Análisis de la técnica NOMA-OFDM en un canal multitrayecto y usando estimación de canal

Abstract

NOMA (Non-Orthogonal Multiple Access) is a non-orthogonal access technique that can increase spectral efficiency and is considered a candidate technology for 5G. NOMA-OFDM combines the non-orthogonal access of NOMA with OFDM, which is widely used due to several advantages such as its high spectral efficiency. Channel estimation is an essential process in a NOMA-OFDM system, so in this paper a channel estimation scheme with preamble for the downlink is proposed considering a multipath channel and the LS (Least Square) technique. The analysis of the results is performed based on graphs of BER (Bit Error Rate) vs Eb/N0 (Energy per bit to noise power spectral density ratio) of the simulation implemented in Matlab and shows that channel estimation is possible with the LS method with the advantage that it is a simple technique although it produces a degradation of approximately 3 dB in the BER compared to the ideal case of perfect estimation. In addition, the results show that the selection of the injection factor is very important for the performance of the users to be adequate.