A burst GFSK-modem for wireless LAN systems
幸二 松山, Shigeyuki Yoshioka, M. Shimizu, Nobuaki Aoki, Y. Tozawa · 2002
In this paper, we present a GFSK modem for use in spread spectrum wireless LAN systems. The proposed digital GFSK modem includes open loop automatic frequency control (AFC) to capture burst data completely. The transmission rate is 1 Mbps. It uses a frequency discriminator for detection and an A/D converter for digital processing. We explain the configuration and the operation of the GFSK modem and show the experimental BER and AFC performance results. The AFC's performance was evaluated for frequency offsets in both static and Rayleigh fading environments. We found that our demodulator with AFC synchronized within 8 symbols when the frequency shift was more than /spl plusmn/240 kHz. A digital GFSK modem circuit can be fabricated as a digital integrated circuit using only 3,000 gates.