In classical infrastructure-based wireless systems such as access pointequipped wireless LANs, all mobile terminals communicate directly with the access point. In order to improve the capacity or energy efficiency of such systems, the use of mobile terminals as intermediate relays has been proposed. The rationale is that intermediate relays reduce the communication distance and hence the emitte...

Peer discovery via distributed message relaying is an important function of a P2P system in which the resources/services provided by peers and service/resource providers may change frequently. The usual searching protocols create huge burden on communications or cause long response time. Appropriate incentives are required to avoid free-riding and achieve efficient cooperations in message relay...

In this paper, a multi-antenna assisted full-duplex (FD) relaying scheme with reliability-aware iterative decoding at the destination node is proposed to improve system spectral efficiency and reliability. This scheme allows the multi-antenna based FD relay node cancel the self-interference with QR-decomposition and forward its decoded signal to the destination node regardless the decoding erro...

Performance of multi-hop MIMO relay channels under the amplify-and-forward and decode-and-forward protocols are compared via the capacity and SNR gains. In an N hop channel of linear topology with multi-antenna source and destination and single-antenna relay nodes, the capacity gain of the DF relaying over the AF one does not exceed log2N bit/s/Hz and its SNR gain does not exceed N , for any ch...

In multi-hop communication systems, two-way relaying is one of the solutions to mitigate the spectral efficiency loss caused by a half-duplex transmission. In this paper, a simple two-way relaying scheme is proposed for two-hop two-user multiple input multiple output (MIMO) systems. In the proposed system, a base station and a relay station (RS), both equipped with two antennas, form a point-to...

The concept of cooperative relaying promises gains in robustness and energy efficiency in wireless networks. This survey gives an introduction and overview of promising methods that can be used for cooperative relaying: relay selection protocols, cooperative channel and network coding, and physical layer aspects such as cooperative modulation. The particular methods can be seen as building bloc...

Multihop network is an approach utilizing distributed wireless stations for relaying. In this system, area size, coverage and total transmit power efficiency can be improved. It is shown by computer simulations that the cooperative relaying scheme provides transmit diversity effect, and can offer much better performance compared with that of non-cooperation case. To confirm this superior perfor...

The use of ad-hoc-based multi-hop relaying has been advocated as a means to increase the capacity and energy-efficiency of wireless networks. It is one of the goals of the IBMS project to investigate the potential of such ad-hoc relaying, using HiperLAN/2 as a case study. To realize relaying in a HiperLAN/2 network, the HiperLAN/2 protocol needs to be extended. This paper describes a standard-c...

In classical infrastructure-based wireless systems, all mobile terminals communicate directly with the access point. In such systems, the transmission capacity, i.e., the amount of traffic successfully communicated to/from the access point, is important. This paper studies the possibility to increase this capacity by using mobile terminals as intermediate relays. These relays reduce the communi...

A cooperative relaying system with transmission scheduling is investigated. Cooperative relaying is composed of multiple links because the source sends the data to more than one receiver, and the destination receives multiple data transmitted by more than one transmitter. Therefore, if the source can transmit the data when the channel gains of the links are high, it is not clear which channel g...