A Binary Noncoherent Frequency-Shift-Keying (NCFSK) Multiple-Message One-Shot Radio Transmission System that Uses a Sync Preamble

A binary noncoherent frequency-shift-keying (NCFSK) multiple-message one-shot radio transmission system is discussed where the receiver has no prior knowledge of the possible starting time of transmission. In this system each transmitted signal has a common preamble for signal acquisition and self-synchronization purposes. System design procedures are described for allowable frequency of occurrence of false alarm and probabilities of a miss and a message error specified for the system. In addition, the probability of premature response (i.e., the probability that the receiver makes an affirmative decision on acquisition of the signal when the sync preamble is only partially received) is taken into account. It is shown that the selection of sync preamble codes from randomly generated binary sequences can be a highly attractive approach. A simple, but very meaningful, criterion is suggested for aid in such a selection. The system described here can be used as a radio warning system and also as a selective call or selective interrogation system.