Performance Analysis of Enhanced Downlink Transmission in MIMO-NOMA Networks under Rician Fading Channels

Abstract This paper investigates downlink transmission in multiple-input multiple-output (MIMO) non-orthogonal multiple access (NOMA) networks under Rician fading channels. An analytical framework for user signal-to-interference-plus-noise ratio (SINR) and bit error rate (BER) is developed. Numerical results are given to show that the outage probability is significantly decreased with higher transmit power, especially for cell-edge users, since NOMA is a good power allocation scheme. Furthermore, at higher SINR, the Bit-Error-Rate (BER) is reduced for all users, though such a user located far from the transmitter sees improved performance. This shows that MIMO NOMA presents an inter-user interference mitigation technique, and the closer users will benefit most. Overall, in comparison with SIMO NOMA, the MIMO NOMA will have better performance in either outage or BER reduction because of multi-antenna.