الفهرس 
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Abstract
Cellular systems demand higher throughput as an important requirement for future applications. Multi-hop Relay networks are adopted to fulfill the demanding coverage and capacity requirements for uplink as well as downlink in a cost efficient way. Adding relay Station to the network may increase the throughput of cell edge users by utilizing the radio channel usage. This directly improves the performance of cell center users, hence the total system performance.A number of research studies introduced new algorithms or schemes to improve the performance of multi-hop networks. One of the most important techniques is the resource scheduling that make efficient use of frequency resources. Using one of the scheduling schemes, the performance will be improved. Another promising technique called MIMO is used to improve the cellular networks performance by overcoming the limited channel capacity caused by SISO transmission. Multiple Input Multiple Output (MIMO) can enhance the received SNR, and data rates based on spatial diversity and multiplexing. Higher order MIMO may achieve better system performance improvement.Higher order modulation schemes can also be considered to enhance the received data rate, but they provide higher bit error rates. To overcome this problem higher SNR can be used with high order Modulation schemes. Hence coding rate may be chosen in proportional to Signal to Noise Ratio (SNR). The switching between modulation orders, and coding rates according to the received SNR is known as adaptive modulation and coding (AMC). Another link adaptation promising technique rather than AMC is, Adaptive MIMO switching (AMIMOS).Most cellular networks research studies focus on downlink traffic scenarios. However, in all 4G and future networks this situation is changed, since popular file transfer and social network applications require large uplink traffic to overcome the two link bottleneck problems. Therefore, the work reported in this thesis will focus on the LTE-A Uplink performance improvement.In the Thesis, the uplink LTE-A multi-hop network performance was studied, and alternative solutions proposed to improve the performance. The effect of different arrival rates from random positions of UEs in the cell were taken into consideration. File uploading will be according to a given scheduling scheme.Extensive study for the following points are considered in details: (1) Introduce performance model to calculate the RS service in which the UE can transmit to eNB using the RS faster than direct transmission, and estimate the number of RSs covering the cell. (2) Study the effect of the RS and its placement in the network on the LTE-A uplink performance when the UEs transfer files from random places in the cell using different arrival rates. This may be performed based on scheduling algorithms and adaptive modulation and coding schemes (3) Study the effect of path loss and UE transmitted power on RS position and network capacity (4) Evaluate the Network performance based on different antenna configuration modes are considered. (5) Study the link bottleneck effect using Radio-interface RS-eNB link. (6) Evaluate the network performance using Adaptive MIMO, Modulation and Coding switching with proposed switching scheme, and compare its performance with the standard MIMO schemes including high order 2×4MIMO. (7) Introduce a proposed transmission scheme to improve the received SNR, and the total throughput will be improved as a result. (8) Introduce a proposed scheduling scheme for Uplink LTE-A used for zero Multi-hop links overflow. (9) Formulate RS placement optimization problem and estimate the optimum position for one or more fixed relay stations (FRSs). Then, the results are compared with near optimum placement came from estimated closed form equation. (10) Develop a solution for moving hotspot improvement problem by introducing Nomadic Relay Stations with periodic optimized location update.The simulation results and analysis show significant improvement in uplink LTE-A network performance using RS at optimum placement based on proposed improvement algorithms and schemes. The maximum achieved throughput gain reached 180% of the throughput of SISO system without RS under the same parameters and assumptions. The results may also show significant moving Hotspot improvement using the proposed adaptive nomadic relay.