We propose LDPC code designs for the half-duplex relay channel. Our designs are derived from the information theoretic random coding scheme for decode-and-forward relaying. An important advantage of our scheme is that it is built entirely of single-user codes. The optimization of relay LDPC code profiles presents unique challenges, which are met by modifying the density evolution algorithm by i...

—Two-way amplify-and-forward (AF) relaying networks have been widely studied because of its simplicity and high spectral efficiency. In this paper, we investigate the relay selection problem and the diversity-multiplexing tradeoff (DMT) for two-way AF relaying systems over independent flat Rayleigh fading channels. We first derive the closed-form expression of the minimum total transmit power ...

In this paper, we propose high-rate space-time coding for cooperative wireless networks to reduce the overall delay incurred in relaying signals to multiple receivers. The relay structure is optimized in order to achieve maximum SNR at the receiver nodes. The proposed scheme provides a significant reduction in the delay required for the relaying and transmission of the signals to the multiple r...

Evaluating the performance of a cooperative relaying protocol requires an implementation for simulators and/or software-defined radios (SDRs) with an appropriate model for error detection, combining, and Medium Access Control (MAC) automaton. Such implementations are essential for meaningful evaluation of practical systems since any protocol introduces overhead that constrains the theoretical p...

The Mafia fraud consists in an adversary transparently relaying the physical layer signal during an authentication process between a verifier and a remote legitimate prover. This attack is a major concern for certain RFID systems, especially for payment related applications. Previously proposed protocols that thwart the Mafia fraud treat relaying and nonrelaying types of attacks equally: whethe...

Relay-assisted transmission schemes for wireless networks are continuing to grow because of their potential of providing the benefits of space diversity. This paper applies hybrid relaying protocols to coded cooperation which is a combined scheme of user cooperation and channel codes. The hybrid relaying protocol adaptively uses the amplify-and-forward and decode-and-forward whether a relay dec...

The use of intermediate terminals for relaying traffic in infrastructure based wireless systems promises improvements in capacity, energy efficiency and coverage. This paper studies the possibility to increase capacity using intermediate mobile terminals as relayers, especially when using a second frequency to perform relaying in addition to a cell’s primary frequency. This second frequency is ...

We consider a simple network consisting of a source, a half-duplex decode-and-forward relay with a buffer, and a destination. We assume that the direct source-destination link is not available and all links undergo fading. We propose two new buffer-aided relaying schemes with different requirements regarding the availability of channel state information at the transmitter (CSIT). In the first s...

We propose LDPC code designs for the half-duplex relay channel. Our designs mimic the information theoretic random coding scheme for decode-and-forward relaying. An important advantage of our scheme is that it is built entirely of single-user codes that can be decoded by belief propagation. The optimization of relay LDPC code profiles presents unique challenges, which are met by using the densi...