Kamarul Ariffin Noordin

A novel scheduling algorithm based on game theory and multicriteria decision making in LTE network

Fourth generation wireless networks provide mobile users with high data rate and quality of services, such as Long Term Evolution (LTE), which has been developed by the 3rd Generation Partnership Project (3GPP). However, 3GPP is not a standardized scheduling algorithm to utilize LTE properties in smart grid applications. This paper proposes a two-level scheduling scheme composed of cooperative game theory (bankruptcy and shapely) and Technique for Order Performance by Similarity to Ideal Solution (TOPSIS). The proposed algorithm improves resource allocation for three smart grid applications, namely, voice, video surveillance, and metering data. On the first level, bankruptcy and shapely value algorithm fairly distribute the resources among smart grid applications. On the second level, TOPSIS algorithm allocates the resources among applications users based on their criteria and the applications preferences. Moreover, the systems performance has been evaluated in terms of throughput, delay, and fairness index. The proposed algorithm is compared with existing algorithms, such as proportional fairness, modified largest weighted delay first, and exponential rule schemes. The results show a significant improvement compared to other algorithms. This paper presents a novel technique consisting of both TOPSIS and game theory algorithms to study three smart grid applications. The novel algorithm has proven to be an effective scheduling technique for smart grid applications.

Cross-Layer Optimization Architecture for WiMAX Systems

The traditional layered-protocol architecture seems to be inefficient in wireless network environment as the wireless channel is time-varying in nature. The IEEE 802.16 standard which the WiMAX system is based upon is also designed according to such layered-protocol stacks. To obtain overall performance gain however, cross-layer optimization is essential. In this paper, we propose a cross-layer optimization architecture for WiMAX system. It consists of a cross-layer optimizer which acts as an interface between MAC and PHY layers. It gathers and optimized the parameters from both layers to achieve optimum performance gain. Preliminary simulations were conducted to justify the need for cross-layer optimization.

A Novel LTE Scheduling Algorithm for Green Technology in Smart Grid

Smart grid (SG) application is being used nowadays to meet the demand of increasing power consumption. SG application is considered as a perfect solution for combining renewable energy resources and electrical grid by means of creating a bidirectional communication channel between the two systems. In this paper, three SG applications applicable to renewable energy system, namely, distribution automation (DA), distributed energy system-storage (DER) and electrical vehicle (EV), are investigated in order to study their suitability in Long Term Evolution (LTE) network. To compensate the weakness in the existing scheduling algorithms, a novel bandwidth estimation and allocation technique and a new scheduling algorithm are proposed. The technique allocates available network resources based on application’s priority, whereas the algorithm makes scheduling decision based on dynamic weighting factors of multi-criteria to satisfy the demands (delay, past average throughput and instantaneous transmission rate) of quality of service. Finally, the simulation results demonstrate that the proposed mechanism achieves higher throughput, lower delay and lower packet loss rate for DA and DER as well as provide a degree of service for EV. In terms of fairness, the proposed algorithm shows 3%, 7 % and 9% better performance compared to exponential rule (EXP-Rule), modified-largest weighted delay first (M-LWDF) and exponential/PF (EXP/PF), respectively.

A comprehensive review on coordinated multi-point operation for LTE-A

Abstract With the enormous increase in application demands and users data rate, high Quality of Service (QoS) has attracted significant attention from the mobile operators and academia in the past few years. Coordinated Multi-Point (CoMP) operation system provides a valid solution to enhanced throughput and coverage performance by reducing the interference, especially for cell-edge users. In CoMP operation, multiple Base Stations (BS) coordinate with each other in such a way that the users information signal from neighboring evolved Node B (eNB) reduces interference or even can be combined to improve received signal quality. CoMP transmission is depending on the sharing coordination information via backhaul links, usually, consist of users feedback that explains channel condition. This paper provides a brief vision into the CoMP technology including its architecture, sets, and promising approaches that can be employed in the future network. It discussion extends to the deployment scenarios in which CoMP schemes will likely be most beneficial in the modern backhaul designs available today. The study also covers the most well-known CoMP types such as coordinated scheduling and beamforming, joint transmission and dynamic point selection in detail along with its issues and current possible solutions. Most of the ideas presented are presently being studied and may diverge throughout the standardization work. In addition, a range of practical issues is identified and addressed in the deployment of CoMP in Heterogeneous Network (HetNet) and Multiple Input Multiple Output (MIMO) system, such as backhaul traffic, synchronization, and feedback design. This article provides an insight into the current research problem and also suggested the most challenging research gaps that may be useful for future research. It is shown that CoMP leads to both network throughput and capacity expansion in Long Term Evolution Advanced (LTE-A) network and can significantly provide more enhancements in spectrum efficiency and network performance gain with better cooperative coordination strategies.

Performance analysis of an all-optical OFDM system in presence of non-linear phase noise

The potential for higher spectral efficiency has increased the interest in all-optical orthogonal frequency division multiplexing (OFDM) systems. However, the sensitivity of all-optical OFDM to fiber non-linearity, which causes nonlinear phase noise, is still a major concern. In this paper, an analytical model for estimating the phase noise due to self-phase modulation (SPM), cross-phase modulation (XPM), and four-wave mixing (FWM) in an all-optical OFDM system is presented. The phase noise versus power, distance, and number of subcarriers is evaluated by implementing the mathematical model using Matlab. In order to verify the results, an all-optical OFDM system, that uses coupler-based inverse fast Fourier transform/fast Fourier transform without any nonlinear compensation, is demonstrated by numerical simulation. The system employs 29 subcarriers; each subcarrier is modulated by a 4-QAM or 16-QAM format with a symbol rate of 25 Gsymbol/s. The results indicate that the phase variance due to FWM is dominant over those induced by either SPM or XPM. It is also shown that the minimum phase noise occurs at -3 dBm and -1 dBm for 4-QAM and 16-QAM, respectively. Finally, the error vector magnitude (EVM) versus subcarrier power and symbol rate is quantified using both simulation and the analytical model. It turns out that both EVM results are in good agreement with each other.

Wireless Location Positioning Based on WiMAX Features - A Preliminary Study

In this paper, we exploit the potential of positioning technologies in wireless broadband communications, which are based on worldwide interoperability for microwave access (WiMAX), in particular the IEEE802.16* standards. By utilizing the additional features in WiMAX including multiple input multiple output (MIMO), adaptive modulation and coding (AMC), beamforming, relay station and power control, we believe that the features can be used for enhancing the location estimation accuracy in location services.

Hybrid network combining PLC and IEEE802.16 for hospital environment

This paper presents a novel hospital network which delivers broadband with Quality of Service (QoS) guaranteed by IEEE 802.16/WiMAX and Power Line Communication (PLC) systems. Through the utilization of the QoS features of IEEE 802.16 and PLC systems jointly, the proposed system enables simultaneous transmission of various types of medical data traffic while remaining the advantages of operation flexibility and low deployment cost. Performance is evaluated to demonstrate that the proposed network not only provides throughput guarantee, but also considers QoS requirement of the medical applications.

Genetic algorithm approach for dynamic configuration of Multicast Broadcast Single Frequency Network deployment in LTE

Multimedia Broadcast Multicast service (MBMS) is used for the delivery of multimedia contents such as video and live mobile TV in a point-to-multipoint (PtM) mode of transmission. In Long Term Evolution (LTE), another technique is offered to increase the capacity and speed of transmission via Multimedia Broadcast / Multicast service over a Single Frequency Network (MBSFN). MBSFN is a large network consisting of multiple cells where the signal transmission are tightly time synchronized among them in a given duration. The configuration of which cells comprise a MBSFN area is necessary to adapt changes of MBMS users location. In this paper, a genetic algorithm (GA) approach is proposed for dynamic configuration of MBSFN area. The proposed algorithm searches the optimal solution for MBSFN area deployment based on location where the densities of MBMS user equipments (UEs) are higher. The UEs that are expensive to cover would be sacrificed from being in MBSFN mode of transmission.

A new power control game in two-tier femtocell networks

In this paper, the problem of distributed power control is investigated and analyzed for two-tiered femtocell networks that share the same frequency band with the central macrocell. Femtocell users are associated with a proper utility function via pricing, which represents the ratio of users signal-to-interference-noise ratio (SINR) and the exponential price of power consumed. Assuming a femtocell user seeks selfishly to maximize its utility function under the imposed constraints, a femtocell non-cooperative power control game (FNPC) is formulated. We prove the existence and uniqueness of the Nash Equilibrium output for the game model of power control algorithm. Numerical results show the effectiveness of pricing parameters in the penalty function to the speed of convergence and power consumed.

A New SIR-Based Sigmoid Power Control Game in Cognitive Radio Networks

Interference resulting from Cognitive Radios (CRs) is the most important aspect of cognitive radio networks that leads to degradation in Quality of Service (QoS) in both primary and CR systems. Power control is one of the efficient techniques that can be used to reduce interference and satisfy the Signal-to-Interference Ratio (SIR) constraint among CRs. This paper proposes a new distributed power control algorithm based on game theory approach in cognitive radio networks. The proposal focuses on the channel status of cognitive radio users to improve system performance. A new cost function for SIR-based power control via a sigmoid weighting factor is introduced. The existence of Nash Equilibrium and convergence of the algorithm are also proved. The advantage of the proposed algorithm is the possibility to utilize and implement it in a distributed manner. Simulation results show considerable savings on Nash Equilibrium power compared to relevant algorithms while reduction in achieved SIR is insignificant.