Joint Channel Impulse Response and Noise-Variance Estimation for OFDM/SDMA Systems Based on Expectation Maximization

Abstract—A joint channel impulse response (CIR) and noisevariance estimation scheme is proposed for multi-user MultipleInput-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 EMbased 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.

• Type: Journal
• Year: 2010
• Where: VTC
• Authors: Jiankang Zhang, Xiaomin Mu, Lajos Hanzo
• Keywords: Channel Impulse Response, Communications, Noisevariance Estimation Scheme, Space Division Multiple Access, VTC 2010