en 5-Signal Processing Signal Processing Research Paper Research Paper <div style="text-align: justify;"><span style="color:#000000;"><span style="font-size:14px;"><span style="font-family:Times New Roman;">Through beamforming, the desired signal is estimated by calculating the weighted sum of the input signals of an array of antenna elements. In the classical beamforming methods, computing the optimal weight vector requires prior knowledge on the direction of arrival (DoA) of the desired signal sources. However, in practice, the DoA of the signal of interest is unknown. In this paper, we introduce two different deep-neural-network-based beamformers which can estimate the signal of interest while suppressing noise and interferences in two/three stages when the DoAs are unknown. Employing deep neural networks (DNNs) such as convolutional neural networks (CNNs) and bidirectional long short-term memory (bi-LSTM) networks enables the proposed method to have better performance than existing methods. In most cases, the output signal to interference and noise ratio (SINR) of the proposed beamformer is more than 10dB higher than the output SINR of the classical beamformers.</span></span></span></div> Adaptive Digital Beamforming, Bidirectional Long Short-Term Memory, Convolutional Neural Network. 92 104 http://ijeee.iust.ac.ir/browse.php?a_code=A-10-78-28&slc_lang=en&sid=1 P. Ramezanpour parham.ramezanpour@yahoo.com 1800319475328460013413 1800319475328460013413 No Department of Electrical Engineering, Iran University of Science and Technology (IUST), Tehran, Iran. M. Aghababaie majid_aghababaie@alumni.iust.ac.ir 1800319475328460013414 1800319475328460013414 No Department of Electrical Engineering, Imam Khomeini Marine Science University, Mazandaran, Iran. M. R. Mosavi m_mosavi@iust.ac.ir 1800319475328460013415 1800319475328460013415 Yes Department of Electrical Engineering, Iran University of Science and Technology (IUST), Tehran, Iran. D. M. de Andrés diego.martin.de.andres@upm.es 1800319475328460013416 1800319475328460013416 No ETSI de Telecomunicación, Universidad Politécnica de Madrid, Madrid, Spain.