A power efficient embedded modulation scheme for addressing multiple users in the downlink

Author

Janssen, Gerard J M

Author_Institution

Wireless & Mobile Commun. Group, Delft Univ. of Technol., Netherlands

Volume

3

fYear

2005

fDate

30 May-1 June 2005

Firstpage

1930

Abstract

A power efficient embedded QAM (EQAM) modulation scheme, for addressing multiple users simultaneously in the downlink of a cellular system, is proposed. The EQAM modulation is based on stacking a number of M-PSK (M = 2,4) signals each intended for a different user. The optimum phase relations between the users´ signals and the required link quality dependent amplitudes, are given. The power penalty is evaluated for geometrically related link qualities and for a number of heuristic user assignment schemes in a single cell system. Compared to a conventional QAM-scheme with the same spectral efficiency, the power penalty for EQAM can be substantially lower, provided that users with sufficiently different link qualities are addressed with the same signal.

Keywords

cellular radio; quadrature amplitude modulation; radio links; QAM; cellular system; downlink; heuristic user assignment schemes; link quality; multiple users; power efficient embedded modulation scheme; power penalty; Base stations; Digital video broadcasting; Downlink; Interference; Mobile communication; Narrowband; Phase shift keying; Power system modeling; Quadrature amplitude modulation; Stacking;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference, 2005. VTC 2005-Spring. 2005 IEEE 61st

ISSN

1550-2252

Print_ISBN

0-7803-8887-9

Type

conf

DOI

10.1109/VETECS.2005.1543659

Filename

1543659