Novel modulations, based on the binary chirp waveform, are proposed as generalizations
of binary offset carrier (BOC) schemes. They allow enhancement
of the performance of Global Navigation Satellite System (GNSS) receivers
affected by Gaussian noise, multipath, and interference. Adequate selection
of parameters enables efficient use of the channel bandwidth to enlarge the
Gabor bandwidth. Schemes characterized by autocorrelations with small secondary
peaks are obtainable, permitting minimization of the probability of code
acquisition with incorrect code phase and reducing the probability of false
code-locks in tracking mode. Increased robustness to multipath and interference
also occurs. These advantages make the proposed modulation schemes
promising candidates for future navigation signals.