WCDMA-based radio over fibre system performance with multiple-user interference in multiple service transmission

When receiving high data rate in ultra-wideband (UWB) technology, many users have experienced multiple-user interference and intersymbol interference in the multipath reception technique. Structures have been proposed for implementing rake receivers to enhance their capabilities by reducing the bit error probability (Pe), thereby providing better performances by indoor and outdoor multipath receivers. As a result, several rake structures have been proposed in the past to reduce the number of resolvable paths that must be estimated and combined. To achieve this aim, we suggest two maximal ratio combiners based on the pulse sign separation technique, such as the pulse sign separation selective combiner (PSS-SC) and the pulse sign separation partial combiner (PSS-PC) to reduce complexity with fewer fingers and to improve the system performance. In the combiners, a comparator was added to compare the positive quantity of positive pulses and negative quantities of negative pulses to decide whether the transmitted bit was 1 or 0. ThePewas driven by simulation for multipath environments for impulse radio time-hopping binary phase shift keying (TH-BPSK) modulation, and the results were compared with those of conventional selective combiners (C-SCs) and conventional partial combiners (C-PCs).

Download Full-text

Multiple-user interference in FH-MFSK mobile radio

10.1109/eurcon.1988.11185 ◽

2003 ◽

Author(s):

M. Mizuno ◽

S. Sekizawa ◽

H. Ryuko ◽

T. Iwama ◽

T. Saruwatari ◽

...

Keyword(s):

Mobile Radio ◽

Multiple User ◽

User Interference

Download Full-text

Performance of Different OCDMA Codes with FWM and XPM Nonlinear Effects

Journal of Optical Communications ◽

10.1515/joc-2016-0093 ◽

2017 ◽

Vol 38 (3) ◽

Author(s):

Shivani Rana ◽

Amit Gupta

Keyword(s):

Phase Modulation ◽

Code Division Multiple Access ◽

Multiple Access ◽

Cross Correlation ◽

Nonlinear Effects ◽

Access System ◽

Multiple User ◽

Code Division Multiple ◽

User Interference ◽

Multiple Access System

AbstractIn this paper, 1 Gb/s non-linear optical code division multiple access system have been simulated and modeled. To reduce multiple user interference multi-diagonal (MD) code which possesses the property of having zero cross-correlation have been deployed. The MD code shows better results than Walsh-Hadamard and multi-weight code under the nonlinear effect of four-wave mixing (FWM) and cross-phase modulation (XPM). The simulation results reveal that effect of FWM reduces when MD codes are employed as compared to other codes.

Download Full-text

Spatial-Temporal-DBSCAN-Based User Clustering and Power Allocation for Sum Rate Maximization in Millimeter-Wave NOMA Systems

Symmetry ◽

10.3390/sym12111854 ◽

2020 ◽

Vol 12 (11) ◽

pp. 1854

Author(s):

Huu-Trung Hoang ◽

Quoc-Viet Pham ◽

Won-Joo Hwang

Keyword(s):

Power Allocation ◽

Millimeter Wave ◽

System Performance ◽

Clustering Algorithm ◽

State Of The Art ◽

Clustering Algorithms ◽

Real Life ◽

Multiple User ◽

User Clustering ◽

Sum Rate

The combination of millimeter-wave (mmWave) communications and non-orthogonal multiple access (NOMA) systems exploits the capability to serve multiple user devices simultaneously in one resource block. User clustering, power allocation (PA), and hybrid beamforming problems in mmWave-NOMA systems can utilize the network setting’s potential to enhance the system performance. Based on similar characteristics of the spatial distributions of users in real life, we propose a novel spatial-temporal density-based spatial clustering of applications with noise (ST-DBSCAN)-based unsupervised user clustering in order to enhance the system sum-rate. ST-DBSCAN is a state-of-the-art density-based clustering algorithm for solving spatial and non-spatial problems. Moreover, instead of symmetric PA, we propose an inter-cluster PA algorithm. Next, we apply boundary-compressed particle swarm optimization in order to reduce inter-cluster interference and enhance system performance. The simulation results reveal that our proposed solution improves the sum-rate of mmWave-NOMA-based systems when compared with that of mmWave-OMA-based systems. In addition, we compare our proposed algorithm with other benchmark user clustering algorithms in order to investigate the performance of our ST-DBSCAN-based user clustering algorithm. The results also illustrate that our proposed approach outperforms the state-of-the-art user clustering algorithms in mmWave-NOMA systems.

Download Full-text