Continuous phase modulation: Difference between revisions

Revision as of 14:16, 10 September 2007

Revision as of 02:50, 15 October 2007

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'''Continuous phase modulation''' ('''CPM''') is a method for [[frequency modulation|modulation]] of data commonly used in [[wireless modem]]s. In contrast to other coherent digital [[phase- modulation]] techniques where the carrier phase

abruptly resets to zero at the start of every symbol (e.g. M-[[phase-shift keying|PSK]]), with CPM the carrier phase is modulated in a

continuous manner. For instance, with [[QPSK]] the carrier instantaneously jumps from a sine to a cosine (i.e. a 90 degree phase shift) whenever one of the two message bits of the current symbol differs from the two message bits of the previous symbol.