Asynchronous digital correlator and demodulators including a correlator of this type
US4933952A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 4, 1989 |
| Grant date | Jun 12, 1990 |
| Priority date | — |
| Expiry date | Apr 4, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J13/0025
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A demodulator to demodulate a complex signal formed by two carriers, in quadrature, the spectrum of which is spread by a pseudo-random signal, and which are modulated by an M-ary, Walsh, code comprises: PA1 a chain of registers to store 256 bits of a pseudo-random signal; PA1 a multiplexer to temporally multiplex the processing of the two carriers; PA1 a chain of correlation macro-cells having a systolic structure enabling temporal multiplexing and having intermediate outputs providing for partial correlation values on 16 chips; PA1 a device for the computation of linear combinations of the functions of partial correlation, to compute two functions of correlation corresponding to two carriers for each M-ary code; PA1 a demultiplexing and computation device to compute the module of the function of correlation for each of the Walsh codes which may modulate the signal to be demodulated; PA1 a device for the selection of the greatest value of the correlation functions and for the selection of the corresponding piece of data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.