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One major topic of research into SON technology is the coordination of SON use cases. Network operators expect a coordinated handling of the parameter and configuration changes submitted to the operating network by closed-loop SON use case implementations. Beside a published conceptual framework, SON coordination has already been treated in the literature, especially regarding the mobility load balancing...
In this paper, we propose a new transmission scheme with two relay stations and phase feedback channels between the relays and the destination node. The exploiting of a preprocessor use in the relay stations is managed to achieve a full diversity order and also an array gain at the destination node. A phase feedback investigation for the proposed scheme is presented assuming quasi-static flat Rayleigh...
WiMAX is the very well known 802.16 technology certified by the WiMAX forum. However, it is not largely known that the IEEE 802.16 standard foresees an option to use the technology on the license-free 5 GHz band. For such a use, the EIRP requirements for the 5 GHz band must be respected. The use of WiMAX technology in that band may be an interesting option for wireless backhauling and wireless mesh...
We present in this paper a software implementation of a cognitive radio (CR) communication based on long term evolution-time division duplex (LTE-TDD) channel reciprocity. We study the problem of calibration and beamforming design for a CR system in which a multiple-input single-output (MISO) secondary link, wants to opportunistically communicate without harming the primary SISO system. Specifically,...
In this work, we analyze the performance of cooperative relay based energy detection in cognitive radio. The two hop cognitive relay is considered in independent and identically distributed (i.i.d.) Nakagami-m fading channels. An energy detector is employed at the fusion center where the lower bound average detection probability is obtained by averaging the alternative Marcum-Q function over probability...
This work1 deals with interference alignment (IA) in a K-users MIMO interference channel with only incomplete Channel State Information at the Transmitters (CSIT). Incompleteness of CSIT is defined by the perfect knowledge of only a sub-matrix of the global channel matrix. Additionally, each Transmitter (TX) may have different incomplete CSIT. Most IA techniques are developed under a full (complete)...
Layered and cooperative elements such as femto-cells and relays can improve performance or energy efficiency in mobile networks; however, they consume energy per se and their durations in operational state must therefore be minimised. This paper investigates the use of relays in WiMAX network deployments and concentrates on the cost/revenue performance and energy efficiency trade-off in such cases...
Interference alignment is a promising approach to handle the interference in mobile radio networks especially at high SNR. In the present paper, the interference alignment is achieved using a number of MIMO relays in a scenario with K single antenna node pairs. A two-phase transmission scheme is considered assuming the channel to be constant during the transmission phases. Firstly, the source nodes...
Coverage optimisation is an important self-organising capability that operators would like to have in LTE networks. This paper applies a Reinforcement Learning (RL) based Sparse Sampling algorithm for the self-optimisation of coverage through antenna tilting. This algorithm is better than supervised learning and Q-learning based algorithms as it has the ability to adapt to network environments without...
We consider the minimization of the energy per bit (or, equivalently, the maximization of the energy efficiency) in a multiple-input single-output (MISO) broadcast channel with rate balancing constraints, i.e., in a multiuser system where certain fixed ratios between the rates of the various users have to be kept. This paper deals with the practically relevant case where the transmit strategy is restricted...
The emerging IEEE 802.11ac standard introduces spatial division multiplexing access, in its downlink version, to the wireless local access world. Through this multi-user multiple input multiple output (MU-MIMO) technique the access point (AP) can simultaneously transmit multiple independent groups of streams to different stations. The consequent precoding requires precise channel knowledge and thus...
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