Abstract:
The increasing demands for high throughput in the fifth generation (5G) are posing
different challenges for the design of access schemes. To meet these challenges, new multiple
access (MA) schemes are being developed. Non-orthogonal multiple access (NOMA) is
considered as one of the outperformance multiple access technique to deal with the heterogeneous
wireless networks. This feature makes NOMA capable of increasing spectral efficiency gain over
the conventional multiple access schemes. Non-Orthogonal Multiple Access (NOMA), which will
resolve power distribution issues, high data rate requirements, design challenges and limitations
of all generations. NOMA uses the power domain to separate signals from each other. It is an
additional form for providing a multi-user access scheme. It gives a new dimension in which
signals can be separated and given access to a base station. NOMA uses the power domain to
separate signals. Code domain multiple access (CDMA) has been adopted as the multiple access
scheme for the third generation cellular mobile systems because of it’s flexibility in cell planning,
support for different rate traffics, user capacity and robustness to multipath fading channel
conditions. One of the advantage of CDMA is to increase the number of simultaneous users (user
capacity) with acceptable error performance. In this thesis power allocation issue will be discussed.
For previous work in NOMA power allocation to multiple users is a big challenge. For multiple
users the power allocation strategy is under investigation. In our research we will reduce this issue
by assigning different codes to all users in the cell. We are going to combine CDMA with NOMA
for multiuser capacity enhancement and better utilizing of power allocation scheme, for designing
hybrid technique BER performance of CDMA under different channels is analyzed, BER
performance of SISO-NOMA is analyzed in different channels as AWGN, Rician, Rayleigh and
NYUSIM channel models. We designed a hybrid CDMA-NOMA scheme and BER is analyzed
under different fading channels specially in NYUSIM channel model, the 5G channel model.
