Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for processing communications signals using a machine-learning network are disclosed. In some implementations, pilot and data information are generated for a data signal. The data signal is generated using a modulator for orthogonal frequency-division multiplexing (OFDM) systems. The data signal is transmitted through a communications channel to obtain modified pilot and data information. The modified pilot and data information are processed using a machine-learning network. A prediction corresponding to the data signal transmitted through the communications channel is obtained from the machine-learning network. The prediction is compared to a set of ground truths and updates, based on a corresponding error term, are applied to the machine-learning network.

An optical transmission system including an optical transmitter and an optical receiver, wherein the optical transmitter includes a signal coding unit that performs non-linear block coding on an M (M is an integer greater than or equal to 1)-value symbol sequence or a bit sequence input as data information to generate an L (L is an integer greater than or equal to 2, L>M)-value symbol sequence that corresponds to the M-value symbol sequence or the bit sequence in one-to-one correspondence, a digital-to-analog conversion unit that converts the generated L-value symbol sequence to an analog signal, and a modulator that generates an optical modulation signal by performing modulation based on the analog signal, and the optical receiver includes a light receiving unit that receives the optical modulation signal transmitted from the optical transmitter and converts the optical modulation signal to an electrical signal, and a signal decoding unit that restores the M-value symbol sequence or the bit sequence by performing processing that is the reverse of processing performed by the signal coding unit, on the electrical signal.

A user equipment that includes a radio transceiver that performs wireless communication in an unlicensed band, and circuitry that performs RLM using downlink physical signals, measures a radio link quality, evaluates the radio link quality against thresholds Qout and Qin, indicates out-of-sync to higher layers from a physical layer, indicates in-sync to the higher layers from the physical layer, starts a first timer when the out-of-sync is consecutively indicated to the higher layers from the physical layer, and determines that a radio link failure occurs in a case where the first timer expires without consecutive in-sync indications, and the first timer is different from a second timer used to determine whether a radio link failure occurs in a wireless communication in one or more serving cells in a licensed band.

Systems, devices, and methods of the present invention facilitate secure communication by altering the set of symbol waveforms that may be in use in particular symbol times defined herein as Symbol Waveform Hopping. SWH may be enabled by selecting two or more modulation formats that have sufficiently comparable communication performance (e.g., occupied bandwidth and signal power efficiency), but characterized by symbol waveform alphabet that include different symbol waveform, so that the overall transmission/communication performance of data stream in a signal transmission channel of the system is not significantly affected by switching between modulation formats. Some or all of the symbol waveforms in each alphabet may not be present in other alphabets.

A vehicle-based device for a vehicle, in particular a rail vehicle, includes a receiving device which, when passing a track-based transmission device, is configured for receiving a signal, which is at least also frequency-modulated, from the track-based transmission device. The vehicle-based device includes an evaluation device which is configured for generating a crosstalk warning, namely in accordance with signal levels at different frequencies of the received frequency-modulated transmission signal and/or in accordance with the frequency curve. A vehicle, in particular a rail vehicle, and a method for transmitting at least one piece of information from a track-based transmission device to a passing vehicle, in particular a rail vehicle, are also provided.

A method for selection by an ambient backscatter system including a source as well as transmitting and receiving devices, the source being associated with a precoder for focusing signals towards the devices. Furthermore, the method includes, for a plurality of values ϕ_1, . . . , ϕ_N: a phase-shift, by the source, of one of the components of the precoder according to the value ϕ_i, so as to obtain a precoder Q_i; an emission, by the source, using the precoder Q_i; an acquisition, by the receiving device, of power measurements during non-backscattering and backscattering states, a determination, by the receiving device, of a value D1_i representative of a power deviation between the measurements. The method also includes a selection, by the receiving device, of a maximum value among the values D1_1, . . . , D1_N.

Systems, methods, and apparatus are provided for automated identification of baseline data and changes in state in a wireless communications spectrum, by identifying sources of signal emission in the spectrum by automatically detecting signals, analyzing signals, comparing signal data to historical and reference data, creating corresponding signal profiles, and determining information about the baseline data and changes in state based upon the measured and analyzed data in near real time, which is stored on each apparatus or device and/or on a remote server computer that aggregates data from each apparatus or device.

Systems, methods, and apparatus are provided for automated identification of baseline data and changes in state in a wireless communications spectrum, by identifying sources of signal emission in the spectrum by automatically detecting signals, analyzing signals, comparing signal data to historical and reference data, creating corresponding signal profiles, and determining information about the baseline data and changes in state based upon the measured and analyzed data in near real time, which is stored on each apparatus or device and/or on a remote server computer that aggregates data from each apparatus or device.

A method of reducing transmission power for an encoded data stream includes the steps of receiving an incoming data stream having equal probability for a plurality of incoming data bits, assigning a symbol scheme to the received data bits of the incoming data stream according to probabilities of occurrence of individual ones of the received data bits, and transmitting an outgoing data stream according to the assigned symbol scheme having a second average transmit power, different than the first average transmit power, for a plurality of outgoing symbols.

An audio system includes a base station, an interface that enables transmission of audio content from a handheld media device to the base station via a cable, and one or more remote speakers configured to receive the audio content from the base station. The base station includes a housing, a speaker integrated within the housing to produce an audible signal from the audio content provided by the handheld media device, and a transceiver integrated within the housing for wirelessly transmitting the audio content to the one or more remote speakers. The one or more remote speakers are configured to wirelessly relay the audio content, thereby to supply the audio content beyond the transmission range of the transceiver.