Spread spectrum communication system
US4112372A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1977 |
| Grant date | Sep 5, 1978 |
| Priority date | — |
| Expiry date | Jan 11, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/216
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An improved spread spectrum communication system having a transmitter subsystem and a receiver subsystem is disclosed. The transmitter subsystem comprises a data source of 50 bps rate which is modulo-2 added to a C/A (clear/acquisition) code of 1,023K chips/sec in an EXCLUSIVE OR gate, phase modulated on a carrier signal at about 154 f.sub.o where f.sub.o = 10.23 MHz in a phase shift keying modulator and transmitted. The receiver subsystem comprises an antenna for receiving the phase modulated signal, a plurality of filter/amplifier mixer stages for reducing the phase modulated signal to baseband, an in-phase CCD matched filter channel and a quadrature phase CCD matched filter channel for determining the presence of the C/A code and the phase of the incoming C/A code for synchronizing a replica of the C/A code with the incoming C/A code, a mixer for beating the replica C/A code signal with the C/A code signal, a Costas loop for automatic phase control, a sampler for sampling the baseband signal, an integrator for integrating the sampled signals, and a clocked comparator for comparing the integrated signals with a zero voltage at a 50Hz rate to demodulate the data code. Two embodime…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.