Research On A Coexistence Method For Heterogeneous Wireless Networks Based On Adaptive FEC And ARQ

With the rapid development of wireless broadband communication technology,the users' demand for precious and scarce spectrum resources on speed and bandwidth becomes greater and greater.Therefore,the scarcity of spectrum resources is severer.Fortunately,the sharp development of cognitive radio technology provides an effective solution for the spectrum scarcity and the coexistence of different wireless communication networks.The widespread use of cognitive radio makes it possible for a variety of wireless communication technologies to share the same frequency.Also the coexistence between licensed and unlicensed users becomes true.Many wireless users of different communication technologies share a same spectrum by adopting cognitive radio technology,thus forming a large wireless heterogeneous network.Based on the coexistence of ZigBee and WiFi in 2.4GHz,this paper propose a coexistence method based on adaptive Forward Error Correction and Automatic Repeat reQuest.After applying the method in ZigBee communication by USRP devices,the method effectively improves the ZigBee communication quality under the WiFi interference.The main works are organized as follows:(1)A coexistence model of ZigBee and WiFi in the real laboratory environment is established.The research in this paper is oriented the actual laboratory WiFi environment and observes the packet loss rate and packet error rate of the node-to-node ZigBee communication.And the coexistence model of ZigBee and WiFi is built based on the Actual experimental data.(2)Research on a coexistence method for wireless heterogeneous network based on adaptive FEC and ARQ.The coexistence methods for ZigBee and WiFi based on FEC technology and ARQ technology are studied respectively.Before sending packets,the WiFi interference in current channel is measured by energy sensing.The payload of ZigBee packets is coded adaptively to reduce the packet error rate.This can improve the coding efficiency and reduce data redundancy.Then the lost packets are waited and retransmitted by adaptive retransmission,which can lower the packet loss rate at the retransmission cost as little as possible.(3)The implementation and performance analysis of the adaptive FEC and ARQ coexistence method on USRP platform.This work uses the USRP devices modify the original simplex ZigBee communication and realize a half duplex node-to-node ZigBee communication with ACK and retransmission mechanism.Then the proposed coexistence method is implemented to solve the coexistence problem between ZigBee and WiFi through the devices.Finally,the method is proved to be effective.And the preformance of the method is analyzed.