Amazon.com, Inc.
Wireless transmitter/receiver architecture for low-power wide area networks

Abstract:

The present disclosure relates to sampling wireless signals received at a receiver. Subsets of the digital samples are multiplied by a Pseudo-Noise (PN) code to generate tone signals. A pattern of tone signals may indicate the presence of a repeating preamble. This may be used to locate a payload that follows the preamble. A tone signal of a payload may be decoded by multiplying a subset of the digital samples with the PN code to generate a tone signal. The tone signal may be transformed into the frequency domain to identify a frequency component having an energy level above a threshold. Using the frequency component, the payload is decoded. By structuring a packet as a series of PN-code modulated tone signals, packets received from different sources may be differentiated even when they arrive at overlapping points of time. This allows for a larger transmitting capacity in a network.