dc.description.abstract |
All wireless networks, including 5G networks using multi user multiple-input multiple-output (Mu-MIMO) systems, are characterized by simple media access. However, this
characteristic makes them victim to eavesdropping attack. To reduce this problem a
security solution has been suggested at the lower (physical) layer of a communication
system by generating artificial noise (AN) in the null space of the legal receiver channel.
In addition, larger number of antennas error detecting and correcting approaches are also
suggested for security solution with the incorporation of AN.
In this thesis, a cascading of polar and convolutional coding techniques with AN for up-link Mu-MIMO system are used. Secrecy capacity and error performance of the system
is studied using simulation by Matlab software. The error performance of the uncoded
system, polar, convolutional and the cascading of the two code is evaluated. The ob-tained results show cascaded code requires a minimum signal to noise power ratio (SNR)
value to achieve the same bite error rate (BER) value as compared to the other. The
cascading system gives 4 dB coding gain relative to polar code to achieve 10
−5
BER value
and polar code outperforms convolutional code. The uncoded system requires the highest
SNR value. By considering the effect of eves, the error performance of the main channel,
legal receiver and the eavesdropper is also compared. Our result show that, with a 2 dB
performance gap between the legitimate receiver and the main channel, the eavesdropper
performance goes to worse above 25 dB. Increasing the allocating power to eaves, makes
more worse its BER performance, but a performance gap in the legitimate receiver is also
slightly increased. The capacity performance comparison of the eavesdropper and the le-gitimate receiver is also done, with different base station antennas, eavesdropper antennas
and coding rate. The results show that, increasing the eavesdropper antenna decreases
the secrecy of the system while decreasing the coding rate increases the reliability of the
system.
Key Words: AN, Convolutional code, eavesdropper, Mu-MIMO, Polar code,
Secrecy capacity |
en_US |