Temat: power allocation - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Effect of unequal power allocation in turbo coded multi-route multi-hop networks
Autorzy:: Wada, T.
Jamalipour, A.
Ohuchi, K.
Okada, H.
Saito, M.
Tematy:: multi-route transmissions
turbo codes
power allocation; Pokaż więcej
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/309168.pdf Link otwiera się w nowym oknie
Opis:: Multi-hop ad hoc networks are promising candidates for next generation mobile communications. They have sufficient channel capacity to achieve high data rate transmission for large number of users. One advantage of multi-hop networks is to realize multi-route transmissions. Since information bit streams can be transmitted over multiple routes, we can obtain route diversity effect. In order to enhance the route diversity effect, we usually introduce forward error correction schemes. Turbo coding is one of suitable coding methods for multi-hop networks. The turbo encoder generates one message stream and two parity streams whilst the message stream is more important than the parity streams for achieving reliable communications. Thus an unequal power allocation to the message and parity streams could be effective in improving the performance. In this paper, the effect of unequal power allocation for turbo coded multi-hop networks is investigated. Assuming the channel as additive white Gaussian and binary symmetric, we will show considerable performance improvement by unequal power allocation in terms of the bit error rate performance in multi-route multi-hop networks.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Improved Water-Filling Power Allocation for Energy-Efficient Massive MIMO Downlink Transmissions
Autorzy:: Noor Shahida, M. K.
Nordin, R.
Insmail, M.
Tematy:: energy efficiency
Massive MIMO
power allocation
spectral efficiency; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/227000.pdf Link otwiera się w nowym oknie
Opis:: Energy Efficiency (EE) is becoming increasingly important for wireless communications and has caught more attention due to steadily rising energy costs and environmental concerns. Recently, a new network architecture known as Massive Multiple-Input Multiple-Output (MIMO) has been proposed with the remarkable potential to achieve huge gains in EE with simple linear processing. In this paper, a power allocation algorithm is proposed for EE to achieve the optimal EE in Massive MIMO. Based on the simplified expression, we develop a new algorithm to compute the optimal power allocation algorithm and it has been compared with the existing scheme from the previous literature. An improved water filling algorithm is proposed and embedded in the power allocation algorithm to maximize EE and Spectral Efficiency (SE). The numerical analysis of the simulation results indicates an improvement of 40% in EE and 50% in SE at the downlink transmission, compared to the other existing schemes. Furthermore, the results revealed that SE does not influence the EE enhancement after using the proposed algorithm as the number of Massive MIMO antenna at the Base Station (BS) increases.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Power Allocation for Energy-Harvesting-based Fading Cognitive Multiple Access Channels : with or without Successive Interference Cancellation
Autorzy:: Li, Q.
Xu, D.
Tematy:: cognitive radio
power allocation
multiple access channels
energy harvesting; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/963855.pdf Link otwiera się w nowym oknie
Opis:: This paper considers a fading cognitive multiple access channel (CMAC), where multiple secondary users (SUs), who share the spectrum with a primary user (PU), transmit to a cognitive base station (CBS). A power station is assumed to harvest energy from the nature and then provide power to the SUs. We investigate the power allocation problems for such a CMAC to maximize the SU sum rate under the interference power constraint, the sum transmit power constraint and the peak transmit power constraint of each individual SU. In particular, two scenarios are considered: with successive interference cancellation (SIC) and without SIC. For the first scenario, the optimal power allocation algorithm is derived. For the second scenario, a heuristic algorithm is proposed. We show that the proposed algorithm with SIC outperforms the algorithm without SIC in terms of the SU sum rate, while the algorithm without SIC outperforms the algorithm with SIC in terms of the number of admitted SUs for a high sum transmit power limit and a low peak transmit power limit of each individual SU.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Energy Efficiency Optimization by Spectral Efficiency Maximization in 5G Networks
Autorzy:: Krasniqi, B.
Rexha, B.
Maloku, B.
Tematy:: energy efficiency
5G
radio resources
power allocation
optimization convexity; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/226636.pdf Link otwiera się w nowym oknie
Opis:: Energy and spectral efficiency are the main challenges in 5th generation of mobile cellular networks. In this paper, we propose an optimization algorithm to optimize the energy efficiency by maximizing the spectral efficiency. Our simulation results show a significant increase in terms of spectral efficiency as well as energy efficiency whenever the mobile user is connected to a low power indoor base station. By applying the proposed algorithm, we show the network performance improvements up to 9 bit/s/Hz in spectral efficiency and 20 Gbit/Joule increase in energy efficiency for the mobile user served by the indoor base station rather than by the outdoor base station.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: OFDM for Cognitive Radio Systems : Novel Power Allocation and Bit Loading Algorithms
Autorzy:: Razmi, Shirin
Parhizgar, Naser
Tematy:: cognitive radio
OFDM
interference constraints
power allocation
adaptive modulation
bit loading; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/227256.pdf Link otwiera się w nowym oknie
Opis:: A novel method to improve the performance of the frequency band is cognitive radio that was introduced in 1999. Due to a lot of advantages of the OFDM, adaptive OFDM method, this technique is used in cognitive radio (CR) systems, widely. In adaptive OFDM, transmission rate and power of subcarriers are allocated based on the channel variations to improve the system performance. This paper investigates adaptive resource allocation in the CR systems that are used OFDM technique to transmit data. The aim of this paper is to maximize the achievable transmission rate for the CR system by considering the interference constraint. Although secondary users can be aware form channel information between each other, but in some wireless standards, it is impossible for secondary user to be aware from channel information between itself and a primary user. Therefore, due to practical limitation, statistical interference channel is considered in this paper. This paper introduces a novel suboptimal power allocation algorithm. Also, this paper introduces a novel bit loading algorithm. In the numerical results sections, the performance of our algorithm is compared by optimal and conventional algorithms. Numerical results indicate our algorithm has better performance than conventional algorithms while its complexity is less than optimal algorithm.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Modulation-Mode Assignment for SVD-assisted Downlink Multiuser MIMO Transmission Schemes with Iterative Detection
Autorzy:: Ahrens, A.
Benavente-Peces, C.
Tematy:: multiple-input multiple-output system
singular value decomposition
bit allocation
power allocation
wireless transmission
multiuser transmission; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/226541.pdf Link otwiera się w nowym oknie
Opis:: Since the capacity of multiple-input multiple-output (MIMO) systems increases linearly with the minimum number of antennas at both, the transmitter as well as the receiver side, MIMO systems have attracted a lot of attention for both frequency and non-frequency selective channels and reached a state of maturity. By contrast, MIMO-aided multiple-user systems require substantial further research. In comparison to zero-forcing (ZF) multiuser transmission techniques, where all users are treated jointly, the investigated singular value decomposition (SVD) assisted DL multiuser MIMO solution takes the individual user's channel characteristics into account. In analogy to bit-interleaved coded irregular modulation, we introduce a MIMO-BICM scheme, where different user-specific signal constellations and mapping arrangement were used within a single codeword. Extrinsic information transfer (EXIT) charts are used for analyzing and optimizing the convergence behaviour of the iterative demapping and decoding. Our results show that in order to achieve the best bit-error rate, not necessarily all user-specific MIMO layers have to be activated.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Performance Enhancement of Cooperative MIMO-NOMA Systems Over Sub-6 GHz and mmWave Bands
Autorzy:: Saleh, Ahmed A.
Ahmed, Mohamad A.
Tematy:: error probability
MIMO
mmWave
NOMA
out-age probability
power allocation factor
successive-interference cancellation (SIC; Pokaż więcej
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/24200732.pdf Link otwiera się w nowym oknie
Opis:: In this paper, two radio links with diﬀerent frequency bands are considered for base stations (BS) serving users via decode-and-forward (DF) cooperative relays. Backhaul and access links are proposed with sub-6 GHz and millimeter wave (mmWave) bands, respectively. Non-orthogonal multiple access (NOMA) is employed in the backhaul link to simultaneously transmit a superposed signal in the power domain, using the same band. The superposed signals, containing two signals that diﬀer in terms of power allocation factors (PAFs), are designed for two selected DF relays in the BS. The two relays are chosen from several relays to be serviced by the BS based on a pairing algorithm that depends on diﬀerent users’ circumstances. The furthest DF relay detects the incoming NOMA signal directly, while the nearest one applies successive interference cancellation (SIC) before extracting its signal. Each DF relay forwards the detected signals toward their intended users over mmWave channels. Three performance metrics are utilized to evaluate the system’s performance: outage probability, achievable throughput, and bit error rate. Comparisons between two mmWave bands in the access link (28 and 73 GHz) are made to demonstrate the superiority of the 28 GHz band in terms of the three performance-related metrics.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Downlink power allocation in Delta-OMA (D-OMA) 6G networks
Autorzy:: Martyna, Jerzy
Wydawca:: Springer
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

Inne

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Skocz do pozycji: 9.

Tytuł:: Alokacja zasobów w sieciach femtokomórkowych
Resource allocation in femtocell networks
Autorzy:: Prusaczyk, Emil
Opis:: Systemy femtokomórkowe to realizacje udostępniania zasobów radiowych urządzeniom mobilnym. Są one odpowiedzią na wzrastające wymagania użytkowników telefonii komórkowej oraz na ograniczenia zasięgu technologii makrokomórkowej wewnątrz budynków. Ponieważ femtokomórki są tanie i nieintruzyjne, są one atrakcyjnym rozwiązaniem, ale ich integracja z istniejącą architekturą nie jest trywialna. Kłopotliwy jest również problem alokacji zasobów w sieciach femtokomórkowych, czyli przydział mocy stacjom bazowym oraz alokacja częstotliwości użytkownikom. W celu maksymalizacji wykorzystania dostępnego widma oraz minimalizacji powstałej interferencji, można zastosować różne dostępne schematy. W tej pracy zaprezentowano architekturę sieci femtokomórkowych oraz ich dostosowanie do obecnych standardów telefonii komórkowej. Przedstawione zostały także schematy alokacji zasobów, zarówno nieskomplikowane rozwiązania, jak i metody oparte o podejścia heurystyczne. Objaśniono dwa algorytmy: algorytm optymalizacji rojem cząstek oraz algorytm genetyczny. Implementacja pierwszego z nich posłużyła stworzeniu symulacji w środowisku MATLAB, która obrazuje przydział zasobów w przykładowej sieci femtokomórkowej oraz porównuje dwa warianty algorytmu w zakresie przepustowości femtokomórkowych stacji bazowych.
Femtocell systems are implementations of providing telecommunication services to mobile devices. They are an answer to the increasing demands of mobile phone users and to the limitations of macrocell indoor coverage. Because femtocells are cheap and unintrusive , they are an attractive solution, but their integration into the existing architecture is not trivial. Resource allocation in femtocell networks, meaning power assignment to base stations and frequency allocation to users, is also problematic. In order to maximize utilization of the available spectrum and to minimize the resulting interference, a number of available schemes can be applied. In this paper, the architecture of femtocell networks has been presented, as well as their adaptation to current mobile telephony standards. Resource allocation techniques have also been demonstrated, both simple solutions as well as approaches based on heuristic methods. Two algorithms have been suggested: particle swarm optimization and genetic algorithm. An implementation of the former has served in creating a simulation in MATLAB, which illustrates resource allocation in an example femtocell network, and compares two variants of the algorithm in terms of femtocell base station throughput.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 10.

Tytuł:: Dynamic electric vehicles charging load allocation strategy for residential area
Autorzy:: Wang, Y.
Ma, X.
Wang, F.
Hou, X.
Sun, H.
Zheng, K.
Tematy:: electric vehicles
charging power management
allocation strategy
priority assessment; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/140939.pdf Link otwiera się w nowym oknie
Opis:: A large amount of electric vehicles (EVs) charging load will bring significant impact to the power system. An appropriate resource allocation strategy is required for securing the power system safety and satisfying EVs charging demand. This paper proposed a power coordination allocation strategy of EVs’ in distribution systems. The strategy divides the allocation into two stages. The first stage is based on scores assigned to EVs through an entropy method, whereas the second stage allocates energy according to EV’s state of charge. The charging power is delivered in order to maximize EV users’ satisfaction and fairness without violation of grid constraints. Simulation on a typical power-limited residential distribution network proves the effectiveness of the strategy. The analysis results indicate that compared with traditional methods, EVs, which have higher charging requirement and shorter available time will get more energy delivered than others. The root-mean-square-error (RMSE) and standard-deviation (SD) results prove the effectiveness of the methodology for improving the balance of power delivery.
Dostawca treści:: Biblioteka Nauki

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