Carrier sense using subcarrier-multiplexed signaling for optical frequency division multiple access

1997 ◽  
Vol 15 (5) ◽  
pp. 758-765 ◽  
Author(s):  
K. Kitayama
Keyword(s):  
Multiple Access ◽  
Optical Frequency ◽  
Frequency Division ◽  
Carrier Sense

Study of Power Control in CDMA System on the basis of optimization Technique

2017 ◽  
Vol 7 (8) ◽  
pp. 126
Author(s):  
. Geetanjli
Keyword(s):  
Power Control ◽  
Multiple Access ◽  
Optimization Technique ◽  
System Optimization ◽  
Base Station ◽  
Particle Swarm Algorithm ◽  
Cdma System ◽  
Frequency Division ◽  
Cdma Systems ◽  
Time Division

The power control in CDMA systems, grant numerous users to share resources of the system uniformly between each other, leading to expand capacity. With convenient power control, capacity of CDMA system is immense in contrast of frequency division multiple access (FDMA) and time division multiple access (TDMA). If power control is not achieved numerous problems such as the near-far effect will start to monopolize and consequently will reduce the capacity of the CDMA system. However, when the power control in CDMA systems is implemented, it allows numerous users to share resources of the system uniformly between themselves, leading to increased capacity For power control in CDMA system optimization algorithms i.e. genetic algorithm & particle swarm algorithm can be used which regulate a convenient power vector. These power vector or power levels are dogged at the base station and announce to mobile units to alter their transmitting power in accordance to these levels. The performances of the algorithms are inspected through both analysis and computer simulations, and compared with well-known algorithms from the literature.

scholarly journals Analysis of Dual-Band Direction of Arrival Estimation in Multipath Scenarios

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1236
Author(s):  
Alessandro Cidronali ◽  
Edoardo Ciervo ◽  
Giovanni Collodi ◽  
Stefano Maddio ◽  
Marco Passafiume ◽  
...  
Keyword(s):  
Multiple Access ◽  
Direction Of Arrival ◽  
Doa Estimation ◽  
Dual Band ◽  
Second Step ◽  
Frequency Division ◽  
Simulation Environment ◽  
Full Wave ◽  
Wide Range ◽  
Localization Systems

The present paper analyzes the performance of localization systems, based on dual-band Direction of Arrival (DoA) approach, in multi-path affected scenarios. The implemented DoA estimation, which belongs to the so-called Space and Frequency Division Multiple Access (SFDMA) technique, takes advantage of the use of two uncorrelated communication carrier frequencies, as already demonstrated by the authors. Starting from these results, this paper provides, first, the methodology followed to describe the localization system in the proposed simulation environment, and, as a second step, describes how multi-path effects may be taken into account through a set of full-wave simulations. The latter follows an approach based on the two-ray model. The validation of the proposed approach is demonstrated by simulations over a wide range of virtual scenarios. The analysis of the results highlights the ability of the proposed approach to describe multi-path effects and confirms enhancements in DoA estimation as experimentally evaluated by the same authors. To further assess the performance of the aforementioned simulation environment, a comparison between simulated and measured results was carried out, confirming the capability to predict DoA performance.

Indoor MIMO VLC systems using optical orthogonal frequency division multiple access

2021 ◽  
Vol 485 ◽  
pp. 126728
Author(s):  
Jie Lian ◽  
Yan Gao ◽  
Peng Wu ◽  
Guolei Zhu ◽  
Yingmin Wang
Keyword(s):  
Multiple Access ◽  
Frequency Division

scholarly journals An energy-efficient and elastic optical multiple access system based on coherent interleaved frequency division multiple access

2013 ◽  
Vol 21 (10) ◽  
pp. 12282 ◽  
Author(s):  
Yuki Yoshida ◽  
Akihiro Maruta ◽  
Kenji Ishii ◽  
Yuji Akiyama ◽  
Tsuyoshi Yoshida ◽  
...  
Keyword(s):  
Energy Efficient ◽  
Multiple Access ◽  
Frequency Division ◽  
Access System ◽  
Multiple Access System
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