The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We propose a rateless coded protocol for a half-duplex wireless relay channel where all links experience independent quasi-static Rayleigh fading and the instantaneous channel realizations are unavailable at the transmitters. We assume that the network does not have a stringent delay constraint-thus the source and/or the relay continue transmitting until the destination acknowledges successful decoding...
In this paper, we investigate an incremental opportunistic relaying scheme where the selected relay chooses to cooperate only if the source-destination channel is of an unacceptable quality. In our study, we consider regenerative relaying in which the decision to cooperate is based on a signal-to-noise ratio (SNR) threshold and takes into account the effect of the possible erroneously detected and...
In this paper, an efficient Decode-and-Forward (DF) relay selection scheme for interference-limited relaying networks is considered. In contrast to previously reported works, we consider multiple interferences which make the conventional relay selection schemes not suitable for interference-limited networks and propose a new relay selection scheme for DF protocol with multiple interferences. Approximate...
In this paper, we investigate the outage performance of decode-and-forward (DF) based opportunistic cooperative communications with channel estimation errors at the receivers under Rayleigh fading channels, in which the effect of the direct link has been explicitly evaluated. To be specific, the exact expression of outage probability has been derived for arbitrary values of signal-to-noise ratio (SNR)...
Selective decode and forward (SDF) based cooperative relaying protocol can provide full diversity. But SDF protocol requires bandwidth consuming cyclic redundancy check (CRC) bits to prevent error propagation from the relay. Link adaptive regenerative relaying (LAR) scheme avoids the need for CRC bits to reduce the error propagation from relay and can provide full diversity. But in the conventional...
This paper proposes a novel interference cancellation algorithm for the two-path succussive relay system using network coding. The two-path succussive relay scheme was proposed recently to achieve full date rate transmission with half-duplex relays. Due to the simultaneous data transmission at the relay and source nodes, the two-path relay suffers from the so-called inter-relay interference (IRI)...
MCN-MR (Multi-hop Cellular Network - Mobile Relay) has been proposed as a promising technology for future Beyond 3G and 4G systems due to its foreseen capacity to increase transmission rates and provide homogeneous quality of service levels in the service area. To this aim, mobile nodes are required to cooperate in the relaying of information of other nodes. As a result, selfish nodes refusing to...
Barrage relay networks (BRNs) are mobile ad hoc networks designed from the ground up to meet the demands of tactical edge communications. The fundamental building block of BRNs is not a point-to-point wireless link, but rather a rapid and robust broadcast mechanism that employs an autonomous cooperative communications scheme. Following a summary of basic BRN concepts, this paper demonstrates how the...
The paper proposes a network coded cooperation protocol for the uplink transmission of relay assisted cellular networks characterized by non-ideal source - relay links. The proposed protocol employs Reed Solomon codes as network codes in order to improve the Block Error Rate (BLER) and Bit Error Rate (BER) performance over the slow varying fading channels. The paper presents also an algorithm for...
A base station (BS) transmits (Tx) and receives (Rx) signals to and from multiple mobile users (MU) through a two-way amplify and forward (AF) relay station (RS) using a two-phase protocol. The BS and the RS are both equipped with multiple antennas. In the first phase (time or frequency), the BS and all MU transmit their signals to the RS. In the second phase, the relay transmits towards the BS and...
In this paper, we propose a double space-time transmit diversity (DSTTD)-based two-path relay system with power allocation and link combining methods. The two-path relaying protocol can restore spectral efficiency decreased due to the half-duplexing at the relay nodes and the DSTTD method can appropriately achieve the diversity gain from the two paths. To circumvent severe performance degradation...
This paper presents a new cooperative ARQ with a distributed relay selection that exploits overhearing of inter-relay channels to achieve higher diversity during retransmission. The relays employ decode and forward (DF) to establish the link between the source and the destination. Upon reception from the source, the number of relays available to contend for transmission depends on the conditions of...
A two-way relay channel with independent parallel Gaussian channels between the relay and the two terminals is considered. Focusing on the decode-and-forward protocol, the second phase of the communication, in which the relay broadcasts the two messages to their respective receivers, is studied. Precisely, the problem of computing the power allocation among the parallel channels that maximizes the...
We study the fundamental rate-interference trade-off between full-duplex and half-duplex transmission modes in a two-hop infrastructure-based decode-and-forward relay link. First, we derive closed-form expressions for average end-to-end capacities. Then, we show that it may be better to tolerate some loop interference in the full-duplex mode than to halve the end-to-end symbol rate by allocating two...
In downlink relay systems, the conventional straightforward relaying scheme named decode-and-forward (DF) protocol is used at relay station (RS) to decode the data received from base station (BS) and forward the decoded data to the mobile station (MS) to improve the spatial diversity gain. However, conventional DF mode is spectral inefficient and not capacity optimal since the wireless channels in...
During the last few years, several authors have studied the performance of many different types of channel codes for cooperative communication systems. Some of these codes include Low Density Parity Check (LDPC), Turbo and convolutional codes. Published results show that these codes effectively improve both the data rate and system performance in cooperative schemes such as the decode and forward...
Relaying is generally considered as a method to ensure capacity improvement and coverage extension in cellular systems. The additional communication traffic between a mobile station and a relay intermediately inserted into a link between RUE and BS requires additional considerations on HARQ protocol. In this paper, we propose a method to jointly and dynamically balance the maximum number of transmissions...
Cooperative communication offers a way to obtain spatial diversity in a wireless network without increasing hardware demands. The different cooperation protocols proposed in the literature are often studied under the assumption that all channel state information is available at the destination. In a practical scenario, channel estimates need to be derived from the broadcasted signals. In this paper,...
In this paper, we evaluate the delay experienced by Poisson arriving packets for Cooperative truncated HARQ with opportunistic relaying in the presence of a noisy feedback channel. We derive the theoretical expressions of the expected waiting time and the packet's sojourn time in the queue of truncated opportunistic cooperativeARQ and Hybrid ARQ I, with and without Packet Combining (PC), and Hybrid...
In this paper we present a novel Hybrid Automatic Repeat reQuest (HARQ) scheme for cooperative communication systems, called Coded Partial Retransmission (CPR). The method is based on the retransmission of only a fraction of the original codeword by the cooperating nodes, applying an appropriate power allocation. Numerical results using LDPC codes and Type-I HARQ with Chase Combining show that CPR...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.