Asymptotically Optimum Energy Profile for Successive Interference Cancellation in DS-CDMA under a Power Unbalance Constraint

Author

Sala, Josep ; Rey, Francesc ; Villares, Javier

Author_Institution

Dept. of Signal Theor. & Commun., Tech. Univ. of Catalonia, Barcelona, Spain

Volume

16

Issue

2

fYear

2012

fDate

2/1/2012 12:00:00 AM

Firstpage

172

Lastpage

175

Abstract

A new Ordinary Differential Equation (ODE) governing the SNIR evolution of a Successive Interference Canceller (SIC) for DS-CDMA is derived when the number of users tends to infinity and all users share the same channel encoder. Using Variational Calculus, this ODE is applied to obtaining the energy profile that maximizes the average spectral efficiency when a constraint on the power unbalance (maximum power to minimum power ratio) of received users is enforced. The conditions for extremality of the optimum energy profile are established in terms of the common encoder´s Packet Error Rate (PER) function.

Keywords

code division multiple access; differential equations; error statistics; interference suppression; spread spectrum communication; variational techniques; DS-CDMA; ODE; PER function; SIC; SNIR evolution; asymptotically optimum energy profile; channel encoder; ordinary differential equation; packet error rate; power unbalance constraint; spectral efficiency; successive interference cancellation; variational calculus; Differential equations; Digital video broadcasting; Interference; Multiaccess communication; Optimization; Silicon carbide; Telecommunication standards; CDMA; Successive interference cancellation; differential equation; error propagation; packet error rate; power unbalance; variational calculus;

fLanguage

English

Journal_Title

Communications Letters, IEEE

Publisher

ieee

ISSN

1089-7798

Type

jour

DOI

10.1109/LCOMM.2011.121311.111964

Filename

6109196