Method and apparatus for controlling a biphase modulation to improve autocorrelation in pseudorandom noise coded systems
US5646627A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1996 |
| Grant date | Jul 8, 1997 |
| Priority date | — |
| Expiry date | Jan 30, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/288
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention relates to a method and apparatus for controlling a biphase modulator (602, 702) to improve autocorrelation in pseudorandom noise coded systems. The biphase modulator modulates a carrier frequency with one of two phase states responsive to a pseudorandom noise (PN) binary code sequence. The spectrum (610, 710) at the output of the biphase modulator comprises a plurality of spectral lines separated by the code repetition frequency, including a center spectral line (611, 711) and at least one adjacent spectral line (612-615, 712-717). The magnitude of the center spectral line is measured and compared to a reference to produce a control signal which is responsive to the magnitude of the center spectral line. This control signal is supplied to the biphase modulator for maintaining a predetermined magnitude of the center spectral line thereby achieving a desired spectrum output and improving autocorrelation of the system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.