Patent · US Expired

Method for demodulating information in a communication system that supports multiple modulation schemes

US6125148A · kind A · utility

105Cited by
12References
43Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 29, 1997
Grant dateSep 26, 2000
Priority date
Expiry dateAug 29, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L27/0008
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

A method of demodulating voice or data and control information in systems that support multiple modulation schemes modulates voice or data using a first linear modulation scheme, such as 16QAM modulation scheme, and modulates control information using a second linear modulation scheme, for example, QPSK modulation scheme, that has the same symbol rate as that of the first modulation scheme. The first linear modulation scheme has a higher modulation level than the second linear modulation scheme. Information modulated using the second linear modulation scheme, which uses a reduced signal set of the first linear modulation scheme, are demodulated using the same demodulator that is used for demodulating information modulated using the first linear modulation scheme. Also, in-band signalling information within a traffic channel, such as stealing flags, are modulated using the second modulation scheme.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.