HU Yi, SONG Maozhong, MENG Bin. Analysis and Improvement of the MAP Algorithm for NavigationSatellite Convolutional Codes Decoding[J]. Geomatics and Information Science of Wuhan University, 2014, 39(3): 267-270. DOI: 10.13203/j.whugis20120053
Citation:
HU Yi, SONG Maozhong, MENG Bin. Analysis and Improvement of the MAP Algorithm for NavigationSatellite Convolutional Codes Decoding[J]. Geomatics and Information Science of Wuhan University, 2014, 39(3): 267-270. DOI: 10.13203/j.whugis20120053
HU Yi, SONG Maozhong, MENG Bin. Analysis and Improvement of the MAP Algorithm for NavigationSatellite Convolutional Codes Decoding[J]. Geomatics and Information Science of Wuhan University, 2014, 39(3): 267-270. DOI: 10.13203/j.whugis20120053
Citation:
HU Yi, SONG Maozhong, MENG Bin. Analysis and Improvement of the MAP Algorithm for NavigationSatellite Convolutional Codes Decoding[J]. Geomatics and Information Science of Wuhan University, 2014, 39(3): 267-270. DOI: 10.13203/j.whugis20120053
1College of Electronic Information Engineering,Nanjing University of Aeronautics & Astronautics,Nanjing 210016,China;2The Academy of Satellite Application,China Aerospace Science and Technology Corporation,Beijing 100086,China
Funds: The Open Research Fund of the Academy of Satellite Application,No.20121512.
Objective Computers may encounter the problem of numerical instability and output a wrong bit errorrate(BER)when decoding navigation satellite convolutional codes with the maximum a posterioriprobability(MAP)algorithm.Subsequently,this will affect the validity and the accuracy of the posi-tioning results.To address this problem,first a detailed analysis was executed.Based on this analy-sis,an improved MAP algorithm normalized with the maximum state metric is proposed,thus thequestion of numerical instability can be solved while still maintaining the original algorithm’s optimalperformance.Simulations further validate the effectiveness of this algorithm’s improvement.
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