Behrooz Razeghi

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In this paper, we propose a new relay selection scheme for multi-user cooperation communications using a novel multiple criteria decision making optimization method. We consider jointly three criteria in our proposed relay selection method, two of which have been studied and employed for the process of relay selection in the literature, jointly and(More)
—We study and analyze coverage region in MIMO communication systems for a multiple-relay network with decode-and-forward (DF) strategy at the relays. Assuming that there is a line-of-sight (LOS) propagation environment for source-relay channels and channel state information is available at receivers (CSIR), we consider the objective of maximizing coverage(More)
—In this paper we study and analyze coverage region for half-duplex multiple-input multiple-output (MIMO) relay channel with amplify-and-forward (AF) strategy at the relay station. By assuming mixed Rayleigh and Rician fading channels with two different relay station situations, we consider the objective of maximizing coverage region for a given(More)
Some unique attributes of P2P networks such as cost efficiency and scalability, contributed for the widespread adaptation of these networks. Since P2P applications are mostly used in file-sharing, preserving anonymity of users has become a very important subject for researchers. As a result, a lot of methods are suggested for P2P networks to preserve(More)
A new three stage low-noise, high-gain operational amplifier (Op-Amp) is proposed in this paper. Design strategies are discussed for minimizing noise and increasing gain. Multipath nested Miller compensation used for three stage operational amplifier. The circuit is designed in the 0.18μm CMOS technology. The HSPICE software was used for simulation.(More)
The energy of all sensor nodes in wireless sensor networks is limited. For this reason, providing a method of communication between nodes and network administrator to manage energy consumption is crucial. In this paper, a centralized evolutionary clustering protocol for wireless sensor networks is proposed. The proposed protocol selects the appropriate(More)
It is known that, as opposed to point-to-point channel, separate source and channel coding is not optimal in general for sending correlated sources over multiuser channels. In some works joint source-channel coding has been investigated for some certain multiuser channels, e.g., multiple access channel (MAC) and broadcast channel (BC). In this paper, we(More)
In sending data from one point to another, such as transferring data between various components of a computer system, due to the existence of electromagnetic waves and other issues such as noise and attenuation, information may be changed in the middle of the track. Therefore, it is critical for receiver to ensure the accuracy of the information. For this(More)