A method and apparatus detects and estimates geo-observables of navigation signals employing civil formats with repeating baseband signal components, i.e., “pilot signals,” including true GNSS signals generated by satellite vehicles (SV's) or ground beacons (pseudolites), and malicious GNSS signals, e.g., spoofers and repeaters. Multi-subband symbol-rate synchronous channelization can exploit the full substantive bandwidth of the GNSS signals with managed complexity in each subband. Spatial/polarization receivers can be provided to remove interference and geolocate non-GNSS jamming sources, as well as targeted GNSS spoofers that emulate GNSS signals. This can provide time-to-first-fix (TTFF) over much smaller time intervals than existing GNSS methods; can operate in the presence of signals with much wider disparity in received power than existing techniques; and can operate in the presence of arbitrary multipath.

Various embodiments provide for data transmission using modulated carrier signals to carry data, where the carrier signal comprises a predetermined sequence of symbols. An embodiment can be used in such applications as data network communications between sensors (e.g., cameras, motion, radar, etc.) and computing equipment within vehicles (e.g., smart and autonomous cars).

The present invention discloses a method for processing a preamble sequence and header for a data packet, comprising the following steps of: using a bit sequence of a fixed pattern to replace a scrambled pseudo-random bit sequence in a SYNC field in the preamble sequence, and spreading the SYNC field by a Barker code; extending a length of a spreading code and spreading an SFD field in the preamble sequence by the extended spreading code; and extending a length of a spreading code and spreading a header field by the extended spreading code. The present invention may significantly improve the performance of reception and detection for the preamble sequence (the SYNC field and the SFD field) and the PLCP header field, better overcome long-distance channel conditions, enhance the signal stability of transmission; and meanwhile the present invention is easy to implement and only requires little modifications to the circuit of a conventional Wi-Fi device.

The present invention discloses a method for processing a preamble sequence and header for a data packet, comprising the following steps of: using a bit sequence of a fixed pattern to replace a scrambled pseudo-random bit sequence in a SYNC field in the preamble sequence, and spreading the SYNC field by a Barker code; extending a length of a spreading code and spreading an SFD field in the preamble sequence by the extended spreading code; and extending a length of a spreading code and spreading a header field by the extended spreading code. The present invention may significantly improve the performance of reception and detection for the preamble sequence (the SYNC field and the SFD field) and the PLCP header field, better overcome long-distance channel conditions, enhance the signal stability of transmission; and meanwhile the present invention is easy to implement and only requires little modifications to the circuit of a conventional Wi-Fi device.

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.

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.

Provided are a pulse-matched filter-based packet detection apparatus and method. The packet detection apparatus includes a photoelectric converter for converting an optical wireless communication signal into an electrical signal, an analog-to-digital converter (ADC) for converting the electrical signal into a digital signal, a pulse-matched filter for outputting a first correlation representing a correlation between a pulse obtained by oversampling a modulated pulse and the digital signal, a correlator for outputting a second correlation representing a correlation between the first correlation and a preamble code, a packet detection signal generator for generating a packet detection signal by comparing the second correlation and a packet detection threshold value, and a demodulator for demodulating the digital signal based on the packet detection signal.

Provided are a pulse-matched filter-based packet detection apparatus and method. The packet detection apparatus includes a photoelectric converter for converting an optical wireless communication signal into an electrical signal, an analog-to-digital converter (ADC) for converting the electrical signal into a digital signal, a pulse-matched filter for outputting a first correlation representing a correlation between a pulse obtained by oversampling a modulated pulse and the digital signal, a correlator for outputting a second correlation representing a correlation between the first correlation and a preamble code, a packet detection signal generator for generating a packet detection signal by comparing the second correlation and a packet detection threshold value, and a demodulator for demodulating the digital signal based on the packet detection signal.

A wireless device is configured to produce a signal in a time slot, the signal having a first portion and a second portion. Wherein, the first portion being a first in time in the time slot and the second portion being last in time in the time slot. Further, the first portion having data and a multiplexed first pilot and the second portion having a pilot sequence and a cyclic prefix. The wireless device transmits the produced signal in the time slot.

A wireless device is configured to produce a signal in a time slot, the signal having a first portion and a second portion. Wherein, the first portion being a first in time in the time slot and the second portion being last in time in the time slot. Further, the first portion having data and a multiplexed first pilot and the second portion having a pilot sequence and a cyclic prefix. The wireless device transmits the produced signal in the time slot.