Application of syndrome based Turbo decoding with adaptive computational complexity in LTE downlink

J Geldmacher,J Götze,M Kosakowski,K Hueske

doi:10.5194/ars-10-159-2012

Abstract

Abstract. This paper describes the application of an adaptive complexity decoder for the Long Term Evolution (LTE) downlink Turbo code. The proposed decoding approach is based on the block syndrome decoding principle and enables adaptive reduction of decoding effort depending on current SNR and iteration number with negligible influence on decoding performance. Numerical results in context of LTE downlink using typical mobile channels are used to demonstrate the efficiency of the approach.

Highlights

Mobile communication usage has shifted from mainly speech-centered use to highly bandwidth demanding data communication: A mobile phone is no longer just a phone, but it has become a personal communication and multimedia device, which is used for internet browsing, video and audio streaming, online-based navigation etc
This paper describes the application of an adaptive complexity decoder for the Long Term Evolution (LTE) downlink Turbo code
The proposed decoding approach is based on the block syndrome decoding principle and enables adaptive reduction of decoding effort depending on current SNR and iteration number with negligible influence on decoding performance

Summary

Introduction

Mobile communication usage has shifted from mainly speech-centered use to highly bandwidth demanding data communication: A mobile phone is no longer just a phone, but it has become a personal communication and multimedia device, which is used for internet browsing, video and audio streaming, online-based navigation etc. A different decoding approach is considered which is based on the so called syndrome former HT of the underlying code While this decoder is equivalent to the conventional decoder in terms of trellis complexity and decoding performance, it can be modified to achieve adaptive decoding complexity based on the so called Block Syndrome Decoding (BSD) approach. The BSD concept has been described earlier in context of Viterbi decoding (Geldmacher et al, 2009) and Turbo equalization (Geldmacher et al, 2010; Hueske et al, 2010). Applying it to Turbo decoding is, not straightforward as will be shown in this paper, but requires the extension of the Turbo decoder by means of a pre-correction of the constituent decoders inputs.

Block syndrome decoding

Syndrome based Turbo decoder