Publica
Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. Logconcavity of SIR and characterization of the feasible SIR region for CDMA channels
 Matthews, M.B. ; Naval Postgraduate School, Monterey/Calif.: ThirtySeventh Asilomar Conference on Signals, Systems & Computers 2003. Conference record. Vol.1 : November 9  12, 2003, Pacific Grove, California Piscataway, NJ: IEEE, 2003 ISBN: 0780381041 pp.413417 
 Asilomar Conference on Signals, Systems and Computers <37, 2003, Pacific Grove/Calif.> 

 English 
 Conference Paper 
 Fraunhofer HHI () 
Abstract
We consider a powercontrolled CDMA channel where each user is required to satisfy a certain qualityofservice (QoS) requirement. It is assumed that there is a onetoone relationship between a QoS parameter of interest and the signaltointerference ratio (SIR) at the output of a linear receiver. The set of all feasible QoS requirements is called the feasibility region. The paper shows under what conditions the feasibility region is a convex set. Furthermore, we prove that the SIR is a logconcave function of powers when the powers are expressed in logarithmic scale. These properties open the door to a widely developed theory for characterizing strategies to optimally allocate scarce resources in wireless communication networks.