Low-power, frequency-hopping, wide-area network with random medium access
AssigneeSemtech Corporation
InventorsOlivier Bernard André SELLER, Nicolas Sornin
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Abstract
A hopping spread-spectrum wireless network for IoT applications. The network includes mobile devices with unsynchronized local clocks that transmit including, in a preamble portion, a plurality of sync words, each combined with at least one instance of a sequential index. The hopping frequencies at which the sync word are transmitted are different. This arrangement helps detection and synchronization of the signals, despite the unavoidable frequency mismatches and collisions.
Claims12
A radio-transmitting device comprising a radio interface operating in a predetermined frequency band, operatively arranged for modulating a carrier having a frequency in the frequency band, while switching the frequency of the carrier among several hopping frequencies in the frequency band, according to a hopping sequence, to obtain a spread-spectrum modulated signal,
- wherein the spread-spectrum modulated signal includes, in a preamble portion, a plurality of sync words, each combined with at least one instance of a sequential index, the sync words being transmitted at different frequencies, and a data portion following the preamble portion and including a plurality of frequency hops.
A radio-receiving device comprising a radio interface operating in a predetermined frequency band, operatively arranged for demodulating a carrier having a frequency in the frequency band, whereby the frequency of the carrier jumps between several hopping frequencies in the frequency band, according to a hopping sequence, and for obtaining a demodulated signal including, in a preamble portion, a plurality of sync words, each combined with at least one instance of a sequential index, the sync words being transmitted at different frequencies, and a data portion following the preamble portion and including a plurality of frequency hops, and for determining from said sequential index the position of the data portion.
Dependencies are inferred from the claim text.