An alternative code-division multiple-access (CDMA) scheme to spread spectrum (SS), called spread time (ST) is proposed for badlimited multiple-access channels. ST-CDMA can be considered the be-frequency dual of SS-CDMA. In ST-GDMA pslendsraodan (PN) sequences are assigned to each user, and the Fourier tcrursf@rm of the transmitted pulse for a given user is d&mined by modulating the phase of th...

The use of spread spectrum signaling, motivated primarily by its antijamming capabilities in military applications, leads naturally to the use of Code Division Multiple Access (CDMA) techniques that permit the successful simultaneous transmission by a number of users over a wideband channel. In this paper we address some of the major issues that are associated with the design of multiple access...

The optical code division multiple access (optical CDMA) systems is a versatile multiple access technique as compared to time division multiple access (TDMA) and wavelength division multiple access (WDMA). In optical CDMA, the users are assigned unique codes whereas the WDMA and TDMA systems users are assigned different wavelengths or time slots so as to distinguish the data recovered at the re...

A crucial open problem inS large-scale quantum networks is how to efficiently transmit quantum data among many pairs of users via a common data-transmission medium. We propose a solution by developing a quantum code division multiple access (q-CDMA) approach in which quantum information is chaotically encoded to spread its spectral content, and then decoded via chaos synchronization to separate...

Recently, blind multi-user detection has become an important topic in code division multiple access (CDMA) systems. Direct-Sequence Spread Spectrum (DSSS) signals are well-known due to their low probability of detection, and secure communication. In this article, the problem of blind multi-user detection is studied in variable processing gain direct-sequence code division multiple access (VPG D...