Techniques de surcharge en utilisateurs d’un canal à accès multiple

Abstract : This thesis is dedicated to the channel overloading concept, which refers to the situation in which a system accommodates a greater number of users than allowed by the use of orthogonal signal waveforms. We showed the existence of two families of construction at the transmitter side allowing a spectral efficiency gain by the increase of the number of users. The first family of techniques includes the schemes making use of combinations of orthogonal CDMA and possibly of TDMA, and a construction proposed in the literature by Ross and Taylor. We investigated and compared the performance given by different methods of multiuser detection based on an iterative interference cancellation principle, which can be applied to these schemes in the absence of coding, on a Gaussian channel or on a non-selective Rayleigh fading channel. We next considered schemes from the second family of construction: on the one hand a scheme proposed following the interpretation of the above mentioned schemes as multilevel coding, and on the other hand IDMA (Interleave-Division Multiple Access), whose performance was studied on a Gaussian channel without coding, and compared to the other channel overloading techniques. Finally, we presented through a general matrix formalism some iterative techniques adapted to schemes with channel coding, and which can be used on a Gaussian or a Rayleigh multipath channel. Thus, several receiver structures adapted to each scheme (CDMA or IDMA) were proposed.
Document type :
Theses
Complete list of metadatas

Cited literature [133 references]  Display  Hide  Download

https://hal-upec-upem.archives-ouvertes.fr/tel-01765868
Contributor : Florence Nadal <>
Submitted on : Friday, April 13, 2018 - 10:50:31 AM
Last modification on : Monday, April 23, 2018 - 10:37:22 AM

File

These_Nadal_ultime.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01765868, version 1

Collections

Citation

Florence Nadal. Techniques de surcharge en utilisateurs d’un canal à accès multiple. Traitement du signal et de l'image [eess.SP]. SUPELEC, 2006. Français. ⟨tel-01765868⟩

Share

Metrics

Record views

79

Files downloads

47