ملخص: In this paper, we newly analyze the effect of phase noise in the frequency synthesizer on the performance of fast frequency-hopping (FFH)/M-ary noncoherent frequency-shift keying (M-NCFSK) system. The symbol-error probability (SER) of the frequency-hopping spread-spectrum (FHSS) system is derived when the noncoherent FSK demodulation with the square-law detector is considered. Also, the effect of phase noise on the performance of the FFH/M-NCFSK system is analyzed in terms of phase noise power spectrum and frequency-hopping spacing, as well as the diversity level. The required signal-to-noise ratio (SNR) to meet P<subscript>s = 10<superscript>-<superscript>3 is about 11.8 dB when the standard frequency deviation is about 31.623 kHz and the frequency-hopping spacing in the FFH/2-NCFSK system is 400 kHz. So, it is found that there is about 0.8-dB power penalty than the phase noise-free system. Similarly, there is about 0.7-dB power penalty in the FFH/4-NCFSK system. SER performance is changed with the standard frequency deviation, but SER is nearly independent of the modulation level. As the diversity level is increased from 1 to 4, frequency diversity effect is trivial in the lower SNR below 6 dB, but is considerably improved in the higher SNR.

لغة: إنجليزية