A method of processing a pulse-position modulated signal, the method comprising: receiving the pulse-position modulated signal, the pulse-position modulated signal comprising an unknown center frequency offset, an expected preamble and a subsequent pulse-position modulated message, the expected preamble comprising at least 4 pulses with known pulse spacing; generating a digital sample stream from the received pulse-position modulated signal, wherein the digital sample stream has a sample rate greater than or equal to twice a bandwidth of a pulse of the expected preamble plus a maximum center frequency uncertainty between a transmitter of the pulse-position modulated signal and a receiver of the pulse-position modulated signal, wherein the maximum center frequency uncertainty is at least equal to one half of the bandwidth of the pulses of the expected preamble; performing multiple preamble sequence correlations in parallel, wherein each of the multiple preamble sequence correlations operates on a version of the digital sample stream having a different frequency offset, wherein spacing between the different frequency offsets is a fraction of the bandwidth of a pluse of the expected preamble, wherein a total of all the different frequency offsets span a range for the center frequency uncertainty, wherein each preamble sequence correlation of the multiple preamble sequence correlations includes: producing a first output data stream by filtering the digital sample stream with a first matched filter (602, wherein the first matched filter has a first impulse response matched to a first duration and sequence of pulses in an earlier half of the expected preamble; producing a second output data stream by filtering the digital sample stream with a second matched filter, wherein the second matched filter has a second impulse response matched to a second duration and sequence of pulses in a latter half of the expected preamble and determine that a sequence of pulses in the received pulse-position modulated signal match the expected preamble based on when the first output data stream and the second output data stream are above a minimum trigger level at the same time. receiving the pulse-position modulated signal, the pulse-position modulated signal comprising an unknown center frequency offset, an expected preamble and a subsequent pulse-position modulated message, the expected preamble comprising at least 4 pulses with known pulse spacing; generating a digital sample stream from the received pulse-position modulated signal, wherein the digital sample stream has a sample rate greater than or equal to twice a bandwidth of a pulse of the expected preamble plus a maximum center frequency uncertainty between a transmitter of the pulse-position modulated signal and a receiver of the pulse-position modulated signal, wherein the maximum center frequency uncertainty is at least equal to one half of the bandwidth of the pulses of the expected preamble; performing multiple preamble sequence correlations in parallel, wherein each of the multiple preamble sequence correlations operates on a version of the digital sample stream having a different frequency offset, wherein spacing between the different frequency offsets is a fraction of the bandwidth of a pluse of the expected preamble, wherein a total of all the different frequency offsets span a range for the center frequency uncertainty, wherein each preamble sequence correlation of the multiple preamble sequence correlations includes: producing a first output data stream by filtering the digital sample stream with a first matched filter (602, wherein the first matched filter has a first impulse response matched to a first duration and sequence of pulses in an earlier half of the expected preamble; producing a second output data stream by filtering the digital sample stream with a second matched filter, wherein the second matched filter has a second impulse response matched to a second duration and sequence of pulses in a latter half of the expected preamble and determine that a sequence of pulses in the received pulse-position modulated signal match the expected preamble based on when the first output data stream and the second output data stream are above a minimum trigger level at the same time. producing a first output data stream by filtering the digital sample stream with a first matched filter (602, wherein the first matched filter has a first impulse response matched to a first duration and sequence of pulses in an earlier half of the expected preamble; producing a second output data stream by filtering the digital sample stream with a second matched filter, wherein the second matched filter has a second impulse response matched to a second duration and sequence of pulses in a latter half of the expected preamble and determine that a sequence of pulses in the received pulse-position modulated signal match the expected preamble based on when the first output data stream and the second output data stream are above a minimum trigger level at the same time.