simple, the strategies can be shown to provide doubly exponential error decay in the case of perfect feedback and appealing tradeoffs between effective transmission rate and reliability...
In this paper we propose a partial network coding with cooperation (PNC-COOP) scheme that mitigates error propagation due to channel imperfections and achieves acceptable throughput in wireless ad hoc networks. It combines opportunistic network coding with decode-and-forward cooperative diversity. The proposed PNC-COOP is a decentralized strategy which provides substantial benefits when transmission...
Cooperative hybrid-ARQ (HARQ) protocols have been widely studied because they are more efficient than cooperative protocols without HARQ. In, the throughput of a cooperative HARQ protocol based on the decode-and-forward protocol (DF-HARQ) is obtained. In this paper, the maximum achievable throughput of the DF-HARQ protocol is obtained using the asymptotic outage probability when the maximum number...
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...
The capacity of the symbol-asynchronous single-relay channel is investigated. Symbol asynchronism implies that the codewords transmitted from the relay and the source do not coincide in time at the destination. Due to propagation or implementation effects (e.g. mis-synchronized clocks), symbol asynchronism occurs in many practical situations. In ad hoc scenarios, such as sensor networks, achieving...
We present the e-outage capacity of incremental relaying at low signal-to-noise ratios (SNR) in a wireless cooperative network with slow Rayleigh fading channels. The relay performs decode-and-forward and repetition coding is employed in the network, which is optimal in the low SNR regime. We derive an expression on the optimal relay location that maximizes the e-outage capacity. It is shown that...
Abstract-We consider an asymmetrical two-way relay channel (TWRC) which consists of one relay node and two user nodes in this paper. In TWRCs, we can efficiently use the channel by using the network coding at the relay with the exclusive OR (XOR) operation. However, due to the nature of the XOR, the rate from the relay to a user node should be the same as the rate from the relay to the other user...
We consider a three-way relay channel using a network coding in this paper. We propose a network coding scheme for the three-way relay channels and present a Latin square-like condition for the three-way network code. We also propose several schemes to design a new three-way network code by using the cell swapping and applied the methods to obtain a better network code to obtain a fair symbol error...
User cooperation enables single antenna terminals to benefit from spatial diversity by partnering with other users to create a virtual transmit antenna array. A promising form of cooperation is called coded cooperation which integrates cooperation with channel coding, showing great performance gains. In this paper, we examine the performance of coded cooperation scheme in fixed relay system, where...
We study two-way communications over a three-node Gaussian relay channel. Several practical relaying strategies are considered, including bitwise XOR-based decode-and-forward (DF), superposition-based DF, and amplify-and-forward (AF). For each considered two-way relay scheme, we show that its achievable rate pair is governed by a set of linear inequalities. As a result, we obtain explicit, analytical...
A relay scheme combining network coding with channel coding is proposed for multiple-access relay channel. Via a newly designed network low density parity check code, this scheme permits the relay node to jointly encode the data information from two source nodes. To predict the system performance, a newly generalized Gaussian approximation algorithm is derived, based on which an optimization algorithm...
In the IEEE 802.16j multi-hop relay (MR) network, the design of an effective path selection scheme is an important issue for throughput gain and overhead reduction. This paper proposes a new metric, called SEL, to evaluate the possible relay paths and thereby determine the appropriate one among these paths. SEL mainly considers both link spectral efficiency and link load, and based on SEL, a comprising...
In this paper, we propose two efficient schemes, named the CID-translated forwarding scheme (CTFS) and the enhanced CID-translated forwarding scheme (E-CTFS), to forward the broadcast data in the IEEE 802.16j multi-hop relay (MR) network. Motivated by the effective CID translation, CTFS and E-CTFS primarily relay the broadcast message without appending the relay MAC header. Moreover, E-CTFS classifies...
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