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Diversity techniques are very effective tools to increase signal reception quality in Rayleigh fading channels. A novel space-time block coding method for cooperative relay networks is proposed which guarantees full diversity for any number of mobile relays with minimal delay, provided that few bits of feedback from the destination to the source and the relays are available. As in the case of orthogonal...
Signal Space Diversity (SSD) has been lately adopted into the second generation of the terrestrial digital video broadcasting standard DVB-T2. In this paper, a bit-interleaved coded modulation receiver for the DVB-T2 standard is detailed. An LDPC decoder based on a vertical layered schedule is the main novelty of this work. It enables an efficient exchange of extrinsic information between the rotated...
In this paper, a simple cooperative diversity scheme in M + 2 relay network with low-density parity-check (LDPC) codes is proposed. By allocating random interleavers to each relay node, the interleaved sequences provide M copies of received vector to achieve the cooperative diversity. An efficiently iterative coding algorithm is proposed with low complexity. The complexity involved grows linearly...
In this paper, we consider a cooperative relaying based cognitive radio (CR) networks in which the primary receivers are protected by peak interference power constraint. In such scenario, finding the transmission opportunity with a target data rate by maintaining the interference power constraint is the prime goal of the system. We show that cooperative relaying techniques can significantly reduce...
This paper provides the practical design of the transmit diversity technique with a nested coding technique and evaluates its performance via computer simulations. Similar to network coding techniques, the nested transmit diversity combines the transmit data with XOR operation. As a characteristic of the proposed transmit diversity, it can obtain diversity gain without some extra resources (e.g.,...
In this paper, we propose a novel protocol for cooperative diversity based on decode-and-forward (DF) with iterative detection and decoding (IDD) receiver. Closed-form expression of outage probability is derived under quasi-static fading channels. Numerical results show that the proposed scheme achieves higher diversity order than traditional DF scheme without additional transmitter power.
Cooperative communication has been recently proposed as a way to improve the performance of wireless communication. However, due to the half duplex constraint, most of the relay networks face a fundamental challenge in terms of multiplexing loss. In this paper, we present an adaptive cooperation via relay selection (ACRS) protocol that improves spectral efficiency. This protocol lets the source transmit...
Lattice reduction algorithms, such as the LLL algorithm, have been proposed as preprocessing tools in order to enhance the performance of suboptimal receivers in MIMO communications. In this paper we introduce a new kind of lattice reduction-aided decoding technique, called augmented lattice reduction, which recovers the transmitted vector directly from the change of basis matrix, and therefore doesn't...
The performance of Selection cooperation in the presence of a malicious relay is analyzed. The malicious relay introduces a new form of Denial of Service (DoS) attack at the physical layer, inhibiting source-destination communication from reaping the diversity and SNR gains produced through cooperation in the network. In this form of DOS attack, the relay does not alter the source information while...
Cooperative diversity is an attractive way to combat fading in wireless networks,. Conventionally, the outage probability, which measures robustness of the transmission to fading in cooperative communication, is deduced on the condition that the signal-to-noise ratio (SNR) is very high. However, the result is only an approximation. In this paper, proposed a new way to deduce the accurate outage probability...
In this paper, we consider an OFDM-based cooperative diversity system where a source communicates with a destination with the help of a relay in Amplify-and-Forward relaying or Decode-and-Forward relaying. First, we propose a scheme to selecting the "best" relay to assist the transmission. And then, we present two power allocation schemes to minimize system outage probability, based on statistical...
Combining coding, modulation, transmit and receive diversity, and validly increases the anti-noise performance in fading channels, OSTBC (orthogonal space-time block codes) is a new channel coding technology accompanying with the extensive application of wireless communication. Based on typical channel model of the OSTBC in MIMO (multiple-in, multiple-out) wireless communication channels, a general...
Based on the requirements of LTE-Advanced standardization, this paper provides an 8-Tx diversity scheme for LTE-Advanced downlink. The proposed scheme considers the complexity, compatibility, performance and etc. together. What's more, this paper gives the simulation results of the proposed scheme and shows the feasibility of the scheme.
In this contribution, we propose a novel Distributed Source-coding, Channel-coding and Modulation (DSCM) scheme for cooperative communications. The proposed DSCM scheme is designed for ensuring the decoding convergence of its constituent component codes, namely, the Variable Length Code (VLC) and two Coded Modulation (CM) schemes. The source node encodes the source symbols with the aid of a serially-concatenated...
Multiple-input multiple-output (MIMO) single carrier frequency division multiple access (SC-FDMA), which combines the advantage of spatial and frequency diversities with frequency domain equalizers (FDE), has drawn great attention recently. Among all possible detection techniques, maximum-likelihood detection (MLD) is optimal, but its exponentially computational complexity precludes its use in practical...
We propose a data precoded relay-assisted scheme, for a system cooperating with 2 relays. We assume that all the terminals are equipped with a single antenna. The use of relays is of significant interest to allow radio access in situations where a direct path is not available. However because of the half duplex constraint at the relays, transmission of a data rate equivalent to that of a modulation...
In, the authors have proposed an analysis on the problem of space-time coding for a synchronized wireless relay networks employing AF (Amplify-and-Forward) protocol which proposes LD (linear dispersion coding) by using linear transformation. In this paper, we extend it to a asynchronous wireless networks and to reduce more processing burden on the relay nodes by allocating interleavers at each relay...
In this paper, we propose an opportunistic relaying with multiple decode-and-forward (DF) relay nodes based on interference cancelation (IC). The relay that succeeds decoding data in the former phase performs IC to decode another data in the current phase without suffering from interference caused by the selected best relay that forwards the data of the former phase. It is shown that the proposed...
In this paper, an incremental redundancy based cooperative coding scheme for wireless networks is proposed. User cooperation is an effective way of mitigating fading where one user cooperates with another user in transmitting its information, thereby providing spatial diversity. Wireless transmissions are broadcast by nature and this provides a new dimension to the system in terms of an implicit feedback...
In this paper, we propose a novel multiuser cooperative communication scheme using random network coding for uplink wireless transmissions. The participating users transmit a linear combination of their new data packet and the packets successfully decoded due to preceding transmissions by other users, thus sending the new information as well as relaying the information for other users at the same...
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