Frequency-dependent modulation and coding rates for LTE link adaptation in static conditions

Javier Lorca, Carlos F. Lopez

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)
84 Downloads (Pure)

Abstract

OFDM wireless cellular systems rely on link adaptation in order to match the Modulation and Coding Scheme (MCS) of the transmission blocks with the dynamic channel conditions experienced at the receive side. For simplicity, Long-Term Evolution (LTE) systems consider a single MCS format per codeword, which is optimized according to the average frequency response over the user's allocated bandwidth. When the channel coherence bandwidth is smaller than the user bandwidth, the constituent codeblocks experience significantly different channel responses, thus rendering link adaptation less effective. This paper proposes a frequency-dependent link adaptation mechanism whereby codeblocks are independently assigned different MCS values that can be fine-tuned to the frequency characteristics of the channel. Post-detection SINR values at the receive side are exploited (instead of CQI values), along with horizontal mapping of resources with two variants: direct mapping and diversity mapping. A suitable in-band signaling scheme for the codeblock sizes and modulations is also described. Link-level simulations show moderate increases in median throughput, but significant improvements in instantaneous throughput, for a broad range of SINR conditions. The proposed scheme can be particularly beneficial when very large signal bandwidths are used as foreseen in future 5G cellular systems.

Original languageEnglish
Title of host publication2016 IEEE 27th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC)
PublisherIEEE
ISBN (Electronic)9781509032549
DOIs
Publication statusPublished - 21 Dec 2016
Event27th annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications 2016 - Valencia, Spain
Duration: 4 Sep 20167 Sep 2016

Publication series

NameIEEE International Symposium on Personal, Indoor, and Mobile Radio Communications workshops
PublisherIEEE
ISSN (Electronic)2166-9589

Conference

Conference27th annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications 2016
Abbreviated titlePIMRC'16
CountrySpain
CityValencia
Period4/09/167/09/16

Keywords

  • effective SINR
  • link adaptation
  • Link-to-System
  • MCS
  • variable rate

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Frequency-dependent modulation and coding rates for LTE link adaptation in static conditions'. Together they form a unique fingerprint.

  • Cite this

    Lorca, J., & Lopez, C. F. (2016). Frequency-dependent modulation and coding rates for LTE link adaptation in static conditions. In 2016 IEEE 27th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC) [7794828] (IEEE International Symposium on Personal, Indoor, and Mobile Radio Communications workshops). IEEE. https://doi.org/10.1109/PIMRC.2016.7794828