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Modern Geomatics Technologies and Applications

The results of the G 1 polynomial code are fed as input to the second G 2 polynomial. In addition, Figure 7 show
combinations of GPS satellites for C/A code generation that there is a unique combination for each satellite to generate the C/A
code. Figure 9 shows the output combinations of the G1 and G2 polynomials to generate a unique code for each satellite.

Figure 9. The combinations of the G1 and G2 outputs to generate a unique C/A code for each GPS satellite.
Table 4. C/A PRN code Generation for SV#01 and SV#32

( ) ∩ ( )

Output Output G 2 for Output G 2 for C/A PRN code for C/A PRN code for
G 1 SV#01 SV#32 SV#01 SV#32

Step_01 1 0 0 1 1

Step_02 1 0 0 11 11

Step_03 1 0 1 111 110

Step_04 1 1 0 1110 1101

Step_05 1 1 0 11100 11011

Step_06 1 0 0 111001 110111

Step_07 1 1 0 1110010 1101111

Step_08 1 0 0 11100101 11011111

Step_09 1 1 0 111001010 110111111

Step_10 1 1 1 1110010100 1101111110

Step_1023 1 0 1 1110010100…….01 1101111110…10

As shown in Table 4, the C/A PRN codes are generated for the two satellites No. 1 and 32 GPS in ten steps, which are
different and unique to all satellites. These codes are generated and repeated in 1023 strings of PRN code per microsecond for
each GNSS satellite. Afterward, The GPS carrier’s waves could have been modulated in a variety of ways to carry the binary
10