Title :
Weighted Gram Bigenvalue Characterization of Sum Capacity of Overloaded S-CDMA
Author_Institution :
Texas Univ., San Antonio, TX
Abstract :
By using a Gramian matrix approach and majorization theory, a complete eigenspaces characterization of those sequences which maximize the sum capacity of the single cell overloaded S-CDMA is given. The main result of this paper is a procedure of testing the eigenvalues of the weighted Gram matrix associated to spreading signature in order to characterize the sum capacity. In contrast to the previous results, we prove that the sum capacity of overloaded S-CDMA systems is maximized when all users belong to only one eigenspace: the linear dependent one. Illustrative numerical examples are provided to support our analysis.
Keywords :
code division multiple access; eigenvalues and eigenfunctions; sequences; spread spectrum communication; Gramian matrix approach; code division multiple access; eigenspaces characterization; eigenvalue; majorization theory; overloaded S-CDMA; sequence; spreading signature; Correlation; Covariance matrix; Eigenvalues and eigenfunctions; Linear matrix inequalities; Multiple access interference; Power measurement; Sociotechnical systems; Spread spectrum communication; System testing; Transmitters; Total (Weighted) Squared Correlation; generalized Welch Bound Equality (WBE) sequences; multicellular systems; multiple access design; spread spectrum systems;
Conference_Titel :
Information Sciences and Systems, 2006 40th Annual Conference on
Conference_Location :
Princeton, NJ
Print_ISBN :
1-4244-0349-9
Electronic_ISBN :
1-4244-0350-2
DOI :
10.1109/CISS.2006.286379
