Small handsets performances for 4G LTE
Authors
Lamé, Jean-Baptiste ; Simone, Claudio
Term
10. term
Publication year
2012
Submitted on
2012-05-29
Pages
76
Abstract
Smartphones er små, men skal levere høj datahastighed. Det skaber nye udfordringer for design af håndsæt og antenner. I dette arbejde undersøger vi, hvordan forhold som især brugerens måde at holde og bruge telefonen på påvirker effektiviteten af et antennediversitetssystem (flere antenner, fx MIMO) i en lille telefon. Vi fokuserer på parametre som korrelation (hvor ens antennerne opfanger signalet), mean effective gain/MEG (antennens gennemsnitlige modtageevne i et mangfoldigt radiomiljø), branch power ratio/BPR (balancen mellem antennegrene), modtaget effekt og variationer i kanalkapacitet (den maksimale datarate). Analysen bygger på både simuleringer og en målekampagne fra Aalborg Universitet i Aalborg centrum i 2011. Vi udtrak data, grupperede dem og udførte statistiske analyser for at vurdere, hvordan hver parameter påvirker designet. I simuleringerne for to håndsæt så vi, at når en bruger var til stede, faldt korrelation, MEG og modtaget effekt i theta‑polarisation på tværs af de betragtede kanalmodeller (TAGA, AAU og isotropisk). I målingerne analyserede vi ti håndsæt med forskellige antennedesign i otte almindelige brugssituationer samt ydeevnen af SAM‑hoved og håndfantom. Resultaterne bekræftede, at høj korrelation forringer MIMO‑kapacitet, og vi identificerede, hvilke antennedesign der er mest følsomme over for at nå høj korrelation. Derimod har BPR kun begrænset betydning for kanalkapaciteten. Fremtidigt arbejde bør undersøge forskellige signal‑til‑støj‑forhold og forskellige teknikker til at kombinere antennesignaler.
Smartphones are small but expected to deliver high data rates, which creates new challenges for handset and antenna design. This study examines how factors—especially how people hold and use the phone—affect the efficiency of an antenna diversity system (multiple antennas, e.g., MIMO) in a small handset. We focus on parameters such as correlation (how similarly antennas receive the signal), mean effective gain/MEG (the antenna’s average ability to receive power in a multipath environment), branch power ratio/BPR (the power balance between antenna branches), received power, and variations in channel capacity (the maximum data rate). Our analysis combines simulations with a measurement campaign conducted by Aalborg University in downtown Aalborg in 2011. We extracted, grouped, and statistically analyzed the data to assess how each parameter influences design. In simulations of two handsets, we observed that the presence of a user reduced correlation, MEG, and received power in theta polarization across the considered channel models (TAGA, AAU, and isotropic). In measurements, we analyzed ten handsets with different antenna designs across eight common use cases, plus tests with SAM head and hand phantoms. The results confirmed that high correlation degrades MIMO capacity, and we identified which antenna designs are more prone to reaching high correlation. In contrast, BPR has only a limited impact on channel capacity. Future work should test different signal‑to‑noise ratios and antenna combining techniques.
[This abstract was generated with the help of AI]
Keywords
LTE ; 4G ; small handsets ; branch power ratio ; mean effective gain ; correlation ; capacity ; antenna diversity ; antenna ; channel ; MIMO ; MISO ; SISO ; SIMO ; MEG ; BPR
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