naa a22 4500 510796133 CHVBK 20180411083337.0 cr unu---uuuuu 180411e20130201xx s 000 0 eng 10.1007/s11277-012-0552-3 doi (NATIONALLICENCE)springer-10.1007/s11277-012-0552-3 Impact of Implicit Feedback Channel in Cooperative Relay Networks [Elektronische Daten] [Ashish James, A. Madhukumar, Surya Tio, Ernest Kurniawan] In a multi-node network, cooperation among nodes is an effective means to enhance coverage and potentially increase the capacity. For such systems, schemes based on incremental relaying have great potential to improve the spectral efficiency by adapting the transmission to time varying channel conditions. The performance enhancement brought about by the presence of relays in such incremental relaying based cooperative systems is dependent on the level of cooperation (based on the relay information quality) and on coordination among the nodes. Coordination is achieved through the use of feedback channels, which incurs significant bandwidth penalty and brings down the spectral efficiency. In order to mitigate this, one can exploit an implicit feedback channel available due to broadcast nature of relay transmissions. Instead of using dedicated feedback channels, the implicit feedback channel is used to measure the relay information quality. Based on this information, the transmitter (source/relay) for the additional coded (redundancy) bits is determined. Such a mechanism enhances the reliability as it ensures the availability of correct information at the destination node for decoding. This paper studies the impact of such an implicit feedback channel by employing powerful codes which exhibit inherent incremental redundancy features, such as rate-compatible codes (rate-compatible punctured convolutional (RCPC) codes and punctured low-density parity-check (LDPC) codes) and rateless codes (Luby Transform (LT) codes). Theoretical analyses of the proposed scheme are presented, and supported with results from extensive simulation studies. Springer Science+Business Media, LLC., 2012 Incremental relaying nationallicence Rateless codes nationallicence LT codes nationallicence Rate-compatible punctured convolutional (RCPC) codes nationallicence Low-density parity-check (LDPC) codes nationallicence Cooperative communication nationallicence James Ashish Centre for Multimedia and Network Technology, School of Computer Engineering, Nanyang Technological University, 639798, Singapore, Singapore aut Madhukumar A. Centre for Multimedia and Network Technology, School of Computer Engineering, Nanyang Technological University, 639798, Singapore, Singapore aut Tio Surya Centre for Multimedia and Network Technology, School of Computer Engineering, Nanyang Technological University, 639798, Singapore, Singapore aut Kurniawan Ernest Institute for Infocomm Research, A*STAR, 138632, Singapore, Singapore aut Wireless Personal Communications Springer US; http://www.springer-ny.com 68/4(2013-02-01), 1837-1870 0929-6212 68:4<1837 2013 68 11277 https://doi.org/10.1007/s11277-012-0552-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11277-012-0552-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- James Ashish Centre for Multimedia and Network Technology, School of Computer Engineering, Nanyang Technological University, 639798, Singapore, Singapore aut NATIONALLICENCE 700 1- Madhukumar A. Centre for Multimedia and Network Technology, School of Computer Engineering, Nanyang Technological University, 639798, Singapore, Singapore aut NATIONALLICENCE 700 1- Tio Surya Centre for Multimedia and Network Technology, School of Computer Engineering, Nanyang Technological University, 639798, Singapore, Singapore aut NATIONALLICENCE 700 1- Kurniawan Ernest Institute for Infocomm Research, A*STAR, 138632, Singapore, Singapore aut NATIONALLICENCE 773 0- Wireless Personal Communications Springer US; http://www.springer-ny.com 68/4(2013-02-01), 1837-1870 0929-6212 68:4<1837 2013 68 11277 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer