The Research And Application Of FEC In IEEE 802.15.4 Network

Today,the Internet of things was officially become as one of the five emerging strategic industries,its wide development prospects have been caught the attentions of the major industries.The wireless sensor network is one of the most important basic technologies of Internet of things.Now,The WSN based on IEEE 802.15.4 is widely used,for example,In intelligent industry,intelligent transportation can see its application.But at low channel-quality environment(for example IWSN),the MFA and El effect is more obvious than conventional environment which will bring more package error during transmission.But at the IEEE 802.15.4 protocol,there is no error correct function,so the original ARQ mechanism will probably bring more retransmission,which will cause network congestion and delay of effective transmission.In order to solve those problems,this thesis will bring FEC technique to the original IEEE 802.15.4.By comparing common channel codec in theory and engineering,finally decided to use RS(Reed-Solomon)code to correct error.The soft RS code can be directly implemented in the existing embedded platform.Meanwhile,in order to increase the system resource utilization efficiency,the thesis designs the adaptive correct method based on the RS code,which can change the correction ability adaptive with the environment.This method is made up by several modules and the thesis analyses the design and the implementation of these modules in detail.Then the thesis tests the RS code and the adaptive error correction method at the specific embedded platform.The result shows the adaptive correct method has the ablity of change with the environment and can reduce the packet error rate in bad environment.At the same time,in view of the LQI value in different test environment,the test result is analyzed.