In this paper, we investigate the performance of a recently proposed multiple-access system, namely, partitionspreading CDMA (PS-CDMA). We show via variance evolution that the asymptotic channel throughput of PS-CDMA improves monotonically as the number of partitions increases. The fundamental limit of the PS-CDMA system is calculated by evaluating the spectral efficiency of the layered channel...

Reed-Muller codes are studied for peak power control in multicarrier code-division multiple access (MC-CDMA) communication systems. In a coded MC-CDMA system, the information data multiplexed from users is encoded by a Reed-Muller subcode and the codeword is fully-loaded to Walsh-Hadamard spreading sequences. The polynomial representation of a coded MC-CDMA signal is established for theoretical...

Analog frequency modulated (FM) systems offer advantages of reliable speech quality and simplicity, whereas code division multiple access (CDMA) systems promise high capacity, resistance to multipath fading, and simplified frequency planning. In this thesis, we investigate the performance of a wireless local loop (WLL) system that uses the frequency modulation with the CDMA technique. The perfo...

Abstract The multiple-access interference (MAI) limits the transmission performance of the CDMA uplink transmission. In this paper, we propose a generalized chip-interleaved (GCI)-CDMA with 2-dimensional (2D)-OVSF spreading. Since MAI can be removed, single-user frequency-domain equalization based on the MMSE criterion can be applied for signal detection. The GCI-CDMA allows flexible multi-rate...

In this paper, a multi-coded CDMA system employing a variable spreading gain (VSG) approach is proposed for high-rate applications, which is based on two algorithms for selecting multi-code set. From the simulation results, in addition to simple receiver structure thanks to level clipping, the multi-coded VSG CDMA system provides an high bit rate transmission, while maintaining an acceptable pe...

Minimax problems arise in a wide range of important applications including robust adversarial learning and Generative Adversarial Network (GAN) training. Recently, algorithms for minimax the Federated Learning (FL) paradigm have received considerable interest. Existing federated general require full aggregation (i.e., local model information from all clients) each training round. Thus, they are...

Relying on block-symbol spreading and judicious design of user codes, this paper builds on the generalized multicarrier (GMC) quasisynchronous CDMA system that is capable of multiuser interference (MUI) elimination and intersymbol interference (ISI) suppression with guaranteed symbol recovery, regardless of the wireless frequency-selective channels. GMC-CDMA affords an alldigital unifying frame...

This paper gives a review of DS-CDMA, RAKE receiver and multicarrier DS-CDMA as well as a proposal and numerical result for a multicarrier DS-CDMA system. This paper is organized as follows: Section I introduces the development of methods for wireless communication over multipath fading channel. Section II gives Turin's evaluation of the e ects of multipath and fading on the performance of DS-C...

Direct sequence (DS) and Multi-carrier (MC) code division multiple access (CDMA) are competing schemes for wireless multiple access systems. They have been studied and compared by many researchers. Time and frequency domains have long been used to represent linear systems in dual forms. In this paper it is shown, using time-frequency duality, that DS and MC can be considered dual CDMA systems o...