Joint channel impulse response and noise-variance estimation for OFDM/SDMA systems based on expectation maximization
Authors: Zhang, J., Mu, X. and Hanzo, L.
Journal: IEEE Vehicular Technology Conference
A joint channel impulse response (CIR) and noisevariance estimation scheme is proposed for multi-user Multiple-Input-Multiple-Output (MIMO) Orthogonal Frequency-Division Multiplexing / Space Division Multiple Access (OFDM/SDMA) systems, which is based on the Expectation Maximization (EM) algorithm. Multiple users communicating over time-invariant and/or time-variant channels are considered in this paper. Channel estimation becomes quite challenging in this scenario, since an increased number of independent transmitter-receiver links having different statistical characteristics have to be simultaneously estimated for each subcarrier. The proposed EM-based joint CIR and noise-variance estimator designed for multiuser MIMO OFDM/SDMA system is shown to simultaneously estimate the time-invariant and time-variant CIRs as well as noise-variance. ©2010 IEEE.