Reduction of the error floor of MSK by nonlinear frequency discriminator

Research output: Contribution to journalArticle


We consider the error floor of binary frequency-shift keying (FSK) due to intersymbol interference in time-dispersive mobile radio channels, with a limiter-discriminator-integrator detector. The errors are caused by bursts in the instantaneous frequency. We propose and verify that a nonlinear frequency discriminator can achieve zero error floor for pure FSK by clipping off these bursts. For filtered FSK, the error floor is not completely removed, but strongly reduced - typically by one or two orders of magnitude. The tighter the filtering, the less effective this nonlinearity is. The nonlinear discriminator can also be used in conjunction with adaptive sampling.


  • Andreas Molisch
  • R Petrovic
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Electrical Engineering, Electronic Engineering, Information Engineering


  • discriminators, dispersive channels, frequency shift keying, intersymbol interference, minimum shift keying, mobile radio, signal detection
Original languageEnglish
Pages (from-to)1101-1107
JournalIEEE Transactions on Wireless Communications
Issue number5
Publication statusPublished - 2003
Publication categoryResearch