Interference-aware Power Control Research Articles

Coordinated beamforming, interference-aware power control, and scheduling framework for 6G wireless networks

In this study, we propose a novel sum-rate enhancement framework for future 6G multi-cell multiple-input multiple-output (MIMO) uplink networks, which exploits the coordinated beamforming, power control, and user scheduling (CBPS) technique. The proposed CBPS technique not only significantly mitigates the inter-cell interference in transmit beamforming for users but also eliminates the intra-cell interference among the users in the same cell the receive beamforming at base stations (BSs). Additionally, we propose a user scheduling algorithm that selects the users whose effective channel vectors are mutually orthogonal to each other to increase the spectral efficiency and an interference-aware power control technique for users to further reduce inter-cell interference. It is worth noting that the proposed CBPS framework does not require information exchange among the BSs and operates in a non-iterative and distributed manner based on local channel state information (CSI) at both the BSs and users. Thus, it can be implemented for practical wireless systems with low complexity. Extensive simulation results show that the proposed CBPS framework significantly outperforms conventional techniques in multi-cell environments.

Efficient Interference-Aware Power Control for Wireless Networks

Interference management through power control in wireless networks has both the hidden terminal problem which induces transmission collisions, and the exposed terminal problem which blocks concurrent transmissions. Both problems are caused by the varied interference range of different links. Through observing that the nodes adopt the power control mechanism induce collisions in one scenario and miss concurrent transmission opportunities in two scenarios, this paper presents IAPC (Interference-Aware Power Control), a novel protocol to improve the network throughput from the three aspects. IAPC makes the interference range of each link covered by its CTS (Clear-To-Send) transmission through utilizing a signature detection process, so as to avoid interference. Meanwhile, it makes the CTS frame carry the transmission and reception power information of this link, according to which the neighboring node can determine a limited transmission power, trying to make itself outside the interference range of the ongoing link, so as to exploit concurrent transmissions. The signature detection range has been investigated through both experiment results and theoretical analysis, and the performance improvement of IAPC comparing with the other protocols has been shown through simulation results based on ns2.

Distributed Interference-Aware Power Control in Ultra-Dense Small Cell Networks: A Robust Mean Field Game

In ultra-dense small cell networks, interference mitigation is very important due to severe interference. Interference dynamics caused by time-varying environment should be aware and characterized when an interference-aware power control policy is designed to mitigate interference. Meanwhile, interference perception should not be naturally assumed to have complete information with certainty. Generally, it is known that a generic player will react to all the players actions and states in a power control game, which involves huge interference-related information exchange with dynamics and uncertainties. Therefore, to reduce requirements of complete information, we formulate a robust power control mean field game taking the uncertainties of both state dynamics and cost functions into consideration. To achieve the robust power control, we regard the power control problem as a game with players whose individual states are combined by a disturbance term and a Brownian motion. We derive the robust Fokker–Planck–Kolmogorov and Hamilton–Jacobi–Bellman equations, and based on which we propose the robust interference-aware power control algorithm. Simulation results demonstrate the improved performance and the robustness of the proposed algorithm.

A cross-layer design for data dissemination in vehicular ad hoc networks

Data dissemination in vehicular ad hoc networks (VANETs) has attracted researchers’ attention in recent years. However, due to high vehicle density in urban areas and increasing data volume, wireless interference seriously impairs data dissemination performance of a VANET. To alleviate the interference problem, we propose a cross-layer design to exploit both spatial and temporal reusability of wireless spectrum in VANETs. In particular, the proposed cross-layer design integrates power control in the physical layer, time division in the MAC layer and data routing in the network layer. To implement the cross-layer design, we formulate an interference-aware power-control (IAPC) problem with the objective of maximizing data throughput in a VANET. For solving the IAPC problem, an integer linear programming formulation is proposed to derive the optimal solution. In addition, an efficient heuristic algorithm, named IAPC-Solver, is proposed to achieve a near-optimal solution. Extensive simulation experiments have been conducted on a widely adopted testbed, and the experimental results illustrate that the cross-layer design together with the proposed algorithms are effective for improving data dissemination performance of a VANET.

Distributed Interference and Energy-Aware Power Control for Ultra-Dense D2D Networks: A Mean Field Game

Device-to-device (D2D) communications can enhance spectrum and energy efficiency due to direct proximity communication and frequency reuse. However, such performance enhancement is limited by mutual interference and energy availability, especially when the deployment of D2D links is ultra-dense. In this paper, we present a distributed power control method for ultra-dense D2D communications underlying cellular communications. In this power control method, in addition to the remaining battery energy of the D2D transmitter, we consider the effects of both the interference caused by the generic D2D transmitter to others and the interference from all others caused to the generic D2D receiver. We formulate a mean-field game (MFG) theoretic framework with the interference mean-field approximation. We design the cost function combining both the performance of the D2D communication and cost for transmit power at the D2D transmitter. Within the MFG framework, we derive the related Hamilton-Jacobi-Bellman and Fokker-Planck-Kolmogorov equations. Then, a novel energy and interference aware power control policy is proposed, which is based on the Lax-Friedrichs scheme and the Lagrange relaxation. The numerical results are presented to demonstrate the spectrum and energy efficiency performances of our proposed approach.

Analytical Modeling of Interference Aware Power Control for the Uplink of Heterogeneous Cellular Networks

Inter-cell interference is one of the main limiting factors in current Heterogeneous Cellular Networks (HCNs). Uplink Fractional Power Control (FPC) is a well known method that aims to cope with such limiting factor as well as to save battery live. In order to do that, the path losses associated with Mobile Terminal (MT) transmissions are partially compensated so that a lower interference is leaked towards neighboring cells. Classical FPC techniques only consider a set of parameters that depends on the own MT transmission, like desired received power at the Base Station (BS) or the path loss between the MT and its serving BS, among others. Contrary to classical FPC, in this paper we use stochastic geometry to analyze a power control mechanism that keeps the interference generated by each MT under a given threshold. We also consider a maximum transmitted power and a partial compensation of the path loss. Interestingly, our analysis reveals that such Interference Aware (IA) method can reduce the average power consumption and increase the average spectral efficiency. Additionally, the variance of the interference is reduced, thus improving the performance of Adaptive Modulation and Coding (AMC) since the interference can be better estimated at the MT.

다중 셀 상향링크 네트워크에서 신호와 간섭을 동시에 고려하는 전력 제어 및 사용자 스케쥴링

In this paper, we propose a distributed user scheduling with interference-aware power control (IAPC) to maximize signal to generating interference plus noise ratio (SGINR) in uplink multi-cell networks. Assuming that the channel reciprocity time-division duplexing (TDD) system is used, the channel state information (CSI) can be obtained at each user from pilot signals from other BSs. In the proposed scheduling, to be specific, each user reduces the transmit power if its generating interference to other BSs is larger than a predetermined threshold. Each BS selects the user with the largest SGINR among users. Simulation results show that the proposed technique significantly outperforms the existing user scheduling algorithms. It is worth noting that the proposed technique operates with distributed manner without information exchange among cells. Hence, it can be easily applied to the practical wireless systems like 3GPP LTE without significant modifications of the specification. 키워드 : 셀롤라 네트워크, 셀 간 간섭, 신호 대 발생 간섭 및 잡음비 (SGINR), 사용자 스케쥴링, 전력제어