Design Of Concatenated Polar Codes And Performance Analysis In Wireless Sensor Networks

In the current study of the fifth generation mobile communication(5G)standards,the support of the Internet of Things(IoT)is an important aspect.As an important part of the Internet of things,wireless sensor networks(WSNs)are characterized by self-organization,large-scale,and stringent energy constraint.Among these factors,the stringent energy constraint is the most critical aspect.So the primary goal of designing the wireless sensor networks is to reduce energy consumption of the nodes.The key to reduce the energy consumption of the nodes is to minimize the bit error rate that the nodes can achieve under given channel conditions.Forward error correction(FEC)coding is an important method to reduce bit error rate.Due to the energy consumption and the performance reasons,finding a suitable FEC coding is essential for wireless sensor networks.Polar codes are theoretically proven to be capable of realizing the channel capacity for binary symmetric channels.Polar codes not only have good bit error rate performance,but also have very low encoding and decoding complexity.Polar codes have been a very active research topic worldwide.In this thesis,the principle of encoding and decoding of polar codes is introduced,and the bit error rate of different code lengths,different code rates and different decoding algorithms are simulated and analyzed.The non-systematic polar codes are the original form of polar codes.Systematic polar codes not only maintain the low complexity of non-systematic polar codes,but also improve the bit error rate performance.In order to reduce the complexity of the systematic polar codes,this thesis provides a concatenated scheme of BCH code and systematic polar codes,and proves the superiority of the concatenated scheme by simulations.In addition,this thesis analysis the perfomance of polar codes in wireless sensor networks.The coding methods of the ZigBee protocol,the BlueTooth protocol and the 802.11g protocol are compared with polar codes.Then,other coding methods(such as Turbo codes,LDPC codes,etc.)are also compared and analyzed.The results show that under the same conditions,the low energy consumption characteristic of polar codes can prolong the lifetime of the wireless sensor networks,or make the energy consumption of the nodes lower.Through studies in this thesis,polar codes are found to be a good coding choice suitable for wireless sensor networks.