Non-orthogonal multiple access (NOMA), in particular pattern division (PDMA), has been recently considered as the critical technologies deployed for 5G applications. However, optimizing power allocation (PA) at base station (BS) to increase sum throughput of downlink (DL) PDMA system still remains a challenge. Although this problem explored some extent by assuming that BS can obtain perfect cha...

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...

In CDMA (Code - Division Multiple - Access) systems multi - user accessing of a channel is possible. Under the assumptions of Optimum multi - user and decorrelating detector in CDMA systems. By using signals with zero and / or identical cross correlations, a simple and expandable decorrelating detector with optimum efficiency which can be easily implemented are proposed. Constructing these sign...

Currently we see a multitude of emerging ideas that aim to provide information and higher level services for mobile users Starting with simple voice communications and information browsing they reach towards multi component services like personal travel assistance comprising wireless communication information technology and navigation Provocatively we could argue that the latter ones are likely...

0163-6804/98/$10.00 © 1998 IEEE avelength-division multiplexing (WDM) as a system concept goes back to the early 1970s. At that time, however, it usually only implied the use of two wavelengths, generally one in each of the 1300 nm and 1550 nm windows to enable full duplex transmission. Furthermore, the development of point-to-point links was the main thrust of WDM research throughout the 1970s...

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...

In rate division multiple access (RDMA), transmission interval between pulses of each user, also referred as user period, is made different so that pulses transmitted by other users can be interleaved within that interval. To reduce collision probability in such scheme, each node requires to generate relative prime from which the user period is computed. We present a novel scheme to generate un...

Abstract— Orthogonal frequency division multiplexing (OFDM) is an important technique to support high speed transmission of broadband traffic in wireless networks, especially broadband wireless local area networks (LANs). Based on OFDM, a new multiple access scheme, called OFDM-TDMA with subcarrier allocation (OFDMTDMA/SA), is introduced in this paper. It provides more flexibility in resource a...

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...