Performance Evaluation and Interpretation of Unfiltered Feher-Patented Quadrature-Phase-Shift Keying (FQPSK)

摘要: A new interpretation of unfiltered Feher-patented quadrature-phase-shift keying (FQPSK) is presented that readily identifies a means for spectral enhancement the transmitted waveform as well an improved method reception. The key to these successes replacement half-symbol-by-half-symbol mapping originally used describe FQPSK by symbol-by-symbol operation combined with memory. advantages such are twofold. In particular, original scheme can be modified potential slope discontinuity at boundary between half symbols avoided without sacrificing “constant” envelope property waveform, and, furthermore, memory receiver employed improve error-probability performance relative previously proposed detection methods. analysis in this article does not include other versions FQPSK-B, which currently being considered military application.