12041

11036

كارشناسي ارشد

الكترونيك

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1395

ده، [97]ص.: مصور، جدول، نمودار

ص. ع. به فارسي و انگليسي

رسول دهقاني

مهدي مهدوي

1395/11/05

كتابنامه

برق و كامپيوتر

مهندسي برق و كامپيوتر

ID11036

Reduction of Power Consumption in the 2 4 GHz ZigBee Transceiver by Implementation of an Improved CSMA CA Algorithm on FPGA Saeed Aghakhani s aghakhani@ec iut ac ir December 11 2016 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Dr Rasoul Dehghani Dehghani@cc iut ac ir Abstract Nowadays life without wireless communications is inconceivable Advances in CMOS technologyand the creation of smaller and smaller circuits led to the use of wireless circuits in most today electronicdevices This progress also caused the development of micro sensors These micro sensors have the ability todo numerous senses in things like voice recognition for sensing the earthquake As well as it has providedthe collection of information in remote areas and places that are not suitable for human explorations Therefore recent advances in fabrication of small scale integrated circuits in one hand and development ofwireless communications technology on the other hand have created great motivation for researchers andengineers in the field of research and design of sensor networks According to the development of wireless sensor networks creation of simple and efficientcommunication with low power consumption and low cost between sensor nodes is an important and vitalissue In most of these types of networks battery is used as an energy source As changing the battery in ashort time interval is impossible or costly in this type of networks life of node comes to end with completionof battery energy So in order to extend the lifetime of the network it is required to manage thecommunication of nodes with each other and their energy consumption by using an appropriate protocol That is why the subgroup 4 started working with similar purpose in Commission IEEE 802 15 that undertookthe task of standardization in the field of personal wireless networks Efforts of subgroup 4 from theCommission IEEE 802 15 led to provide IEEE 802 15 4 standard for two layers of PHY and MAC and thementioned Union s efforts in 2004 led to provide a set of standards based on IEEE 802 15 4 standard withbrand ZigBee Because of the capabilities and benefits such as energy management high throughput ratesand scalability IEEE 802 15 4 Protocol is a suitable options for wireless sensor networks In this protocol nodes compete with each other using the CSMA CA algorithm in order to achieve the channel and sendingtheir packs to destination The algorithm consists of several different parameters that their regulation has agreat impact on network throughput rate and nodes energy consumption The aim of this thesis is to provide a solution to reduce the power consumption of ZigBee transmitter receiver by improving the CSMA CA algorithm that is used as node in wireless sensor networks The maincauses of energy loss in a wireless sensor node is the collision of data frames because of simultaneoussending action of different nodes and CSMA CA overheads including the additional clear channelassessment Therefore two methods to remove additional clear channel assessment and a method to removecollision in wireless sensor networks with star topology and smaller than 256 nodes have been proposed inthis thesis which star topology may be a cluster of large network In methods which have been proposed foradditional clear channel assessment sending of the acknowledgement frame from the coordinator is doneonly after 192 microseconds so that the receiver does not clear up more time In the first proposed method location of the sending some data frames with a certain length is changed in Backoff in the second method one to three zero byte is added to the end of the data frame according to length of some data frames Toremove the collision a new algorithm has been proposed as a third method for slotted CSMA CA and eachnode in several specified Backoff performs the clear channel assessment to avoid a collision between dataframes

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