Combining Kalman Filtering with ZigBee Protocol to Improve Localization in Wireless Sensor Network

Algorithm 1

Localization algorithm RVI with LQI measurements and a co-operative approach.

Estimated location algorithm

 // For 𝑆𝑒𝑛𝑠𝑜𝑟_𝑖, 𝑘  𝐴𝑛𝑐ℎ𝑜𝑟𝑠 and 𝑝𝑁𝑜𝑑𝑒𝑠

 INPUT: link quality indicator 𝐿_𝑖, estimated distances 𝑔_𝑖, beacon locations 𝑆_𝑘

 OUTPUT: estimate of 𝑋_𝑗

 Initialization: 𝑋₀=𝑋_𝑊𝐶=∑^𝑘_𝑖=1𝑤_𝑖𝑆_𝑖∑^𝑘_𝑖=1𝑤_𝑖

 Normalization: 𝑔_𝑖,𝑗=𝑆_𝚤𝑋_𝚥∑^𝑘_𝑖=1𝑆_𝚤𝑋_𝚥

 while  𝑋_𝑗+1−𝑋_𝑗<𝐶_th and 𝑉_𝚥−1⋅𝑉_𝚥<0  do

     for  all 𝐴𝑛𝑐ℎ𝑜𝑟_𝑘 and 𝑁𝑜𝑑𝑒_𝑝  do

     if  𝑁𝑜𝑑𝑒_𝑝 is visible to 𝑆𝑒𝑛𝑠𝑜𝑟_𝑖  then

     𝑉_𝑗=𝑐Δ_𝑗Δ_𝑗𝑠_𝑖𝑗>𝑁_init𝑒𝑡Δ_𝑗Δ<𝑐with_𝑗=∑^𝑘_𝑖=1𝑔_𝑖−𝑔_𝑖,𝑗𝑆_𝑖𝑋_𝑗𝑆_𝑖𝑋_𝑗Δ_𝑗𝑠𝑖𝑛𝑜𝑛

     end if

     end for

     𝑋_𝑗+1=𝑋_𝑗+𝑉_𝚥

 end while