Throughput maximization for UAV-assisted wireless powered D2D communication networks with a hybrid time division duplex/frequency division duplex scheme

2021 ◽  
Vol 27 (3) ◽  
pp. 2147-2157
Author(s):  
Ming Lei ◽  
Xingjun Zhang ◽  
Bocheng Yu ◽  
Scott Fowler ◽  
Bin Yu
Keyword(s):  
Communication Networks ◽  
D2d Communication ◽  
Throughput Maximization ◽  
Frequency Division ◽  
Time Division Duplex ◽  
Time Division

scholarly journals Desain dan Implementasi Duplekser dengan Metoda Pseudo-Interdigital untuk Uplink dan Downlink LTE

2016 ◽  
Vol 13 (2) ◽  
pp. 73
Author(s):  
Enceng Sulaeman ◽  
Yaya Sulaeman ◽  
Asep Yudi Hercuadi
Keyword(s):  
Insertion Loss ◽  
Return Loss ◽  
Bandpass Filter ◽  
Long Term Evolution ◽  
Full Duplex ◽  
Frequency Division ◽  
Time Division Duplex ◽  
Term Evolution ◽  
Time Division

Duplekser merupakan perangkat yang dapat mengisolasi receiver dari transmitter saat keduanya saling berbagi antena yang sama, digunakan agar komunikasi bisa berjalan secara full duplex. Ada dua metode transmisi duplex yaitu frequency division duplex (FDD) dan time division duplex (TDD). FDD merupakan teknik duplex yang menggunakan dua frekuensi yang berbeda untuk melakukan komunikasi dalam dua arah, sedangkan TDD menggunakan frekuensi tunggal dan frekuensi tersebut digunakan oleh semua kanal untuk melakukan pengiriman dan penerimaan data. Gabungan dua bandpass filter dengan metoda pseudo-interdigital untuk aplikasi LTE (long term evolution). Metode ini lebih unggul dibandingkan duplekser dengan metoda hybrid. Duplekser bekerja pada FDD LTE band ke-7 yaitu frekuensi uplink 2500-2570 MHz dan downlink 2620-2690 MHz. Dari hasil pengukuran diperoleh sebagai berikut: nilai frekuensi center pada uplink 2639 MHz dan pada downlink 2659 MHz, insertion loss pada uplink 1,561 dB dan downlink 1,74 dB, bandwidth ±70 MHz, isolasi 23,03 dB, serta nilai return loss 23,5 dB pada uplink dan downlink 23,45 dB.

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.

Throughput Maximization of Wireless-Powered Communication Networks: An Energy Threshold Approach

2021 ◽  
pp. 1-1
Author(s):  
Kechen Zheng ◽  
Xiaoying Liu ◽  
Biao Wang ◽  
Haifeng Zheng ◽  
Kaikai Chi ◽  
...  
Keyword(s):  
Communication Networks ◽  
Energy Threshold ◽  
Throughput Maximization ◽  
Threshold Approach

Centralized Dynamic-Time Division Duplex Utilizing Interference Alignment

2021 ◽  
pp. 1-1
Author(s):  
Mojtaba Ghermezcheshmeh ◽  
Mohsen Mohammadkhani Razlighi ◽  
Vahid Shah-Mansouri ◽  
Nikola Zlatanov
Keyword(s):  
Interference Alignment ◽  
Time Division Duplex ◽  
Dynamic Time ◽  
Time Division

scholarly journals Joint power allocation and subcarrier assignment for device to device in 5G time division duplex networks

2018 ◽  
Vol 14 (11) ◽  
pp. 155014771881109 ◽  
Author(s):  
Pan Zhao ◽  
Lei Feng ◽  
Peng Yu ◽  
Wenjing Li ◽  
Xuesong Qiu
Keyword(s):  
Quality Of Service ◽  
Power Allocation ◽  
Base Station ◽  
Joint Power ◽  
Time Division Duplex ◽  
Device To Device ◽  
Minlp Problem ◽  
Device To Device Communication ◽  
Time Division

The explosive demands for mobile broadband service bring a major challenge to 5G wireless networks. Device-to-device communication, adopting side links for user-direct communication, is regarded as a main technical source for offloading large volume of mobile traffic from cellular base station. This article investigates the joint power and subcarrier allocation scheme for device-to-device communication in 5G time division duplex systems. In time division duplex system, instead of utilizing an exclusive portion of the precious cellular spectrum, device-to-device pairs reuse the subcarriers occupied by cellular users, thus producing harmful interference to cellular users in both uplink and downlink communication, and strongly limiting the spectrum efficiency of the system. To this end, we focus on the maximization of device-to-device throughput while guaranteeing both uplink and downlink channel quality of service of cellular users as well as device-to-device pairs. The problem is formulated as a mixed integer non-linear programming (MINLP) problem. To make it tractable, we separate the original MINLP problem into two sub problems: power allocation and sub-carrier reusing. The former is to develop optimal power allocation for each device-to-device pair and each cellular user, with the constraints of maximum power and quality of service. It is solved by geometric programming technique in convex optimization method. The latter is derived as a one-to-many matching problem for scheduling multiple subcarriers occupied by cellulars to device-to-device pairs. It is solved by Hungarian method. Simulation results show that the proposed scheme significantly improves system capacity of the device-to-device underlay network, with quality of service of both device-to-device users and cellular users guaranteed.

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