A method for synchronizing a signal having modulated chirps. The modulation corresponds to circular permutation of the pattern of variation in the instantaneous frequency of a chirp over the symbol time. For a portion of the signal that is representative of at least one chirp, estimating a first piece of time synchronization information representative of a time shift in the signal relative to a given time reference. Using the first piece of time synchronization information, a piece of fractional frequency synchronization information is estimated, that is representative of a frequency shift in the signal relative to a given frequency reference modulo the inverse of the symbol time. Using the piece of fractional frequency synchronization information, second time synchronization information is estimated, representative of a time shift in the signal relative to the given time reference.

Apparatuses, systems, and methods for transmitting and multiplexing chirp signals for communications are provided. An example apparatus includes an antenna, a radio, and processing circuitry. The radio may be configured to transmit and receive wireless communications via the antenna, and the processing circuitry configured to establish a wireless communications link with a receiving communications device. The signaling transmitted by the antenna via the radio as controlled by the processing circuitry may include a plurality of sequenced chirp signals within an orthogonal frequency division multiplexing (OFDM) framework.

A sensor controller includes a transmitter configured to transmit an uplink signal including a first partial signal and a second partial signal. The transmitter is configured to transmit the first partial signal by direct spreading using a first spread code and transmit the second partial signal by direct spreading using a second spread code which is different from the first spread code and which has an identical chip time length to the first spread code. An active stylus includes a receiver configured to receive an uplink signal including a first partial signal and a second partial signal. The receiver is configured to synchronize with the uplink signal by detecting the first partial signal using a first spread code and thereafter detect the second partial signal using a second spread code, which is different from the first spread code and has an identical chip time length to the first spread code.

A method for encoding signals using frequency sweeps in a downhole environment, in some embodiments, comprises: obtaining a digital signal; encoding the digital signal using one or more frequency sweeps to produce an encoded signal; transmitting the encoded signal from a transmitter to a receiver, at least one of the transmitter or receiver disposed downhole; receiving the encoded signal at the receiver; and decoding the encoded signal at the receiver to produce a decoded digital signal.

A method for estimating information symbols conveyed by a signal including modulated chirps. The modulation corresponds to circular permutation of the pattern of variation in the instantaneous frequency of a basic chirp over the symbol time. A first demodulation of a portion of the signal that is representative of at least two chirps delivering: an estimation of a first modulation symbol associated with a first chirp with a stronger amplitude among the two chirps, an estimation of the amplitude and phase of the first chirp, a generation of a signal that is representative of the first chirp from the estimation, and a coherent subtraction of the signal that is representative of the first chirp from the portion of the signal delivering an updated portion of the signal. A second demodulation of the updated portion delivering an estimation of a second modulation symbol associated with a second chirp.

A wireless networking system is provided. The wireless networking system includes a base station device including processing circuitry configured to detect a transmission rate from a portion of a preamble of an incoming packet transmission signal and adapt a radio configuration to receive a remainder of the incoming packet transmission signal at the transmission rate.

A wireless communication system, comprising one or several nodes (A) equipped by a wireless radio interface that is adapted for transmitting digital messages modulated in the form of a series of frequency chirps, for example, LoRa-modulated radio signals. The message is received simultaneously by several base stations (C, D, E), and a server (S) is arranged for dividing the frames by the diverse stations and recombining a corrected frame for the intended recipient (B) based on error codes. Advantageously, the base stations being adapt their timing error compensation strategy when the error codes indicate a corruption of the message.

Aspects described herein include receiving, at a base station operating in a wireless communication network, at least one chirp signal including at least one system information block request bitmap that identifies one or more of a plurality of system information blocks corresponding to each of one or more system information requests, identifying the one or more system information requests, generating a message in response to the one or more system information requests, encoding at least the portion of the message based at least in part the at least one system information block request bitmap to define an encoded message; and transmitting, over a broadcast channel, the encoded message in response to the chirp signal. A user equipment may include aspects for transmitting the chirp signal and receiving the encoded message.

A wireless communication method in a network comprising one or several beacons and a plurality of end-points, comprising: sending by a beacon a timing message modulated according to a chirp spread spectrum format, receiving said timing message in one or several end-nodes a receiver, detecting said timing message aligning a local frequency reference and/or time reference of the end-node to the time reference of the transmitter by means of said timing message.

A gateway device having a baseband processor for processing a plurality signals carrying a digital information modulated in the form of chirp signal, the chirp signals being either base chirps, for which the frequency changes from an initial instant to a final instant according to a predetermined base chirp function or modulated chirps, whose instantaneous frequencies vary according to one of a plurality of a functions that differ from said base chirp function, characterized in that the gateway device is arranged for simultaneously demodulating a plurality of signals having received at a same frequency and exhibiting different bitrates.