Title :
Projection multiuser detectors for hierarchical cell structures in CDMA cellular systems
Author :
Catovic, Amer ; Tekinay, Sirin
Author_Institution :
New Jersey Inst. of Technol., Newark, NJ, USA
Abstract :
CDMA-only microcell/macrocell cellular systems have traditionally suffered from the near-far problem in the microcells located near the macrocell boundary. Strong macrocell interference in these microcells disables conventional single user detectors. We present techniques for multiuser receiver design that address this problem. The pre-processing stage, called the projection stage, which projects the received signal onto the space orthogonal to the subspace spanned by macrocell users signature sequences, is introduced. It is followed by the stage employing conventional multiuser detection techniques. This class of detectors, called projection multiuser detectors, solves the near-far problem in microcells located at the macrocell boundary, and provides equal treatment to all microcells, regardless of their location within the macrocell. We provide expressions for error probabilities and perform the performance comparison between different projected single user detector and the projected decorrelator
Keywords :
code division multiple access; error statistics; microcellular radio; multiuser channels; radio receivers; signal detection; CDMA cellular systems; error probability; hierarchical cell structures; macrocell boundary; macrocell interference; microcell/macrocell systems; microcells; multiuser receiver design; near-far problem; pre-processing stage; projected decorrelator; projected single user detector; projection multiuser detectors; projection stage; received signal; users signature sequences; Costs; Decorrelation; Detectors; Error probability; Frequency; Macrocell networks; Microcell networks; Multiaccess communication; Multiuser detection; Telecommunication traffic;
Conference_Titel :
Vehicular Technology Conference, 2001. VTC 2001 Spring. IEEE VTS 53rd
Conference_Location :
Rhodes
Print_ISBN :
0-7803-6728-6
DOI :
10.1109/VETECS.2001.945015