Research On Information Error-correcting In Wireless Sensor Networks

With the development of the technologies in Micro-Elector-Mechanical Systems(MEMS),ireless communication and digital electron,Wireless sensor network is proposed.Owing to features of self-configuring and dynamic topology,wireless sensor network can be used in any fields,such as security and surveillance,control,actuation and maintenance of complex stems,and monitoring of indoor and outdoor environments.Sensor networks differ from nventional network systems in many aspects like energy constrained,self-configuring and If-aware nodes.Extensive applications require senior reliability and longer life.There are mainly two kinds of error control mode.One is Forward Error Control(FEC),the other is Automatic Repeat Request(ARQ).FEC puts additional bits(i.e.redundancy) on original code with a rule,while using the redundancy,the transmitted code words would be pecked at receiver.If there are errors,then they would be corrected.The mode of ARQ,whatever,only checks errors in transmitted code,and can't correct errors.The only way to correct errors is to retransfer the information bits.The overheads caused by retransfer of bits can result in excessive data computation which can bring out more energy cons??.Therefore,we should consider the use of FEC and adapt right error correct codes to designed error control.Because of the feature of energy limited,error correct codes should focus on low complexity of algorithm.As for WSN,communication with package of fixed length,energy consumption of error control BCH-based is less 15% than that of convolutional codes.Therefore,the error control schema proposed in the text is based on Bch codes using fast decoding arithmetic designed on the basis of direct decoding and iterative decoding arithmeticGenerally,only one error control schema based FEC seems reasonable,which,however,is treasonable.The reason is the state of wireless channel is real-time.When wireless channel is good condition,it is unnecessary to use error control schema with strong correct-error ability which can cause more energy consume; by contraries,when channel state is bad,it is wrong to use correct code with low correct-error ability which can't guarantee the reliability.Consequently,owning to the real-time change of wireless channel,an adaptive error control schema is proposed.Error correct codes with different ability of correct errors are used.At the same time,a fast decoding algorithm with low complexity is used in the error control schema.The result of the schema shows that not only reliability is provide with,but also less energy is consumed.