Optimal Resource Allocation for Multicarrier NOMA in Short Packet Communications

Abstract

Wireless communication system needs a spectrum efficient, a power efficient and a cost efficient communication with high throughput to provide communication for ubiquities applications such as voice, data, picture, video, movies, multimedia services, Global Positional System (GPS), navigational system, telemedicine and other value added communication. Non-Orthogonal Frequency Division Multiplexing (NOMA) has become a popular technique for transmission of signals over wireless channels. In the first phase, MIMO system which uses NOMA is used. User signals are divided into parallel streams, using NOMA and are transmitted by the antenna array which propagates through the fading channel. signals are weighted using the Minimum Variance Distortionless Response (MVDR) where the weights are such that the output signal has minimum variance and the desired signal is not distorted. The parallel weighting scheme for interference cancellation leads to a faster, reliable and higher capacity system and results in parallel interference cancellation. Iterative process is also presented in this work, where the approximate weights are found out based on the minimum error value. Both the MVDR weighting and the approximate weighting are evaluated with the help of Bit Error Rate (BER) curves. The curves are plotted for both the Rayleigh and Rician channels. Various plots are obtained by varying the number of antennas in the array and also by varying the length of the user signal. All the BER curves achieved good results and from the analysis it is found that system performs better when Rayleigh channel was considered.