Spreading sequence design and theoretical limits for quasisynchronous CDMA systems
EURASIP Journal on Wireless Communications and Networking - Special issue on innovative signal transmission and detection techniques for next generation cellular CDMA systems
Overloaded CDMA systems with displaced binary signatures
EURASIP Journal on Wireless Communications and Networking - Special issue on innovative signal transmission and detection techniques for next generation cellular CDMA systems
An improved overloading scheme for downlink CDMA
EURASIP Journal on Applied Signal Processing
The finite Heisenberg-Weyl groups in radar and communications
EURASIP Journal on Applied Signal Processing
Gold codes, Hadamard partitions and the security of CDMA systems
Designs, Codes and Cryptography
Overloading cellular DS-CDMA: a bandwidth-efficient scheme for capacity enhancement
ICDCN'08 Proceedings of the 9th international conference on Distributed computing and networking
IEEE Transactions on Information Theory
Unitary space-time constellations based on quasi-orthogonal sequences
IEEE Transactions on Communications
IEEE Transactions on Information Theory
The Assignment of CDMA Spreading Codes Constructed from Hadamard Matrices and Almost Bent Functions
Wireless Personal Communications: An International Journal
Hi-index | 754.96 |
The notion of quasi-orthogonal sequence (QOS) as a means of increasing the number of channels in synchronous code-division multiple-access (CDMA) systems that employ Walsh sequences for spreading information signals and separating channels is introduced. It is shown that a QOS sequence may be regarded as a class of Bent (almost Bent) functions possessing, in addition, a certain window property. Such sequences while increasing the system capacity, minimize interference to the existing set of Walsh sequences. The window property gives the system the ability to handle variable data rates. A general procedure of constructing QOSs from well-known families of binary sequences with good correlation, including the Kasami and Gold (1967) sequence families, as well as from the binary Kerdock code is provided. Examples of QOSs are presented for small lengths. Some examples of quaternary QOSs drawn from Family A are also included