On the equivalence between the MMSE receiver and Tikhonov regularization

In the Multi Input Multi Output (MIMO) antenna system, it is known that the MMSE receiver is equivalent to Tikhonov regularization. Given that, we develop a generalized receiver based on regularization with different penalty functions that penalize the received symbols outside the convex hull of the modulating constellation, namely, dead-zone and infinity norm penalty functions. Simulation results show that the proposed receiver outperform the MMSE receiver by as high as 5-dB at low SNR and 1-dB at high SNR.