Data transmission by frequency-hopped multilevel frequency shift keying

The possibility of utilizing frequency-hopped multilevel frequency shift keying (FH-MFSK) techniques for data transmission corrupted by additive white Gaussian noise (AWGN) is discussed. FH-MFSK is one of the many techniques used in spread spectrum systems and is a combination of frequency-hopping and time-hopping. In this system many users share a common frequency band using code-divisionmultiplexing. Each user is assigned an address and the message is modulated on to the address. The receiver, knowing the address, decodes the received signal and extracts the message. A microprocessor supervised experimental FH-MFSK system has been constructed and used to perform error-rate measurements in the presence of AWGN with deleted and delayed sample effects. Its capability for multi-user applications has been determined theoretically. The results show that FH-MFSK is a suitable technique for data transmission in the presence of AWGN.