Perpustakaan Digital ITB

The paper is concerned with the bit error rate (BER) performance of multiple hops/ symbol fast-frequency-hopped spread-spectrum multiple-access (FFH-SSMA) systems operating through an indoor radio multipath Rayleigh fading channel. M-ary frequency-shift-keying (MFSK) modulation with noncoherent square-law envelope demodulation and Reed-Solomon (RS) coding is considered. Results obtained in this study show that an FFH-SSMA system is not sensitive to the changes in the number of paths. Employing RS coding with an increased number M of MFSK signals yields a significant improvement in BER performance. Assuming a given system bandwidth, using a single hop per symbol is the best solution when the multiaccess interference can be large. Using several hops per symbol is more advantageous when the multiaccess interference is small.