Pulse or digital communications – Receivers – Amplitude modulation
Reexamination Certificate
2002-07-03
2009-11-03
Liu, Shuwang (Department: 2611)
Pulse or digital communications
Receivers
Amplitude modulation
C375S316000, C375S332000, C455S130000
Reexamination Certificate
active
07613253
ABSTRACT:
A method of demodulating digital data using M'ary QAM has been disclosed, comprising the steps of detecting a complex symbol vector D, establishing within which reference symbol boundaries the detected symbol vector D falls, the given reference symbol boundaries being associated with a complex reference vector R. Quadrature components (E_I and E_Q) of an error vector (E) constituting the difference between the detected vector D and the associated reference vector R are found and an error control signal (E′) as feed back signal in the demodulation stage is approximated. The influence of thermal noise in the receiver stage has been limited by a weighting and/or by noise balancing.
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Mouaki Benani, A et al, “Comparison of Carrier Recovery Techniques in M-QAM Digital Communication Systems” In: 2000 Canadian Conference on electrial and Ocmputer Engineering, Halifax, NS, Canada, Mar. 7-10, 2000, vol. 1., pp. 73+77, INSPEC Accession No. 6691171, see the whole document.
Flores Leon
Liu Shuwang
Telefonaktiebolaget L M Ericsson (PUBL)
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