A coherent demodulator for fast frequency-hopping spread-spectrum signal employing an adaptive algorithm
✍ Scribed by Keiji Takakusaki; Masao Nakagawa
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 742 KB
- Volume
- 78
- Category
- Article
- ISSN
- 8756-6621
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✦ Synopsis
It has been considered impossible to demodulate a fast frequency-hopping (FFH) spread-spectrum signal coherently in a frequency selective fading channel as a result of difficulties with making the receiver local oscillator track the phase of a received signal that lacks phase continuity. This paper proposes a coherent demodulator for both FFH-PSK (phase-shift keying) and FFH-FSK (frequency-shift keying) signal employing a method in which the received signal is noncoherently downconverted and phase-adjusted by an adaptive algorithm.
Computer-simulations show that performance is better than in the case of noncoherent demodulators and that the interference-rejection effect of the adaptive algorithm produces strong protection against interferences from other CDMA users.