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This paper evaluates the bit-error rate and spectral efficiency performance provided by the convolutional coded Quadrature Amplitude Modulation (QAM) configurations whose global rates are modified mainly by changing the numbers of code and non-coded bits mapped on a QAM symbol. The Bit Error Rate (BER) performance provided are compared to the ones of the convolutional coded modulations which map only...
This paper analyzes the spectral efficiency, probability of a lost block and average delay performances of the generic Repetition Redundancy (RR) and Incremental Redundancy (IR) truncated Hybrid-Automat Repeat reQuest (H-ARQ) algorithms on block-faded Rayleigh channels. The analysis presents the derivation of the three performance metrics' expressions, using an intermediate performance metric called...
The increased demand of low-latency and spectrally efficient wireless transmissions requires accurate performance prediction mechanisms. A widely used performance prediction method for coded multicarrier transmissions applying iteratively decoded error correction codes is based on the employment of the mean mutual information of the coded bit. A precise knowledge at the transmitter site of the log...
This paper analyzes the block error rate (BLER) performance provided by a virtual MIMO scheme which implements a modified Alamouti Space-Frequency Block Code (SFBC) encoding-decoding algorithm using two fixed Decode &Forward relays that perform selective relaying, and single-antenna devices. It also analyzes the performance of the classical relay-based distributed Alamouti scheme with single-antenna...
This paper proposes a link adaptation algorithm for cooperative transmissions in the down-link connection of an OFDMA-based wireless system. The algorithm aims at maximizing the spectral efficiency of a relay-aided communication link, while satisfying the block error rate constraints at both the relay and the destination nodes. The optimal solution would be to perform an exhaustive search over a high-dimensional...
Wireless sensor networks employed in industrial and other special applications have strict requirements concerning the transmission reliability, delays and energy efficiency. This paper proposes a scalable approach for increasing transmission reliability in wireless sensor networks, based on a cooperative scheme that uses Reed–Solomon codes as network code. The block error rate of the proposed coded...
This paper analyzes the block error rate and spectral efficiency performances of an Enhanced Two-Way Relay Channel (2wRCE) scheme over block Rayleigh-faded channels in a generic cellular environment. It presents the derivation of the theoretical expressions of the Block Error Rate (BLER) and spectral efficiency provided by the studied scheme, using an approximate method to compute the BLER ensured...
The increased demand of spectrally efficient wireless transmissions requires accurate performance prediction mechanisms. A promising prediction method for OFDM transmission using convolutional turbo codes is based on the mean mutual information per coded bits. This paper aims to study the accuracy provided by the theoretical method used to compute the mean mutual information per coded bit presented...
To provide a high system performance, the link adaptation algorithms need an accurate method to predict the Block Error Rate (BLER) performance of a transmission on a given realization of the wireless multipath propagation channel. A promising BLER prediction technique is based on mean mutual information of the received bits (MI). The main objective of this paper is to compare the MI values obtained...
We propose a method for the design and evaluation of distributed iterative algorithms for receiver cooperation in interference-limited wireless systems. Our approach views the processing within and collaboration between receivers as the solution to an inference problem in the probabilistic model of the whole system. The probabilistic model is formulated to explicitly incorporate the receivers' ability...
We propose a link adaptation algorithm for cooperative transmissions in an OFDMA-based wireless system. The algorithm aims at maximizing the spectral efficiency of a relay-aided communication link, while satisfying the block error rate constraints at both the relay and the destination nodes. The optimal solution would be to perform an exhaustive search over a high-dimensional space determined by all...
One of the most appropriate techniques to increase the reliability of wireless sensor networks used in industrial environments are the network coding techniques. This paper proposes an effective, yet simple and scalable approach based on a relay-assisted cooperative scheme that uses Reed Solomon codes as network codes for such wireless sensor networks with cluster-tree topologies. The global Block...
The present paper explores the behavior of a swarm network that relies on random linear codes to improve the content distribution to all the clients. The swarm implementation is simplified with respect to other known implementations (e.g. BitTorrent) by discarding the coordination mechanism between the peers, relying only on the linear encoding to still provide an efficient content dissemination inside...
The use of cooperative channel coding is shown to increase the performance of relay-assisted wireless transmissions. This paper analyzes the spectral efficiencies provided by two cooperative channel coding algorithms and by the non-cooperative transmission, while ensuring a coded-block error rate (BLER) smaller than a target value BLERt. The results obtained in the study are used to propose an adaptive...
Over the Internet, bit errors within the data packets translate into packet losses at the higher layers of the OSI model, yielding a packet erasure channel. Modern erasure correcting codes promise to offer a very simple and efficient solution to data transfers over these channels, opening up also other interesting applications. Amongst them one can enumerate reliable large scale content distribution,...
Next generation wireless networks are likely to include cooperative relaying in their design. The performance of certain cooperation schemes in realistic scenarios should be evaluated by system level simulations (SLS). Moreover, the link adaptation (LA) and radio resource management become more complex, since cooperation schemes involve transmissions on more than one link and joint processing at the...
This paper presents a protocol designed as an alternative to classical TCP for channels which experience high loss-rates. The protocol is simplified with respect to TCP by eliminating the need of retransmissions and the associated buffers. This is achieved by applying a rateless erasure correcting code to the data that is going to be transferred. A modified version of the TCP congestion control algorithms...
The employment of relay-nodes (RN) to assist the base station-user terminal (BS-UT) transmissions in wireless systems could lead to significantly increased performance when compared to the direct BS-UT transmissions, provided that a PER smaller than a target-PER should be ensured. Nevertheless, the performance of the cooperative BS-RN-UT link is depending on the coded-cooperation algorithm employed...
This paper analyzes the performance provided on the uplink connection by a cooperative cluster, composed of user terminals and relays, which employ a XOR-based network coding algorithm. The paper presents the construction of the graphs that describe the operation of the algorithm within the selected topology. It then provides a theoretical analysis of the performance ensured by this algorithm in terms...
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