5 research outputs found
CFO Estimation for OFDM-based Massive MIMO Systems in Asymptotic Regime
Massive multiple input multiple output (MIMO)
plays a pivotal role in the fifth generation (5G) wireless networks.
However, the carrier frequency offset (CFO) estimation is a challenging issue in the uplink of multi-user massive MIMO systems.
In fact, frequency synchronization can impose a considerable
amount of computational complexity to the base station (BS)
due to a large number of BS antennas. In this paper, thanks
to the properties of massive MIMO in the asymptotic regime,
we develop a simple synchronization technique and derive a
closed form equation for CFO estimation. We show that the phase
information of the covariance matrix of the received signals is
solely dependent on the users’ CFOs. Hence, if a real-valued pilot
is chosen, the CFO values can be straightforwardly calculated
from this matrix. Hence, there is no need to deal with a complex
optimization problem like the other existing CFO estimation
techniques in the literature. Our simulation results testify the
efficacy of our proposed CFO estimation technique. As we have
shown, the performance of our method does not deteriorate as
the number of users increases