GIOVE B L1 Codes

GIOVE-B L1 Code Generators

Grace Gao and Per Enge

We have decoded two codes on L1 GIOVE-B. These are the L1-B and L1-C code. The codes are different from the Galileo ICD. This is not unusual as GIOVE-B is not an operational Galileo satellite.

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•Results:

–The code is a linear code (13 stage Gold codes)
–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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L1-B code: 4092 bits, 4ms, 13 stage Gold code

Polynomial 1: X¹³+X¹⁰+X⁹+X⁷+X⁵+X⁴+1

Polynomial 2: X¹³+X¹²+X⁸+X⁷+X⁶+X⁵+1

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

Initial state 2: [1 0 0 1 1 1 1 1 1 1 1 0 0]

L1-C code: 8184 bits, 8ms, 13 stage Gold code

Polynomial 1: X¹³+X¹⁰+X⁹+X⁷+X⁵+X⁴+1

Polynomial 2: X¹³+X⁴+X³+X+1

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

Initial state 2: [1 1 1 1 1 1 1 1 1 1 1 1 1]

LINKS

To details on the SGMS, CONTINUE

To GIOVE-B E5 Code, CONTINUE

To GIOVE-A L1 OS Code, CONTINUE

To GIOVE-A E6 Code, CONTINUE