CDMA modulation and demodulation method reducing interference and a communication system using the same
US6009074A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1997 |
| Grant date | Dec 28, 1999 |
| Priority date | — |
| Expiry date | Jul 24, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/707
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A CDMA (Code Division Multiple Access) modulation and demodulation method and a communication system using the same which simultaneously transmits a pilot signal and a data signal through the same channel, thereby being capable of not only greatly the complexity of its transceiver, but also achieving an improvement in performance where a large number of multipaths are used. The method includes the steps of (a) generating a pilot signal and a transmission data signal; (b) spreading the pilot signal and the transmission data signal, by multiplying the pilot signal by an inphase pseudo noise sequence and by multiplying the transmission data by a quadrature pseudo noise sequence, respectively; (c) generating an inphase signal and a quadrature signal, by multiplying the spread pilot signal by an inphase walsh data sequence and by multiplying the spread transmission data by a quadrature walsh data sequence, respectively; (d) modulating the inphase signal and the quadrature signal, by multiplying the inphase signal and the quadrature signal by carrier signals; and (e) transmitting a composite signal created by adding the modulated inphase signal to the modulated quadrature signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.