Val Costa | University of Surrey (original) (raw)

Papers by Val Costa

ABSTRACT In this paper, we propose an improved Inter-Cell Interference Coordination (ICIC) for em... more ABSTRACT In this paper, we propose an improved Inter-Cell Interference Coordination (ICIC) for emerging multi-cell wireless systems. The ICIC provided in this paper gives a proper inter-cell resource allocation by employing the concept of interference avoidance and describes the inter-relationship of all base stations in a holistic way. We use a semi-centralized ICIC scheme which divides the global optimum problem into a multicell and multi-user problem. Our performance metrics are the aggregate sector throughput and the critical throughput of a multi-cell system. The critical throughput is defined as the 5th percentile of the aggregate user throughput. Simulation results confirm the increased effectiveness of the proposed ICIC in both metrics over a number of state-of-the-art interference avoidance schemes. Keywords - component; Inter-cell RRM; Semi-centralized RRM; Linear/Binary Optimization; Inter-Cell Interference Coordination.

IEEE Communications Surveys & Tutorials, 2013

The widely accepted OFDMA air interface technology has recently been adopted in most mobile stand... more The widely accepted OFDMA air interface technology has recently been adopted in most mobile standards by the wireless industry. However, similar to other frequencytime multiplexed systems, their performance is limited by intercell interference. To address this performance degradation, interference mitigation can be employed to maximize the potential capacity of such interference-limited systems. This paper surveys key issues in mitigating interference and gives an overview of the recent developments of a promising mitigation technique, namely, interference avoidance through inter-cell interference coordination (ICIC). By using optimization theory, an ICIC problem is formulated in a multi-cell OFDMA-based system and some research directions in simplifying the problem and associated challenges are given. Furthermore, we present the main trends of interference avoidance techniques that can be incorporated in the main ICIC formulation. Although this paper focuses on 3GPP LTE/LTE-A mobile networks in the downlink, a similar framework can be applied for any typical multi-cellular environment based on OFDMA technology. Some promising future directions are identified and, finally, the state-of-the-art interference avoidance techniques are compared under LTEsystem parameters.

IEEE Communications Letters, 2013

In this paper we present a novel distributed Inter-Cell Interference Coordination (ICIC) scheme f... more In this paper we present a novel distributed Inter-Cell Interference Coordination (ICIC) scheme for interferencelimited heterogeneous cellular networks (HetNet). We reformulate our problem in such a way that it can be decomposed into a number of small sub-problems, which can be solved independently through an iterative subgradient method. The proposed dual decomposition method can also address problems with binary-valued variables. The proposed algorithm is compared with some reference schemes in terms of cell-edge and total cell throughput.

The widely accepted OFDMA air interface technology has recently been adopted in most mobile stand... more The widely accepted OFDMA air interface technology has recently been adopted in most mobile standards by the wireless industry. However, similar to other frequency-time multiplexed systems, their performance is limited by inter-cell interference. To address this performance degradation, interference mitigation can be employed to maximize the potential capacity of such interference-limited systems. This paper surveys key issues in mitigating interference and gives an overview of the recent developments of a promising mitigation technique, namely, interference avoidance through inter-cell interference coordination (ICIC). By using optimization theory, an ICIC problem is formulated in a multi-cell OFDMA-based system and some research directions in simplifying the problem and associated challenges are given. Furthermore, we present the main trends of interference avoidance techniques that can be incorporated in the main ICIC formulation. Although this paper focuses on 3GPP LTE/LTE-A mobile networks in the downlink, a similar framework can be applied for any typical multi-cellular environment based on OFDMA technology. Some promising future directions are identified and, finally, the state-of-the-art interference avoidance techniques are compared under LTE-system parameters

In this paper we present a novel distributed Inter-Cell Interference Coordination (ICIC) scheme f... more In this paper we present a novel distributed Inter-Cell Interference Coordination (ICIC) scheme for interference-limited heterogeneous cellular networks (HetNet). We reformulate our problem in such a way that it can be decomposed into a number of small sub-problems, which can be solved independently through an iterative subgradient method. The proposed dual decomposition method can also address problems with binary-valued variables. The proposed algorithm is compared with some reference schemes in terms of cell-edge and total cell throughput.

In this paper, we propose an improved Inter-Cell Interference Coordination (ICIC) for emerging mu... more In this paper, we propose an improved Inter-Cell Interference Coordination (ICIC) for emerging multi-cell wireless systems. The ICIC provided in this paper gives a proper inter-cell resource allocation by employing the concept of interference avoidance and describes the inter-relationship of all base stations in a holistic way. We use a semi-centralized ICIC scheme which divides the global optimum problem into a multi-cell and multi-user problem. Our performance metrics are the aggregate sector throughput and the critical throughput of a multi-cell system. The critical throughput is defined as the 5th percentile of the aggregate user throughput. Simulation results confirm the increased effectiveness of the proposed ICIC in both metrics over a number of state-of-the-art interference avoidance schemes.

IEEE Communications Surveys & Tutorials, 2013

IEEE Communications Letters, 2013

The widely accepted OFDMA air interface technology has recently been adopted in most mobile stand... more The widely accepted OFDMA air interface technology has recently been adopted in most mobile standards by the wireless industry. However, similar to other frequency-time multiplexed systems, their performance is limited by inter-cell interference. To address this performance degradation, interference mitigation can be employed to maximize the potential capacity of such interference-limited systems. This paper surveys key issues in mitigating interference and gives an overview of the recent developments of a promising mitigation technique, namely, interference avoidance through inter-cell interference coordination (ICIC). By using optimization theory, an ICIC problem is formulated in a multi-cell OFDMA-based system and some research directions in simplifying the problem and associated challenges are given. Furthermore, we present the main trends of interference avoidance techniques that can be incorporated in the main ICIC formulation. Although this paper focuses on 3GPP LTE/LTE-A mobile networks in the downlink, a similar framework can be applied for any typical multi-cellular environment based on OFDMA technology. Some promising future directions are identified and, finally, the state-of-the-art interference avoidance techniques are compared under LTE-system parameters

In this paper we present a novel distributed Inter-Cell Interference Coordination (ICIC) scheme f... more In this paper we present a novel distributed Inter-Cell Interference Coordination (ICIC) scheme for interference-limited heterogeneous cellular networks (HetNet). We reformulate our problem in such a way that it can be decomposed into a number of small sub-problems, which can be solved independently through an iterative subgradient method. The proposed dual decomposition method can also address problems with binary-valued variables. The proposed algorithm is compared with some reference schemes in terms of cell-edge and total cell throughput.