Link Adaptation Strategies for Cellular Downlink with low-fixed-rate D2D Underlay: A 3GPP LTE Case Study
Author
Fernandes Lopes Marques Eduardo, Afonso
Term
4. term
Education
Publication year
2014
Pages
69
Abstract
Dette speciale undersøger linktilpasningsstrategier for LTE-nedlink, når en lav-fasthastigheds D2D-forbindelse underlægges samme frekvensressourcer, med successiv interferensannullering (SIC) som nøglemekanisme. Scenariet er, at en basestation sender til et UE, mens en maskintypenhed samtidig kommunikerer D2D til samme UE; kun basestationen kan udføre linktilpasning. Forskningsspørgsmålet er, hvordan man udformer linktilpasning, der både muliggør interferensannullering og balancerer pålidelighed og spektral effektivitet. Arbejdet antager LTE-fysiklaget i SISO-tilstand og blok-flad Rayleigh-fading for begge links, og præsenterer to SIC-bevidste strategier: en nul-udfaldsregel, der sigter mod minimal outage med begrænset information om D2D-linket, og en vægtet regel, der kræver mere information for at maksimere systemeffektiviteten. Strategierne evalueres i en 3GPP LTE case med link- og systemniveau-simuleringer, herunder implementering af en SIC-modtager og LTE-typiske komponenter som SINR-til-CQI-afbildning. Resultaterne vurderes ud fra gennemsnitlig MCS, BLER, gennemstrømning pr. allokeret ressourceblok og kombineret spektral effektivitet; på systemniveau beskrives et indendørs on-body MTD-scenarie inden for et METIS-rammeværk. Analysen fremhæver praktiske kompromiser mellem robust nul-udfaldsdrift med begrænset information og højere effektivitet opnået gennem yderligere linkinformation.
This thesis examines link adaptation strategies for the LTE downlink when a low fixed-rate D2D link underlays the same resources, using successive interference cancellation (SIC) as the key mechanism. The scenario consists of a base station transmitting to a UE while a machine-type device simultaneously communicates D2D with the same UE; only the base station can perform link adaptation. The research question is how to design link adaptation that both enables interference cancellation and balances reliability and spectral efficiency. The work assumes the LTE physical layer in SISO mode and block-flat Rayleigh fading on both links, and introduces two SIC-aware strategies: a zero-outage rule that targets minimal outage with limited information about the D2D link, and a weighted rule that leverages additional information to maximize system efficiency. The strategies are evaluated in a 3GPP LTE case using link- and system-level simulations, including an implemented SIC receiver and LTE-standard components such as SINR-to-CQI mapping. Performance is assessed via average MCS, BLER, throughput per allocated resource block, and combined spectral efficiency; at system level, an indoor on-body MTD scenario is described within a METIS framework. The results highlight practical trade-offs between robust zero-outage operation with limited information and higher efficiency achieved by exploiting extra link information.
[This summary has been generated with the help of AI directly from the project (PDF)]
Keywords
M2M ; D2D Underlay ; SIC ; LTE ; LA
Documents