Channel coding represents a crucial signal processing procedure in modern mobile communications. The idea of an adaptable SOVA/log-MAP turbo decoder has been well addressed and discussed in published literature. Our work shows that such a decoder can be implemented in LTE mobile communications standard for different mobile channels.
Firstly, we study the implementation of the adaptable SOVA/log-MAP turbo decoder in LTE standard for uncorrelated Rayleigh fading and AWGN channels, considering BER performance and complexity. We concentrate on physical shared channel and use pipeline turbo decoder architecture with 12 iterations. We examine two data rates and for each one we consider the nine possible QCIs using five frame lengths.
Secondly, we study the implementation of the adaptable SOVA/log-MAP turbo decoder for flat Rayleigh fading channel. Particularly, this decoder is shown to adapt dynamically to different service scenarios, considering parameters like BER performance and complexity for indoor/low range outdoor operating environment (mobile speed of 4 km/h).
Finally, for physical shared channel (uplink and downlink) we consider BLER or FER performance in our analysis. We examine two data rates and for each one we consider the nine possible QCIs using five frame lengths. Considering BLER and delay limitations for each QCI, log-MAP is proposed for small frames for all data rates, QCIs and AWGN channel. SOVA represents the proposed choice for larger frame lengths for both AWGN and uncorrelated Rayleigh fading channels and for low data rates.
Costas Chaikalis was born in Athens, Greece, on March 1973. He received the B.Sc. degree in electrical engineering in 1995 from Technological Educational Institute of Lamia, Greece. He also received the M.Sc. and Ph.D. degrees from Department of Electronics and Telecommunications, University of Bradford, Bradford, UK in 1999 and 2003, respectively. During his doctoral studies he worked as a Research Assistant for Mobile Virtual Center of Excellence (Mobile VCE), Terminals Group, UK. Costas Chaikalis is the author or co-author of about 40 technical papers published in international conferences, journals and book chapters. His research interests are in all areas of mobile communications but especially in forward error correction coding, reconfigurable (software radio) architectures, cross layer architectures and DSP applications. Currently, he is a lecturer in the Department of Computer Science & Engineering, Technological Educational Institute (TEI) of Thessaly, Larissa, Greece.