Uncertainty principles, extractors, and explicit embeddings of l2 into l1
Proceedings of the thirty-ninth annual ACM symposium on Theory of computing
Kerdock codes for limited feedback precoded MIMO systems
IEEE Transactions on Signal Processing
An improved multicode CDMA transmission method for ad hoc networks
WCNC'09 Proceedings of the 2009 IEEE conference on Wireless Communications & Networking Conference
Unit time-phase signal sets: Bounds and constructions
Cryptography and Communications
Journal of the ACM (JACM)
| Hi-index | 754.84 |
Sum capacity optimal signatures in synchronous code-division multiple-access (CDMA) systems are functions of the codebook length as well as the number of active users. A new signature set must be assigned every time the number of active users changes. This correspondence considers signature sets that are less sensitive to changes in the number of active users. Equiangular signature sequences are proven to solve a certain max-min signal-to-interference-plus-noise problem, which results from their interference invariance. Unions of orthonormal bases have subsets that come close to satisfying the Welch bound. Bounds on the maximum number of bases with minimum maximum correlation are derived and a new construction algorithm is provided. Connections are made between these signature design problems, Grassmannian line packing, frame theory, and algebraic geometry