ملخص: The application of multilevel frequency-shift keying/frequency-hopping spread-spectrum multiple access (MFSK/FH-SSMA) to wireless systems has been receiving attention recently. Most studies on MFSK/FH-SSMA wireless systems so far assume to support only one type of medium. A flexible support of multimedia services in future wireless systems is expected. However, the use of conventional "fixed-length FH patterns alone cannot serve these multirate multimedia wireless systems. In this paper, a family of double-length fixed-weight generalized prime hopping patterns is reviewed. These FH patterns have cross correlations of no greater than one in order to minimize mutual interference and are well suited for wireless systems with double-media services. The performances of the prime hopping patterns and conventional random hopping patterns in MFSK/FH-SSMA wireless systems over Rayleigh fading and additive white Gaussian noise (AWGN) channels are analyzed and compared for one type of medium first and extended to two types of media. Our results show that the proposed scheme performs better than the conventional one with random hopping patterns in both nonfading and fading channels.

لغة: إنجليزية