Forward error correction decoding for WiMAX and 3GPP LTE modems

Abstract

Abstract-In this paper, we review the requirements for forward error correction (FEC) decoding for next generation wireless modems -mobile Worldwide Interoperability for Microwave Access (WiMAX) and third generation partnership project long term evolution (3GPP LTE). FEC decoder consists of mainly three components: control channel decoder, data channel decoder, and hybrid automatic repeat query (HARQ) combining. Control channel decoder is constrained by latency budget which impacts buffering as well as power management of modem signal processing chains. For WiMAX, both Viterbi and Turbo decoders are required to receive control channel while for LTE, only Viterbi decoder is required. For data-channel, a highthroughput Turbo decoder is required to support high data rate. HARQ combining is mainly dominated by memory size and bandwidth requirements given the maximum data rate, maximum number of HARQ processes and re-transmission formats. We analyze the requirements and discuss possible candidate architectures for three components.

A 150Mbit/s 3GPP LTE Turbo code decoder

“…Using next iteration initialization instead of acquisition [13], [14] also does not achieve the required communications performance which has to be near to nonwindowed, continuous decoding in the limit of 6 to 7 decoding iterations for the specified thoughput of 150Ṁbit/s. Note that for 100 Mbit/s LTE [10], [13] a code rate of about 2 / 3 (2 MIMO layers) is used. In this case, a smaller acquisition length or NII is sufficient.…”

“…The most widely used parallel decoder architecture is based on parallel working MAP decoders [6]- [8], [10]- [12], [17]. In this architecture, a data block of length BL is divided into N sub-blocks of length SBL.…”

Towards an optimal transmission of SDUs in IEEE 802.16e WiMAX systems

“…[25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] if to mention a few (the interested reader can find in [5,42] a very good survey on WiMAX performance). Most of the papers deal with scheduling methods and the efficiency of transport layer protocols in IEEE 802.16e systems.…”

Performance Evaluation of Physical Layer of Mobile WiMAX System by Implementing Hybrid Channel Coding Scheme

“…ML algorithm is too complex, but viterbi algorithm eliminates least likely trellis path at each transmission stage and reduces decoding complexity with early rejection of unlike paths and concentrating on Survival paths of the trellis. In this way, viterbi decoding algorithm improves the efficiency of convolution codes [17].…”