WAAS information from the Stanford GPS Lab

Galileo (GIOVE-A) E5 (E5a + E5b) Code Generators

Grace Gao, Jim Spilker, Dennis Akos, Sherman Lo, Alan Chen, and Per Enge

The GIOVE-A and proposed GALILEO E5 signal is composed to two signals modulated using AltBOC. These are the E5a and E5b code. Examined individually, the codes look like BPSK signals.

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•Results:

–The code is a linear code (28th order polynomial)
–Factorize obtained code generator polynomials
–The code sequence can be generated by modulo 2 addition of maximal length sequences of the factor polynomials

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E5a-A code: 10230 bits, 1ms, Gold code, 20 bit secondary code

Polynomial A1: X¹⁴+X⁸+X⁶+X¹+1

Polynomial A2: X¹⁴+X¹²+X⁸+X⁷+X⁵+X⁴+1

Initial state A1: [1 1 1 1 1 1 1 1 1 1 1 1 1 1]

Initial state A2: [1 1 1 0 1 0 1 0 1 1 1 1 1 1]

Secondary code: [1 -1 -1 -1 -1 1 -1 -1 -1 -1 1 -1 1 1 1 -1 1 -1 -1 1]

E5a-B code: 10230 bits, 1ms, Gold code, 100 bit secondary code

Polynomial B1: X¹⁴+X⁸+X⁶+X¹+1

Polynomial B2: X¹⁴+X¹²+X⁸+X⁷+X⁵+X⁴+1

Initial state B1: [1 1 1 1 1 1 1 1 1 1 1 1 1 1]

Initial state B2: [0 1 1 0 1 1 0 0 1 0 1 0 1 0]

Secondary code: [1 1 1 1 -1 1 1 1 1 -1 1 -1 1 -1 1 -1 1 1 -1 -1 1 -1 1 1 1 1 1 -1 -1 -1 1 1 1 -1 -1 -1 -1 1 -1 -1 1 1 -1 -1 1 1 -1 -1 -1 1 -1 1 1 -1 -1 -1 1 1 1 -1 1 1 1 -1 -1 -1 -1 1 -1 -1 1 1 -1 1 1 -1 -1 -1 -1 1 -1 1 -1 1 1 -1 1 -1 -1 1 -1 -1 1 -1 1 -1 1 1 1 1]

E5b-A code: 10230 bits, 1ms, Gold code, 4 bit secondary code

Polynomial A1: X¹⁴+X¹³+X¹¹+X⁴+1

Polynomial A2: X¹⁴+X¹²+X⁹+X⁸+X⁵+X²+1

Initial state A1: [1 1 1 1 1 1 1 1 1 1 1 1 1 1]

Initial state A2: [1 1 1 0 0 0 1 0 1 0 0 0 1 0]

Secondary code: [-1 -1 -1 1]

E5b-B code: 10230 bits, 1ms, Gold code, 100 bit secondary code

Polynomial B1: X¹⁴+X¹³+X¹¹+X⁴+1

Polynomial B2: X¹⁴+X¹²+X⁹+X⁸+X⁵+X²+1

Initial state B1: [1 1 1 1 1 1 1 1 1 1 1 1 1 1]

Initial state B2: [1 1 0 0 0 0 0 0 0 0 0 1 0 0]

Secondary code: [1 -1 -1 -1 1 1 1 1 -1 1 1 -1 1 1 1 -1 -1 -1 -1 1 -1 1 -1 1 -1 1 -1 -1 -1 -1 -1 1 -1 -1 -1 1 1 1 1 1 1 -1 1 1 1 -1 -1 -1 1 1 -1 -1 1 -1 -1 1 1 -1 1 1 -1 -1 -1 1 1 1 -1 -1 1 -1 -1 -1 -1 -1 1 1 1 1 1 1 -1 1 1 -1 1 1 1 1 -1 1 1 -1 1 -1 -1 1 1 1 -1 1]

LINKS

For details on how the SGMS results were verified, CONTINUE

Back to GIOVE-A L1 OS Code, CONTINUE

Back to GIOVE-A E6 Code, CONTINUE