Title :
Iterative source-channel decoding with cross-layer support for wireless VoIP
Author :
Breddermann, Tobias ; Lüders, Helge ; Vary, Peter ; Aktas, Ismet ; Schmidt, Florian
Author_Institution :
Inst. of Commun. Syst. & Data Process. (iNd), RWTH Aachen Univ., Aachen, Germany
Abstract :
This paper presents a cross-layer approach for iterative source-channel decoding (ISCD) in wireless VoIP networks. The novelty of the proposed method is the incorporation of both, speech bits as well as protocol header bits, into the ISCD process. The header bits take the role of pilot bits having perfect reliability. These bits are distributed over the frame as strong supporting points for the MAP decoder which. results in a significant enhancement of the output speech quality compared to the benchmark scheme using ISCD for speech only. For this approach, we exploit cross-layer concepts that support the direct communication between non-adjacent layers. These concepts enable the iterative exchange of extrinsic information between the source decoder located on the application layer and the channel decoder located on the physical layer. This technique can also be applied to audio and video transmission.
Keywords :
Internet telephony; channel coding; iterative decoding; maximum likelihood decoding; radio networks; source coding; speech enhancement; ISCD process; MAP decoder; audio transmission; channel decoder; cross-layer support; digital mobile radio communication systems; iterative exchange; iterative source-channel decoding; output speech quality enhancement; protocol; source decoder; video transmission; wireless VoIP networks; Bandwidth; Data processing; Internet telephony; Iterative decoding; Iterative methods; Open systems; Physical layer; Redundancy; Speech enhancement; Speech processing;
Conference_Titel :
Source and Channel Coding (SCC), 2010 International ITG Conference on
Conference_Location :
Siegen
Print_ISBN :
978-1-4244-6872-0
Electronic_ISBN :
978-3-8007-3211-1