Code Generation Scheme and Property Analysis of Broadcast Galileo L1 and E6 Signals

摘要

In this paper, we decode the PRN codes of the L1 and E6 signals broadcast by the Galileo GIOVE-A test satellite. We apply the 45.7 m Stanford SRI Dish and the 1.8m dish of the Stanford GNSS Monitor System to receive the satellite signal. The received data are processed in a chain of wiping off carrier, Doppler offset, Binary Offset Carrier (BOC) and navigation bits. Two code sequences are revealed in each frequency band, L1-B, L1-C, E6-B and E6-C. The L1 signals have the chip rate of 1.023 Mbps. The L1-B primary code has a period of 4 msec with 4092 bits. The L1-C primary code lasts 8 msec, and has 8184 bits. L1-B has navigation data modulated on its primary code, while L1-C has 25 bits of secondary code, which extends the whole L1-C code period to 200 msec. The E6 signals' chipping rate is 5.115 Mbps. The E6-B code is 5115 bits long and carries