Complementary linear feedback shift registers for generating advance timing masks
OwnerDavid Meyerinventor
Life of this patent
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Abstract
A mask required to generate a time-offset version of a PN code may be generated by constructing a Galois linear feedback shift register (LFSR) that is complementary to a Fibonacci LFSR that generates the PN code, clocking the Galois LFSR a number of times equal to the time offset, and reading the state of the Galois LFSR, which is the desired mask.
Claims21
A method for generating a linear feedback shift register (LFSR) mask for a first LFSR, comprising:
- providing for a second LFSR that is complementary to the first LFSR,
- providing for clocking the second LFSR a number of times equal to a desired timing advance, and
- providing for using a state of the second LFSR as the LFSR mask for the first LFSR.
A circuit configured to compute at least one mask for a first LFSR, comprising:
- a second LFSR that is complementary to the first LFSR,
- a shift-value input to the second LFSR, the shift-value input configured for clocking the second LFSR a number of times equal to a desired timing advance, and
- a state input to the first LFSR configured for receiving a state of the second LFSR as the at least one mask for the first LFSR.
A computer-readable memory configured to compute at least one mask for a first LFSR, said computer-readable memory configured for implementing the steps of:
- providing for a second LFSR that is complementary to the first LFSR,
- providing for clocking the second LFSR a number of times equal to a desired timing advance, and
- providing for receiving a state of the second LFSR as the at least one mask for the first LFSR.
Dependencies are inferred from the claim text.