An Algorithm for Unit Tight Frames with Constant Chip Magnitude Design in Overloaded CDMA Systems
Paul Cotae, Matt Aguirre, Mehdi Shadaram · 2006
We developed an algorithm which allows obtaining a Gram matrix having a particular pattern for crosscorrelations of the signature sequences. When it is used for real numbers, unit tight frame signature sets are obtained, as they are required by 2G or 3G CDMA systems. When this algorithm is used for complex numbers, complex valued signature sets with constant chip magnitude are obtained. The results are derived in the context of synchronous CDMA systems and numerical results are provided to illustrate the mathematical formalism.