Hybrid DS-FH packet acquisition for frequency hopped random multiple access

Instead of decreasing pulse duty cycle of the synchronization pulse of FH random multiple access (RMA) to decrease the multiple access interference between users in the acquisition stage, we use a PN generator to spread the modulated data before going to the hopped carrier, the transmitter of each user has the same PN generator of the other users but they differ in initial state of shift registers of the PN generator, and this initial state is known only to the desired receiver, so we can use the auto correlation property of the PN generator to overcome the problem of multiple access interference. The results show that our scheme is better than the FH packet acquisition scheme that depends on decreasing pulse duty cycle to decrease multiple access interference.