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Dual-hop transmission systems employing fixed-gain amplify-and-forward (AF) relaying have been studied recently over Nakagami fading channels. These analyses, however, either have imposed certain constraints on the fading parameters or have not been totally accurate when evaluating the diversity order of the systems. In this letter, we will develop a methodology for evaluating the diversity order...
In opportunistic relaying, exchanging information is essential to select the best relay. However, too many information-exchanges may rather impair the system performance due to causing congestion in feedback link as well as increasing overhead. In this paper, we investigate the effects of feedback strategies on performances of opportunistic amplify-and-forward (AF) relaying. We consider four feedback...
This paper investigates a spectrum-efficient cooperative diversity method based on butterfly network, which endows that a relay can encode the data received from two users and then forward the coded data to destination. Under the assumption that the relay can reliably overhear the data from two users, we discuss the outage probability and diversity gain. Moreover, the outage probability and diversity...
Observation of the mobile satellite system industry shows a significant growth in the need for more demanding services and higher rates these last years; as an example, recent success of hybrid broadcasting system (XM, Sirius) and DVB-SH arrival are meeting commercial users expectations in terms of high rates mobile communications. In this context, the use of diversity and MIMO schemes (cyclic delay...
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...
The antenna diversity based on log-likelihood ratio (LLR) is a new technology which is better than that based on signal-to-noise ratio (SNR) in performance. In this paper, we derive the expressions of transmit antenna selection schemes based on SLLR and BLLR over MIMO Nakagami channel. The average bit-error rate (BER) performance of M-ary on the correlated fading channel simulated by the Kronecker...
To achieve full transmission rate for complex signals, quasi orthogonal space-time block coding has been proposed while sacrificing the full diversity. However, due to complex channel condition its performance needs to be improved via antenna selection (AS). Moreover, to achieve utterly orthogonal performance against OSTBC, quasi-orthogonal STBC can still be improved combining pre-coding and antenna...
In this paper, we study the diversity-multiplexing tradeoff (DMT) of a novel decode or quantize and forward (DoQF) protocol for the half duplex single relay channel. It is well-known that the so-called dynamic decode and forward (DDF) achieves the multiple-input-single-output (MISO) bound in the range of multiplexing gains r < 0.5. But to the best of our knowledge, no practical coding scheme allows...
Cooperative diversity systems rely on using relay nodes to relay copier of transmitted information to the destination such that each copy experiences different channel fading, hence increasing the diversity of the system. In this letter, we proposed a novel distributed cooperative beamforming scheme for decode-and-forward relay networks without channel state information (CSI) feedback. We further...
The paper introduces a new concept of groupwise generalized selection combining (GGSC), denoted by GGSC(n, m, L) , in which there are n groups of generalized selection combining GSC(m, L) where the largest m (in SNR) elements are selected from L independent elements. The paper proves that GGSC(n, m, L) has the same diversity order (DO) as that of MRC with nL elements, denoted by MRC(nL) and GSC(nm,...
In wireless networks, the conventional routing approach is to pre-select the next-hop receiver for a packet based on knowledge of the network topology. However, when the nodes experience fading that changes on the order of the packet duration, a conventional routing approach will often offer poor performance because the pre-selected receiver may not be able to recover the packet because of fading...
Relay-based access technology is expected to be a major access technology in 4G/IMT-advanced system. In this paper, the performance evaluation is given for the cooperative relay network, with considering a more efficient cooperative decode-and-forward(DF) relay channel which provides higher data rate than traditional one. Furthermore, the multi-user diversity is analyzed in the cooperative relay-based...
In this paper, asymptotic symbol error rates (ASERs), of dominant eigenmode transmission (DET) for MIMO (multiple inputs and multiple outputs) diversity gain with small diversity order (the product of the number of Tx antennas and the number of Rx antennas) and Tx/selection (SC)-Rx/MRC with an arbitrary diversity order over a Rayleigh fading channel are derived. The SNR gaps among DET, Tx/SC-Rx/MRC...
This work presents a novel adaptive cooperation scheme that takes both the channel state information and residual energy information into account to prolong the network lifetime while meeting the transmission rate requirement of destination. In order to achieve this aim, we will select the relay with the best instantaneous weighted channel conditions by attributing a weight coefficient to each relay...
In this work, we study the performance of rate-compatible punctured convolutional (RCPC) coded cooperation system. Theoretical bit error probability is deduced over slow Rayleigh fading channel based on the characteristics of RCPC codes and coded cooperation. The coded cooperative system obtains two inherent benefits, such as achieving the spatial diversity offered by the relay channel and also the...
In this paper, we present a new outage probability analysis of a cooperative system with single antenna terminal. We first introduce the cooperation protocol of the presented scheme. Then, in the destination node, maximal ratio receiver combining (MRRC) and the maximum likelihood (ML) detection algorithm are applied to decode the received signal with the utilization of the signal received from the...
An accurate model for analyzing the performance of wireless land mobile satellite (LMS) communication systems is the shadowed-Rice (SR) fading model. In this paper, new simple expressions for the probability density function (PDF) and the cumulative distribution function (CDF) of the sum of possibly correlated non identically distributed squared SR random variables are derived. To this end, a novel...
User cooperation is employed to explore the inherent distributed spatial diversity priority of wireless network. Nodes based rather than linked based protocol is employed and the broadcast nature of radio network is considered by user cooperation. However cooperative partner selection might be difficult especially for nomadic cooperative networks as it requires partner's additional power consumption...
Cooperative diversity has been recently proposed as a way to form virtual antenna arrays that provide dramatic gains in slow fading wireless environments. In a multiple-relay network, the opportunistic relay selection scheme has been shown to outperform any other strategy that involves the conventional all-participate scheme. The opportunistic relay selection scheme generally supposes the existence...
In this paper, making use of the relaying concept, which enables single-antenna devices to benefit from spatial diversity, a statistical analysis of dual-hop cooperative links using semi-blind (fixed gain) relays and partial relay selection, is provided. The selection scheme considers that the source monitors the connectivity among the nodes (relays) of the first hop only; an interesting assumption...
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