Bit synchronization method of weak signal satellite navigation system

• Main Authors: CHEN YINGTING, LIU HAOCHENG, WANG JIARAN, SONNY XUN GONG, WEI DONGMING, WANG FENG, LING YONGQUAN
• Format: Patent
• Language: English
• Published: 02.09.2015
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASURING; PHYSICS; RADIO DIRECTION-FINDING; RADIO NAVIGATION; TESTING

The invention discloses a bit synchronization method of a weak signal satellite navigation system. The method includes the steps: reading the 1ms coherent integration values of an I branch output by a tracking channel, and cycle numbering from 1 to 20 is carried out; calculating the difference between a current ms and a previous 1ms, obtaining the absolute value of a result and grouping accumulation is performed according to the current ms number; and finding the number with the highest accumulated value after multiple cycle periods, and thus the position of a bit edge can be determined. The bit synchronization method of the invention fully utilizes amplitude and symbol information provided by coherent integration data, and is capable of determining the position of a bit edge more accurately and quickly compared with a conventional bit synchronization method that only utilizes coherent integration value symbol information. The method is especially suitable for occasions with fast changes in signal intensity, enables quick bit synchronization of a navigation receiver to be achieved in a complex environment, and therefore achieves a positioning function more quickly.