An electronic circuit comprises a randomizing bit generator configured to
generate a randomizing bit sequence based on a sequence selection input
signal. The randomizing bit generator includes a counter operable to
provide an individual starting count for the randomizing bit sequence and
a parity generator responsive to an output of the counter. The circuit
further comprises a pseudo-random number generator responsive to the
randomizing bit generator. The pseudo-random number generator is operable
to provide at least one pulsed signal based at least in part on the
random bit sequence. The electronic circuit is operable to substantially
eliminate interference in a series of pulsed signal transmissions
comprising the at least one pulsed signal from each of two or more
navigation devices, where each of the pulsed signals from each of the
navigation devices is separated by an automatically adjustable time
interval.