— In this paper, an algorithm for construction of multiple sets of two dimensional (2D) or matrix unipolar (optical) orthogonal codes has been proposed. Representations of these 2D codes in difference of positions representation (DoPR) have also been discussed along-with conventional weighted positions representation (WPR) of the code. This paper also proposes less complex methods for calculati...

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...

Time reversal (TR) has been proposed as a competitive precoding strategy for low-complexity devices relying on ultra-wideband waveforms, it shifts the signal processing complexity to transmitter side. This transmit paradigm can address need low-power, receivers, which is particularly important Internet of Things. Due its spatio-temporal focusing property, TR also used design multiple access sch...

A complete complementary/prime/shifted prime (CPS) code family for the optical code-division multiple-access (OCDMA) system is proposed. Based on the ability of complete complementary (CC) code, the multiple-access interference (MAI) can be suppressed and eliminated via spectral amplitude coding (SAC) OCDMA system under asynchronous/synchronous transmission. By utilizing the shifted prime (SP) ...

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...

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...