Patent ID: 8767815
Filing Date: 2014-07-01
Classification: G01S,H04L

Abstract:
1. A radio frequency (RF) receiver for a pulse-position modulated signal received with unknown center frequency offset and preceded by a preamble consisting of a sequence of at least 4 pulses with known pulse spacing, the receiver comprising: a linear RF front end configured to sense a signal with a center frequency uncertainty at least equal to one half of the bandwidth of the pulses and output a digital sample stream with a sample rate greater than or equal to twice the pulse bandwidth plus maximum center frequency uncertainty based thereon; one or more processing devices; and one or more storage devices coupled to the one or more processing devices and including instructions which, when executed by the one or more processing devices, cause the one or more processing devices to detect the preamble by 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 frequency offset corrections is a fraction of the bandwidth of the pulses, wherein a total sum of all the frequency offsets span a range for the center frequency uncertainty, wherein to perform each preamble sequence correlation the one or more processing devices are configured to: