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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.

Problem statement: In this study, the behavior of small scale fading channel due to a moving sink node of a Wireless Sensor Network (WSN) or moving of surrounding objects is presented. Approach: Specifically, this research introduces the effects of multipath and scattering on the transmitted signal due to mobile sink node with in forest or closed field filled of reflectors and scatters. Signal propagation above the cross canopy suffer attenuation and variance in the strength of the received signal. Results: The density of leaves in the crop changes over tim e thus results in more signal obstacles and attenuation at receiver node. The sink node is considered to be in stationary sta tus or it moves with speed not more than 1 m sec -1 , while the sensor nodes of the WSN is preplanned i n a fixed position. Conclusion/Recommendations: The modeling of pass band transmitted signal fused in Rayleigh fading channel of stationary and moving st atus of a receiver are derived. The fluctuation of RF signal, average received signal level, outage probability and the Doppler shift effects are simulated and a detailed analysis is present. The a ppropriate spatial distribution of the network nodes and the exist of a LOS component will highly necessary between sensor nodes and the sink node in agricultural applications. Indeed power con sumption must well maintain so packet loss due to less power level can be overcome. Best posit ion found is center of the application field of the greenhouse for the sink node in stationary situ ation, while for movement situation the best height of the sink node is to be little above line level of the sensor nodes.

Frequency hopping spread spectrum with noncoherent M-ary frequency shift keying system is considered. In this study Reed Solomon codes RS (255, 223) are employed in a standard error correction role to provide some Anti-Jamming (AJ) capability with 8-bit symbols. Noise has been added to RS encoded data, which is demodulated at RS decoder perfectly. Matlab simulations have been implemented for numerical results. Graphical results have been plotted between the probability of an erasure versus ρ using RS (255, 223) code for 1 and 2 kHz frequencies. The simulation results have proved that system having RS (255, 223) code with M = 32 require substantially less signal to jammer power ratio to achieve the same bit error probability.