515 research outputs found
Vector Approximate Message Passing based Channel Estimation for MIMO-OFDM Underwater Acoustic Communications
Accurate channel estimation is critical to the performance of orthogonal
frequency-division multiplexing (OFDM) underwater acoustic (UWA)
communications, especially under multiple-input multiple-output (MIMO)
scenarios. In this paper, we explore Vector Approximate Message Passing (VAMP)
coupled with Expected Maximum (EM) to obtain channel estimation (CE) for MIMO
OFDM UWA communications. The EM-VAMP-CE scheme is developed by employing a
Bernoulli-Gaussian (BG) prior distribution for the channel impulse response,
and hyperparameters of the BG prior distribution are learned via the EM
algorithm. Performance of the EM-VAMP-CE is evaluated through both synthesized
data and real data collected in two at-sea UWA communication experiments. It is
shown the EM-VAMP-CE achieves better performance-complexity tradeoff compared
with existing channel estimation methods.Comment: Journal:IEEE Journal of Oceanic Engineering(Date of
Submission:2022-06-25
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