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In this paper, two novel energy efficient resource allocation schemes are proposed for beyond next generation mobile networks. The schemes take into account the clustering capability of base stations before assigning users to the base stations. A topology management scheme that adjusts the number of active base stations in accordance with the traffic load and also responds to QoS deterioration is...
In this paper, the influence of feedback channel delay on system throughput of the cooperative multi-cell system with adaptive beamforming selection is discussed. On the one hand, multi-cell cooperative processing (MCP) has the potential to boost spectral efficiency and improve fairness among users. However, the traditional centralized multi-cell cooperative scheme, where a central processing unit...
As a promising communication paradigm, Cognitive Radio Networks (CRNs) have paved a road for Secondary Users (SUs) to opportunistically exploit unused licensed spectrum without causing unacceptable interference to Primary Users (PUs). In this paper, we study the distributed data collection problem for asynchronous CRNs, which has not been addressed before. First, we study the Proper Carrier-sensing...
Device-to-Device (D2D) communication underlaying cellular network is considered to be a promising resource reuse technique, and it is basically developed for lots of local services. Considering the differences of the quality of services (QoS) between cellular and D2D users, the resource allocation scheme for D2D should flexibly allocate resource for D2D, rather than limiting one D2D user to share...
In this paper, we consider the challenging problem of power allocation in interfering wireless networks with services having stringent delay constraints. The objective is to allocate optimally the power to each user, take advantage of the time diversity of the time varying channel and satisfy the delay constraints of the services. To this end, we model the bit rate dynamics of the users as a linear...
In this paper, the performance of parallel interference cancellation (PIC) multiuser detector in orthogonal frequency division multiple access (OFDMA) mobile communication systems is investigated. In multiuser systems, the multi-user interference (MUI) degraded the system performance, especially in near-far effect environments. The PIC scheme is proposed to reduce the MUIs and to improve the bit error...
Base station cooperation requires knowledge of the users' channel state information (CSI) at the transmitter side to manage co-channel interference. Users in a multicell cooperative system have to feedback the CSI of desired and interfering channels using finite-bandwidth links. Hence, the available feedback resources need to be partitioned efficiently between the multiple channels. In this paper,...
A novel de-centralized dynamic inter-cell interference coordination (ICIC) method, which can change cell-edge bands dynamically by using an X2 interface and can be applied to current downlink long-term evolution (LTE) systems, is proposed. This dynamic ICIC method can autonomously optimize fractional frequency reuse (FFR) parameters and thus increase throughput. In addition, it works well even in...
Cooperative detection involving neighboring base stations is a promising means to increase spectral efficiency in the uplink of cellular systems. To fully utilize the new degrees of freedom that come with base station cooperation, it is essential that a joint scheduler is aware of the interference conditions in all participating cells in order to perform efficient resource and rate allocation. However,...
In this paper, we propose a distributive queue-aware intra-cell user scheduling and inter-cell interference (ICI) management control design for a delay-optimal cellular downlink system with M base stations(BSs). Each BS has K downlink queues for K users respectively with heterogeneous arrivals and delay requirements. The ICI management control is adaptive to joint queue state information (QSI) over...
Cognitive radio in network core devices such as basestations is being considered as a spectrum management solution for future society's communication demands. Aside from new resource allocation algorithms, efficient inter- and intra-protocol processing should be considered. We propose an opportunistic cross layer architecture called COmmon Layer Architecture (COLA) for information exchange between...
Under the background of TDD mode and LTE-Advanced scene, in this paper, we combine physical network coding with relay technology in order to make physical network coding-decode and forward (PNC-DF) together with physical network coding-amplify and forward (PNC-AF) transfer mode can be used to improve network throughput by using interference. Because of the ability to listen to the multi-user relay...
In multicell cooperation, knowledge of the users' channel state information (CSI) at the base stations can be used to improve sum-rates and reduce outages. Users estimate and feedback CSI of the desired and multiple interfering channels in cooperation-based systems. Existing multicell limited feedback techniques are memoryless quantization approaches, which result in large feedback overhead. In this...
The role of uplink power control is to suppress interference. Power control refers to set output power levels of transmitters, base stations in the downlink and User Equipment (UE) in the uplink. In this paper the performance of 3GPP Long Term Evolution (LTE) closed loop power control combined with fractional path loss compensation factor is evaluated by simulating the effects of open loop error,...
This paper investigates stability and robustness of a gradient-type power control algorithm for multicell CDMA wireless communication networks in the presence of time-delays and disturbances. The time-delays in individual communication channels between mobiles and base stations are allowed to take place independently. The disturbances represent power noises, unmodeled secondary interference and variation...
Limited feedback beamforming improves link reliability with a small amount of feedback from the receiver to the transmitter. The performance of such a closed loop MIMO system is unknown in interference limited cellular environments, when the base stations have limited or no coordination. This paper establishes the degradation in throughput due to uncoordinated other cell interference and delay on...
Base station cooperation transmission, which is also known as coordinated multi-point (CoMP) transmission, is a promising technique to improve system spectrum efficiency in cellular networks, especially for multiple antenna systems. However, the performance gain is significant only when cooperative base stations can gather channel state information (CSI) from all their serving users and can share...
The different propagation times due to the distinct distance between the BSs and MSs result in inter-cell asynchronous interference, which severely destroy system performance. How to mitigate inter-cell asynchronous interference by making use of SLNR precoding is the key to this paper. Firstly, a framework of Cooperative Base Station Systems (Co-BS) was developed and the delay between the cells was...
In this paper, the problem of resource allocation in IS-856 uplink in the presence of time-delay is studied. A set of nonlinear adaptive controllers are designed to stabilize the wireless network and use the system resources efficiently. The controllers obtained are then modified properly to retain network stability and performance in the presence of time-delay. Simulation results are presented to...
In the uplink of OFDMA (Orthogonal Frequency Division Multiple Access) based M-WiMAX (Mobile-Worldwide Interoperability for Microwave Access) system, linear phase shift is caused by signals transmitted from multiuser with different delay time and thus, MAI (Multiple Access Interference) occurs. MAI degrades the performance of ranging code detection and delay time estimation in the uplink. Therefore,...
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