Channel Estimation of MIMO-NOMA System Based on a Variable Forgetting Factor Recursive Least Square Algorithm

The non-orthogonal multiple access (NOMA) technique for multi-input multi-output (MIMO) system is an emerging requirement for achieving high-speed spectral efficiency with low latency and massive connectivity of the devices. Instead of this in the MIMO-NOMA system to compensate the channel impairments increases the demand of channel estimation. In this paper, recursive least square (RLS) and variable forgetting factor recursive least square (VFFRLS) algorithms have been discussed for the channel estimation (CE) of NOMA systems. VFFRLS algorithm has been proposed to show the fast convergence rate and improved performance of the multi-user telecommunication systems than the RLS algorithm. The performance has been analyzed using mean square error (MSE) and bit error rate (BER). Therefore, to combat the channel dynamics, the VFFRLS CE algorithm is better to use for NOMA systems.