XPSK: A New Cross-Correlated Phase-Shift Keying Modulation Technique

摘要: A new modulation technique, cross-correlated phase-shift keying ( XPSK ), is introduced. a band-limited offset QPSK technique which has an almost constant envelope. In modulators, controlled amount of cross correlation between the in-phase I ) and quadrature Q channels reduce envelope fluctuation Of intersymbol-interference jitter-free OQPSK (IJF-OQPSK) scheme, introduced by Feher et al. [1], [2], from 3 dB to approximately 0 dB, thus further improving performance IJF-OQPSK systems in nonlinear radio [7], [14]. It shown that baseband signal modulator, P_{e} = f(E_{b}/N_{0}) performance, spectral characteristics nonlinearly amplified (hard-limited or saturated) tamed frequency modems (TFM) are practically same. The demodulator conventional demodulator, TFM requires somewhat more complex processor. For this reason, approach may lead significant hardware cost savings, particularly point-to-multipoint distribution such as broadcast systems. Simulation results for linear (saturated amplifier) operated adjacent-channel interference environment (in addition thermal noise) presented. Measurement performed on 128 kbit/s rate hardware-prototype modem also reported. Experimental eye diagram power spectrum density measurement close agreement with computer simulation results.