Optimal decentralized spectral resource allocation for OFDMA downlink of femto networks via adaptive gradient vector step size approach

For the orthogonal frequency division multiple access (OFDMA) downlink of a femto network, the resource allocation scheme would aim to maximize the area spectral efficiency (ASE) subject to constraints on the radio resources per transmission interval accessible by each femtocell. An optimal resource allocation scheme for completely decentralized femtocell deployments leads to a nonlinear optimization problem because the cost function of the optimization problem is nonlinear. In this paper, an adaptive gradient vector step size approach is proposed for finding the optimal solution of the optimization problem. Computer numerical simulation results show that our proposed method is more efficient than existing exhaustive search methods

Dynamic frequency reuse: a method for interference mitigation in OFDMA Based LTE-A Networks

Spectrum scarcity is one of the most discussed restraining aspects in wireless communication system. To solve this issue Frequency Reuse (FR) concept is introduced. It is a promising development to fulfil the requirement of Long Term Evolution Advanced (LET-A). With the introduction of FR comes the problem of Inter Cell Interference as the neighboring eNodeBs (eNB) which uses the same frequency band that will act as an interference source. In this paper, a Dynamic Frequency Reuse (DFR) method is anticipated. Continuous optimization of resource allocation of each cell is considered in this method. The important focus of the paper is to expand the capacity of the users placed in cell edge areas by reducing out of cell interference. Simulation has been done to prove that the proposed scheme leads to efficient resource management

Decentralized spectral resource allocation for OFDMA downlink of coexisting macro/femto networks using filled function method

For an orthogonal frequency division multiple access (OFDMA) downlink of a spectrally coexisting macro and femto network, a resource allocation scheme would aim to maximize the area spectral efficiency (ASE) subject to constraints on the radio resources per transmission interval accessible by each femtocell. An optimal resource allocation scheme for completely decentralized deployments leads however to a nonconvex optimization problem. In this paper, a filled function method is employed to find the global maximum of the optimization problem. Simulation results show that our proposed method is efficient and effective

Power Control in Massive MIMO with Dynamic User Population

This paper considers the problem of power control in Massive MIMO systems taking into account the pilot contamination issue and the arrivals and departures of users in the network. Contrary to most of existing work in MIMO systems that focuses on the physical layer with fixed number of users, we consider in this work that the users arrive dynamically and leave the network once they are served. We provide a power control strategy, having a polynomial complexity, and prove that this policy stabilizes the network whenever possible. We then provide a distributed implementation of the power control policy requiring low information exchange between the BSs and show that it achieves the same stability region as the centralized policy.Comment: conference paper, submitte

Quality of Service Improvement in Femto based Cellular Networks

A cellular network serve the high service demands of the indoor users it is very expensive to obtain macrocell coverage which results in requirement of new methods to solve problem of high capacity indoor coverage femto cell is one of the solutions. Deployment of femto cell networks embedded into macro cell coverage improves the coverage, capacity and quality of service in indoor environments. Due to its ad-hoc nature, the information about its density and location is not known a-priori. As femtos and macros share the same licensed spectrum, interference is one of the major problems observed and has to be mitigated. In this paper two existing channel allocation schemes such as opportunistic channel allocation scheme and orthogonal channel allocation scheme are discussed and their performance is compared to the proposed Max-SINR scheme. To reduce the interference further a self-organized and intelligent resource allocation is also proposed .Parameter such as average SINR experienced by each femto user is calculated by varying the percentage of active Femto cells in a network. Simulation results are carryout using MATLAB

Quality of Service Improvement in Femto based Cellular Networks

A cellular network serve the high service demands of the indoor users it is very expensive to obtain macrocell coverage which results in requirement of new methods to solve problem of high capacity indoor coverage femto cell is one of the solutions. Deployment of femto cell networks embedded into macro cell coverage improves the coverage, capacity and quality of service in indoor environments. Due to its ad-hoc nature, the information about its density and location is not known a-priori. As femtos and macros share the same licensed spectrum, interference is one of the major problems observed and has to be mitigated. In this paper two existing channel allocation schemes such as opportunistic channel allocation scheme and orthogonal channel allocation scheme are discussed and their performance is compared to the proposed Max-SINR scheme. To reduce the interference further a self-organized and intelligent resource allocation is also proposed .Parameter such as average SINR experienced by each femto user is calculated by varying the percentage of active Femto cells in a network. Simulation results are carryout using MATLAB