Channel Estimation for Massive MIMO in the Presence of Cauchy Noise

In this paper, we work on channel estimation techniques for massive multiple-input multiple-output (MIMO) with Cauchy noise. In the standard massive MIMO setup, the users transmit orthonormal pilots during the training phase and the received signal in the base station is projected onto each orthonormal pilot signal. This process is optimum when the noise is Gaussian. In other words, the obtained signal after this process is the sufficient statistic and we do not lose any information. We show that this process is not optimum when the noise is Cauchy. Hence, we propose a channel estimation technique for the unprocessed received signal. The proposed channel estimation technique is compared with the channel estimates that are obtained from the projected signal.