A Quasi-Perfect Resource Allocation Scheme for Optimizing the Performance of Cell-Edge Users in FFR-

A Quasi-Perfect Resource Allocation Scheme for Optimizing the Performance of Cell-Edge Users in FFR-Aided LTE-A Multi cell Networks

Abstract: A quasi-perfect resource allocation scheme for optimizing the performance of celledge users (CEUs) in FFR-aided LTE-A multi cell networks (Q-PRAFFR) is proposed, which splits cell-edge region, cell-edge bandwidth and CEUs into six parts and allocates resource to CEUs with the predefined resource allocation priority. Therefore, the better performance for inter cell interference (ICI) coordination is achieved which results from the more uniform distance distribution among the CEUs allocated the same bandwidth in different cells. Numerical results show that the outage probability of the fifth-percentile users is dropped by around 70% and the cell throughput is increased by about 10% compared with the state-ofthe-art FFR technology.

Existing system: The main contributions of this letter are as follows. A quasi-perfect resource allocation scheme for optimizing the performance of CEUs in FFR-aided LTE-A multi cell networks (Q-PRAFFR) is presented which splits cell-edge region, cell edge bandwidth and CEUs into six parts and allocates resource to CEUs with the

predefined resource allocation priority that leads to the more uniform distance distribution among the CEUs allocated the same bandwidth in different cells.

Consequently, it mitigates the ICI, decreases the outage probability of the CEUs and increases the overall data rate compared with the state-of-the-art FFR technology.

Proposed system: The reference improved the energy efficiency of FFR by optimizing the distributed antenna system. The authors in [5] investigated FFR scheme in higher order sectorization deployments and proposed a new spectrum efficiency-based users classification method. In, a dynamic FFR was proposed to increase the trunking gain, while satisfying minimum data rate requirement. The soft frequency reuse (SFR) scheme divides the whole bandwidth into three equal parts and the two parts are used for the cell-center users (CCUs) whereas another part for the CEUs in a way that no adjacent sectors can access to the same bandwidth for their CEUs. By transmitting higher power for CEUs than for CCUs, SFR can mitigate ICI to a tolerable level. Adaptive SFR algorithm (ASFR) dynamically allocates subcarriers and power to achieve the improvement of system capacity. A multi-level soft frequency reuse (ML-SFR) was presented to achieve a better interference pattern further and improve the cell throughput compared with two-level SFR. Advantages: The distance between arbitrary two adjacent CEUs allocated the same bandwidth is constant value 3RH. If there exist six CEUs interfering with one CEU in its adjacent six cells, they are distributed on the six vertices of the regular hexagon centered on this CEU. The transmit antennas of the CEUs are Omni directional.

Moreover, for each CEU, the number of CEUs interfering with it is theoretically equal and they are equally spaced when PRA is employed in the networks. In other words, each CEU has a similar interference CEUs distribution which results in their similar ICI. Disadvantages:

The main contributions of this letter are as follows. A quasi-perfect resource allocation scheme for optimizing the performance of CEUs in FFR-aided LTE-A multi cell networks (Q-PRAFFR) is presented which splits cell-edge region, cell edge bandwidth and CEUs into six parts and allocates resource to CEUs with the predefined resource allocation priority that leads to the more uniform distance distribution among the CEUs allocated the same bandwidth in different cells.

Consequently, it mitigates the ICI, decreases the outage probability of the CEUs and increases the overall data rate compared with the state-of-the-art FFR technology.

Modules: Inter – cell interference: FREQUENCY reuse technique has become a powerful mechanism for inter-cell interference (ICI) coordination that has been already implemented by the emerging LTE-A cellular networks as an efficient way to increase the throughput performance perceived by cell-edge users (CEUs). It has been extensively explored under the subject of mitigating the ICI. The reference improved the energy efficiency of FFR by optimizing the distributed antenna system. The authors in investigated FFR scheme in higher order sectorization deployments and proposed a new spectrum efficiency-based users classification method. In, a dynamic FFR was proposed to increase the trunking gain, while satisfying minimum data rate requirement. The soft frequency reuse (SFR) scheme divides the whole bandwidth into three equal parts and the two parts are used for the cell-center users (CCUs) whereas another part for the CEUs in a way that no adjacent sectors can access to the same bandwidth for their CEUs. By transmitting higher power for CEUs than for CCUs, SFR can mitigate ICI to a tolerable level. Adaptive SFR algorithm (ASFR) dynamically allocates subcarriers and power to achieve the improvement of system capacity.

Multi-level soft frequency: Multi-level soft frequency reuse (ML-SFR) was presented to achieve a better interference pattern further and improve the cell throughput compared with twolevel SFR. The authors in proposed a utility-based energy-efficient resource

allocation algorithm for the downlink transmissions in heterogeneous networks who employed the FFR method to mitigate the intra- and inter-cell interference.

The main contributions of this letter are as follows. A quasi-perfect resource allocation scheme for optimizing the performance of CEUs in FFR-aided LTE-A multi cell networks (Q-PRAFFR) is presented which splits cell-edge region, cell edge bandwidth and CEUs into six parts and allocates resource to CEUs with the predefined resource allocation priority that leads to the more uniform distance distribution among the CEUs allocated the same bandwidth in different cells.

Consequently, it mitigates the ICI, decreases the outage probability of the CEUs and increases the overall data rate compared with the state-of-the-art FFR technology.

CEUs location: In this letter, we have proposed and proved the theorem of perfect resource allocation. Considering the randomness of the CEUs location in realistic networks, we follow the perfect resource allocation idea and formulate a new quasi-perfect resource allocation to improve the performance of CEUs by optimizing the CEUs resource allocation which results in mitigating the ICI. The new proposed scheme can play a vital role in ICI coordination when used in the realistic LTE-A system and the future 5G systems. Numerical results show that Q-PRAFFR not only improves the throughput of the cell but also decreases the outage probability of the CEUs.