A method of communicating through the earth which includes the steps of using a digital pulse train to generate a sweep pulse train which controls the frequency of a magnetic field at a first location, and at a second location, detecting the magnetic field and producing a signal at a frequency dependent on the frequency of the sweep pulse train, and extracting a replica of the digital pulse train from the signal.

A transmission device includes a modulation unit that performs chirp-spread modulation on an input information series to generate a modulation signal; a delay unit that provides, to a plurality of modulation signals obtained by duplicating the modulation signal generated by the modulation unit, delays having lengths different from each other, a difference between the delays being an integral multiple of a reciprocal of a bandwidth of the modulation signal; and a plurality of transmission antennas that transmit the plurality of modulation signals, respectively, to which the delays are provided by the delay unit.

The present disclosure may be embodied as a transmitter for multiuser multicarrier-chirp-division-multiplexing (“MU-MCDM”) communications. The present disclosure may be embodied as a receive for MU-MCDM communications. The present disclosure may also be embodied as a method for transmitting an MU-MCDM communication signal. The present disclosure may also be embodied as a method for receiving an MU-MCDM communication signal.

A velocity measurement signal transmission and receiving method for an intelligent driving system includes generating a plurality of chirp signals for measuring moving velocities of one or more moving targets (301); and transmitting the plurality of chirp signals in a time-division multiplexing (TDM) repetition cycle by using M antennas (302), where the TDM repetition cycle includes one single-antenna transmit mode sub-cycle and L consecutive multi-antenna transmit mode sub-cycles.

A receiver includes: a correlation value calculation unit calculating a first cross-correlation function between a received signal, having a preamble spread with an up chirp and a down chirp, and the up chirp and calculating a second cross-correlation function between the received signal and the down chirp; a power value calculation unit calculating first and second power values of the first and second cross-correlation functions; a correlation power memory storing the first and second power values at each sample timing for one period of a spread code; a threshold determination unit determining first and second estimated timings from the first and second power values for one period of the spread code, respectively; and an estimation unit estimating a spread code timing of a transmitter using the first and second estimated timings, and performing coarse estimation of a frequency offset with respect to the transmitter.

A method is provided. In some examples, the method includes generating, by processing circuitry, a spread of chips representing an input bit. In addition, the method includes converting, by the processing circuitry, the spread of chips to a plurality of symbols comprising a pair of symbols. The method also includes mapping, by the processing circuitry, the pair of symbols to a single carrier signal and generating, by the processing circuitry, a radio-frequency (RF) signal based on the single carrier signal. The method further includes transmitting, by the processing circuitry via an antenna, the RF signal.

Systems and methods for digitally synthesizing chirp signal in a low intermediate frequency (IF) band and using frequency multipliers to generate a higher frequency signal for radar applications are described. An embodiment includes a chirp signal generator that includes: a direct digital frequency synthesizer (DDFS) that is configured to receive an input sync signal and a frequency reference signal and generate several chirp signals at a first frequency that is in a low intermediate frequency (IF) band, several frequency multipliers that are configured to increase the chirp signals to higher frequencies and several bandpass filter circuits that are configured to remove nonlinearities from the chirp signals to generate a clean output signal.

Some embodiments of the present disclosure provide a transmit point that transmits a downlink chirp sensing waveform (DL CSW) signal. A device receives the DL CSW signal and obtains a cloned chirp sensing waveform. The cloned chirp sensing waveform includes a parameter that can be uniquely associated with the device. The device transmits a UL cloned CSW signal based on the cloned chirp sensing waveform. The transmit point receives the UL cloned CSW signal and processes the UL cloned CSW signal to estimate a pose for the device and associate the estimated pose with the identity of the device.

Ultra-Wideband (UWB) technology is a wireless technology for the transmission of large amounts of digital data as modulated coded impulses over a very wide frequency spectrum with very low power over a short distance. However, to support their deployment in a wide range of applications it would be beneficial to provide solutions which: exploit multiple directive antennas oriented in different directions to ensure spatial filtering of undesired signals and increase signal strength; exploit dynamic configuration of the multi-pulse bundles employed to transmit the bits/symbols within the packets to enhance link quality of service; exploit dynamic configuration of the band or bands which the transmitter operates upon; and exploit antenna sub-systems providing omnidirectional radiation patterns with implementations offering filtering and balun functions with small footprint and low cost.

An information processing device and method, a transmitting device and method, and a receiving device and method are disclosed for multiplexing transmission signals in the same channel. In one example, transmission signals are generated by performing chirp modulation on data to be transmitted, and the transmission signals are multiplexed by shifting transmission timings of a plurality of transmission signals in a time direction and transmitting the transmission signals. Further, a plurality of chirp-modulated transmission signals which are multiplexed by shifting the transmission timing in the time direction and transmitted from a transmission side are received, and the plurality of received transmission signals are dechirped at timings according to the transmission timings.