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We study the transmission over a cloud radio access network in which multiple relays are connected to a central processor (CP) via error-free finite-capacity links. We develop a lattice-based coding scheme in which each relay node computes a linear combination of the users' messages, in the spirit of standard compute-and-forward (CoF). However, rather than forwarding the computed equation to the CP...
This paper proposes a simple hybrid decode- compress- and-forward and compress-and-forward (DCF&CF) relay scheme for the coordinated multipoint (CoMP) uplink transmission. In particular, we consider a scenario that two mobile users (MUs) transmit signal to two access points (APs), which are linked to the central unit (CU) via lossless capacity-limited fronthaul. To characterize the achievable...
In this work, we propose a new technique of spatially-coupled low-density parity-check coding within a threshold-based lossy forwarding protocol for a multiple access relaying system. Here, block Rayleigh fading is assumed for all transmission links and error-free decoding at the relay is not required. Two schemes are presented in which the relay computes log-likelihood ratios (LLRs) of the network-coded...
This paper presents a prototype implementation and experimental performance evaluation of compress- and-forward (CF) relaying using software-defined radios. Under QPSK transmissions from all nodes, the relay demodulates the received signal before applying distributed joint source-channel coding (DJSCC) implemented with the help of an off-the- shelf convolutional code. The destination employs two stages...
In this paper, the secrecy of a cooperative system consisting of a single source, relay, destination and eavesdropper is analyzed. The threshold-selection decode-and-forward relay is considered, where the relay can correctly decode and forward only if it satisfies a threshold signal-to-noise ratio (SNR). Both destination and eavesdropper take advantage of the direct and relayed transmissions through...
This paper investigates a new methodology for soft information forwarding (SIF) based on a novel technique known as soft angular modulation (SAM). In this new relay scheme, the soft symbols are embedded into phases at the relay. This is more advantageous as we refrain to forward real values (under bandwidth constraints) via wireless channels. This makes the proposed scheme practically feasible. The...
This paper investigates a wireless-powered cooperative communication network consisting of a source, a destination and a multi-antenna decode-and-forward relay. We consider the relay as a wireless-powered node that has no external power supply; but it is equipped with an energy harvesting (EH) unit and a rechargeable battery such that it can harvest and accumulate energy from radio-frequency signals...
The emergence of Internet-of-Thing (IoT) has driven tremendous growth of number of connected devices such that in the near future everything is connected to the networks forming super-dense networks. To cope with this challenge, this paper investigates networks with multiple relays serving massive number of devices (users), termed as multiway multirelay (MWMR) networks. Coded random access is adopted...
Selection cooperation is an effective solution for cooperative communications and the automatic repeat request (ARQ) protocol can provide additional diversity gain for wireless networks. In this work, considering a large network where direct transmissions only exist in the neighbors of each node, we investigate an improved diffusion selection cooperation protocol integrated with ARQ, and taking into...
Network coding (NC) is a promising approach to efficiently enhance the robustness and recovery capacity in the Underwater acoustic sensor network (UWASN). However, the undesired transmission redundancy and additional resource limit the further development for NC with applications to the UWASN. Based on the analysis of intermediate nodes, a new approach called encoding anticipation mechanism for network...
In order to reduce the outage probability of cooperative communication, a hybrid forwarding HARQ scheme in wireless network is proposed. In this scheme, if the relay decoding unsuccessfully until the last time, the Amplify-and-Forward protocol will be used to retransmit. Otherwise, the code cooperation will be used. Both of the Chase Combining and Incremental Redundancy combining is used in this scheme...
This paper deals with the problem of transceiver optimization for amplify-and-forward multiple-input multiple-output (MIMO) cooperative networks with multiple relays. We consider the case where precoding at the source, forwarding at the relays, and decoding at the destination are all carried out by means of widely-linear (WL) structures. On the basis of the minimum-mean-square-error criterion with...
In this paper, we dedicate to fighting against the multiple carrier frequency offsets (MCFOs) in two-relay decode-and-forward (DF) cooperative networks. A full-rate code named frequency reversal Alamouti code (FRAC) is designed for two-relay cooperative orthogonal frequency-division multiplexing (OFDM) networks. Reversal makes the equivalent channel matrix between the relays and the destination complex...
Physical layer network coding (PNC) with channel coding is a strategy that applies error correction at the relay nodes of a relay system to improve data communication reliability of the whole relay system. So far, channel coded PNC schemes have been studied for two-way relay systems, but have not been systematically proposed for general multiple-way relay systems. In this paper, joint channel coding...
In this paper, we propose a hybrid time switching and power splitting spectrum sharing protocol for energy harvesting wireless sensor nodes. Specifically, we use an approach of simultaneous energy harvesting and spectrum access to alleviate the major concerns of wireless sensor nodes such as limited power and spectrum. In the developed framework, an energy constrained sensor node adopts a time switching...
In this paper a cognitive radio network is considered where a licensed primary user and an energy harvesting secondary (cognitive) user co-exist, and relaying protocols are proposed where the cognitive user acts as a relay for the primary signal in return for spectrum access. We analyze two relaying paradigms, namely, time-splitting cooperative spectrum sharing (TS-CSS) relaying and power sharing...
Successive relaying (SR) provides an effective transmission scheme to recover the multiplexing loss of the traditional cooperative networks. However, SR suffers from the inter-relay interference (IRI) problem, which results in transmission error and degrades the system throughput. In order to achieve full-diversity, interference cancellation (IC) is introduced to the reception at relay nodes. To completely...
Highly dense wireless networks is one of the most important solutions for spectrum shortage expected by 2020. Motivated by a generally assumption that direct links between users in HD-MWR networks are usually ignored, this paper proposes high-dense multiway relay (HD-MWR) networks exploiting available direct links as side information (SI) to serve even higher number of users or devices required for...
In this paper, we re-visit the relay broadcast channel with confidential messages (RBC-CM) by considering a compress-and-forward (CF) inner bound on the capacity-equivocation region of the RBC-CM. This CF inner bound is further explained via a degraded Gaussian example, and we show that in some particular cases, the CF strategy performs better than the decode-and-forward (DF) and noise-and-forward...
This paper presents a link quality model for a wireless communication system with distributed turbo coding and lossy forwarding. The model maps the signal-to-interference-plus-noise ratio (SINR) of packet copies received from different links to a mutual information parameter and, in a second stage, converts it to a block error rate. We present the design and foundation of the model and validate its...
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