LDPC Code Research In Wireless Sensor Networks

Wireless sensor networks are the focus of wireless communications research today. It can be widely used in various fields. As the wireless sensor networks is much easier to be interference than cable sensor networks ,in many field such as battlefield, medical, mining and other areas need high accuracy of the data, so it?s necessary for wireless sensor networks use effective error control. LDPC encoding and decoding technology has good performance in error correction and high operation efficiency. So it is very suitable for wireless sensor networks.Wireless sensor network is deployed by a number of sensor nodes which computing capacity, storage capacity and energy supply is limited. My LDPC codec design fully consider the characteristics of wireless sensor networks, the use of variable code length, code rate and decoding methods in order to meet different circumstances in different areas of need. LDPC encoder uses a base matrix expansion method can be generated by simple arithmetic, It can effectively saving hardware resources. In the decoding algorithm, I design three methods such as hard-decision decoding algorithm, sum-product decoding algorithm and the minsum decoding algorithms. Through compare with different code length, code rate and decoding methods, we can see the minsum decoding algorithm using a short code has the same performance with sum-product decoding algorithm. And the minsum decoding algorithm is simpler than sum-product decoding algorithm,so it is more suitable for use in the wireless sensor networks.LDPC codes has very good performance in error correction, to a certain bit error rate requirements, it can reduce the node transmit power through the encoding and decoding technology。Known by calculating the bit error rate requirements for the 10-4 condition, using (372,168) LDPC codec,the energy efficiency across the codec system is increased 40%-50% than the system which has no codec, and the between node one hop distance increased by 20% -30%, effectively improve the network stability. When the channel quality is certain,the LDPC codes can achieve higher transfer rates.In summary, the use of LDPC codec in wireless sensor networks can meets the system bit error rate requirements, and more effective to reduce the node transmission power, improved energy efficiency, expanding the coverage of the node. Provide a more broad application prospects.