A. Yahya

Effect of relay location on two-way DF and AF relay for multi-user system in LTE-A cellular networks

In order to meet the increasing demand and stringent design requirements for coverage expansion, throughput and capacity enhancement relay Node (RNs) has been considered as a promising solution to LTE-A Point-to-Multi-Point (PMP) networks. In this paper two scenarios are proposed, at the first scenario this work introduced the performance analysis of two-way Multiuser system of half duplex to AF (Amplify and Forward) and DF (Decoded and Forward) Relay. At the second scenario the position of a relay problem for the maximum capacity enhancement of a two-way Relay Node (RN) to achieve an efficient and scalable Long Term Evolution-Advanced (L TE-A) wireless network design is investigated., the optimum relay location that provides the greatest achievable rate with two-way performance is derived. It has been observed from the results that the optimum location of AF relay is 0.72 of the cell coverage radius, whereas the DF relay achieved a maximum bit rate when the relay location is at 0.52 from the cell coverage radius. The proposed method will help LTE-A designer to solve relay placement problem.

Enhancing link quality in a multi-hop relay in LTE-A employing directional antenna

This paper proposes a new approach for enhancing link quality between relay node (RN) and base station (BS). Two types of antennas were proposed at the relay, the first type is the directional antenna, which is directed toward the base station to improve the relay link quality, thereby reducing outage probability by increasing relay link capacity. The second type is the omni-directional antenna, which is used for the exchange of information between the RN and attached users. An improvement of 32% in capacity and 25% in received signal strength at the relay link has been observed. An ATDI simulator, which handles the digital cartography for the first tier of interference in urban areas, verified the numerical results.

REDUCING TRANSMITTED POWER OF MOVING RELAY NODE IN LONG-TERM EVOLUTION-ADVANCED CELLULAR NETWORKS

Wireless multi-hop relay networks have become very significant technologies in mobile communications. These networks ensure data rate transfer and covera ge extension with a low cost. In this study two typ es of relay are studied; Fixed Relay Node (FRN) and Moving Relay Node (MRN). Where system analyses for uplink and downlink transmission are derived in thi s study. Moreover the optimal relay location of FRN was proposed to provide a maximum achievable rate at user in cell edge region. Finally, a new algorith m was suggested to balance and control on the transmi tted power of MRN over cell size to provide the required SNR and throughput at the users inside veh icle with reducing the consumption transmitted rela y power. Numerical results indicate an enhancement in received signal strength for users at the cell edg e from (-90 to -65) dBm and 40% increment from all cell size after de ploying FRN at proposed locations. As well as, the results revealed that there is saving nearl y 75% from transmitted power in MRN after using proposed algorithm. ATDI simulator was used to verify the nu merical results, which deals with real digital cartographic and standard formats for terrain.

Low complexity burst allocation algorithm with high frame utilization for Mobile WiMAX (802.16e)

Burst allocation is one of the important parameter that affects the performance of the Mobile WiMAX systems. The burst allocation algorithm is responsible about calculating the appropriate dimensions and location of each users data to construct the bursts within the downlink subframe in term of the number of slots per user. Resource wastage in the form of unused and unallocated slots is a common problem accompanies burst allocation. In this paper, a Sequential Burst Allocation (SBA) algorithm is proposed to overcome frame wastage. The SBA algorithm is based on the sequential allocation of user slots. SBA restricts the unused slots, and eliminates unallocated slots between data bursts through burst fragmentation when necessary is forced to be used. Continuous allocation from one frame to the next has a significant impact on reducing resource wastage. It has been observed from the results that the percentage difference of the frame utilization between SBA and Standard algorithms (ST) is 32.84 %, which achieved significant reduction of resource wastage per frame, leading to more exploit of the WiMAX frame.

Increasing the coverage area through relay node deployment in long term evolution advanced cellular networks

Wireless multi-hop relay networks have become very important technologies in mobile communications. These networks ensure high throughput and coverage extension with a low cost. The poor capacity at cell edges is not enough to meet with growing demand of high capacity and throughput irrespective of user’s placement in the cellular network. In this paper we propose optimal placement of relay node that provides maximum achievable rate at users and enhances the throughput and coverage at cell edge region. The proposed scheme is based on the outage probability at users and taken on account the interference between nodes. Numerical analyses along with simulation results indicated there are an improvement in capacity for users at the cell edge is 40% increment from all cell capacity.

Mobile WiMAX Resource Allocation Design Goals: Key Features/Factors/Issues

The technical design challenge of Mobile WiMAX is to exploit the limited available spectrum of the downlink subframe efficiently while achieving the desired goals behind the resource management algorithms. Various goals can be achieved when the resource management algorithms exploited in the right direction. This paper presents the coordination between MAC layer scheduler objectives and PHY layer burst allocation algorithm design parameters. Utilizing PHY layer operation mode with MAC layer coordination leads to increase the proportion of the desired objectives achievement. The presented methodologies of the burst allocation algorithm design can achieve higher satisfaction of MAC requirements and avoid the limitations. The study has demonstrated that resource allocation algorithm requires many factors and parameters to be employed in the correct direction to enable efficient use of the downlink resources to satisfy MAC layer requirements.

Mobile WiMAX resource allocation algorithms guidelines and performance assessment

Resource allocation management is one of the effective factors of WiMAX base station performance. Various goals could be achieved when the resource allocation scheme exploits in the right direction. However, the assessment of the resource allocation algorithms lacks to a uniform performance metrics. Where, most of the researches are trying to show authors perspectives in the finding results to show the design pros, whilst the overall performance in resource allocation perspective mostly not exist. This paper proposes a new style of primary assessment for the resource allocation algorithms to ease conducting a fair comparison between the relevant algorithms. The assessment methodology based on a set of evaluation questions. The obtained results show that the new assessment method distinguishes the overall performance to provide fair comparison.