الفهرس 
2: LAND MOBILE SATELLITEOnly 14 pages are availabe for public view
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Abstract
MO/lamed Ghaleb Mayhoub. Performance analysis of code division
multiple access system transmitted through nonlinear mobile satellite
channel. Doctor of Philosophy Degree, Ain Shams University. Faculty of
Engineering. Electronics and Communication Eng. Dept.
Tins work introduces two important subjects. The first one studies,
the performance analysis for one user of the direct sequence spread
spectrum (OS-SS) signal transmission through nonlinear mobile satellite
channel, while the second one introduces the performance analysis for
multi-user of the direct sequence code division multiple access (DSCDMA)
signal transmission through nonlinear mobile satellite channel.
The performance of DS-CDMA system, is performed using an
analytical model with both Gaussian process (GA) and improved Gaussian
approximation (IGA). Because of the inaccuracy of the Gaussian
approximation for the multiple access interference (MAl), an improved
Gaussian process with good accuracy has been used.
The impairments taken into consideration in the system are :
nonlinear effect of travelling wave tube (TWTA) on-board satellite (AMto-AM
and AM-to-PM conversions), additive white Gaussian noise
(AWGN), multiple access interference, and mobile propagation channels
which includes Shadowing, Rician, and Rayleigh effects, to describe
propagation in suburban, open, and urban areas respectively. System
performance in terms of the error probability is explored.
Also, a computer modelling and simulation is done for direct
sequence spread spectrum for one user, and for direct sequence code division multiple access for multi-user, with the impairment as mentioned
above.
Two techniques for the performance evaluation in computer
simulation have been used, Monte Carlo simulator and an importance
sampling techniques.
After the verification of simulation results with the obtained results of
analytical model, the simulation model is extended with considering the
up-link noise, in addition to the impairment taken in the analytical analysis.
The obtained results are done for different up-link thermal noise «(~Nfu).