15,241 research outputs found
Cooperative Transmission Protocols with High Spectral Efficiency and High Diversity Order Using Multiuser Detection and Network Coding
Cooperative transmission is an emerging communication technique that takes
advantages of the broadcast nature of wireless channels. However, due to low
spectral efficiency and the requirement of orthogonal channels, its potential
for use in future wireless networks is limited. In this paper, by making use of
multiuser detection (MUD) and network coding, cooperative transmission
protocols with high spectral efficiency, diversity order, and coding gain are
developed. Compared with the traditional cooperative transmission protocols
with single-user detection, in which the diversity gain is only for one source
user, the proposed MUD cooperative transmission protocols have the merits that
the improvement of one user's link can also benefit the other users. In
addition, using MUD at the relay provides an environment in which network
coding can be employed. The coding gain and high diversity order can be
obtained by fully utilizing the link between the relay and the destination.
From the analysis and simulation results, it is seen that the proposed
protocols achieve higher diversity gain, better asymptotic efficiency, and
lower bit error rate, compared to traditional MUD and to existing cooperative
transmission protocols.Comment: to appear, in the proceedings of IEEE International Conference on
Communications, Glasgow, Scotland, 24-28 June 200
A Listing of Current Books
Abstract—We investigate cooperative strategies for relay-aided multi-source multi-destination wireless networks with backhaul support. Each source multicasts information to all destinations using a shared relay. We study cooperative strategies based on different network coding (NC) schemes, namely, finite field NC (FNC), linear NC (LNC), and lattice coding. To further exploit the backhaul connection, we also propose NC-based beam-forming (NBF). We measure the performance in term of achievable rates over Gaussian channels and observe significant gains over a benchmark scheme. The benefit of using backhaul is also clearly demonstrated in most of scenarios. I
Network Coded Modulation for Two Way Relay Networks
Modern wireless networks use cooperative relaying to expand its coverage area. Wireless relaying allows mobile terminals toparticipate in transmission even when these terminals are not being the initial source or final destination. This can be achieved in differentways ranging from simple conventional relaying to more sophisticated coding at terminal and relay nodes to improve transmissionperformance. The proposed work here studied such system by simulating different coding techniques to be used in two way relay networkcoding (TWRC). Some of these techniques were previously proposed to improve transmission performance in conventional datacommunication systems. BER performance of different arrangements of coding and relaying schemes are evaluated using computersimulation tests. Ideal AWGN channel model and standard wireless channel models for wireless networks are considered in the simulationtests. The results have been shown that coding schemes such as Trellis Coded Modulation (TCM) and Repeat Accumulate (RA) codes aremore suitable in two way relaying networks. Over AWGN, TCM-8PSK improves BER performance by at least 2 dB at high SNR fordifferent relaying arrangements. For fading channels, this advantage is slightly reduced. Regenerative repeating at relay node seems to be apromising arrangement. It seems that there is no sense in using RA codes over fading channels due to its poor performance and relativelylower speed caused by repetitions
- …