190results about "Scatter propogation systems" patented technology

The present disclosure is directed to methods and systems for providing a distributed radio communications network. Each of a first gateway and a second gateway may separately receive modulated signals comprising at least a portion of data from a first node of a plurality of geographically-dispersed nodes. The modulated signals may be wirelessly transmitted as radio frequency (RF) signals from the first node, the data gathered or generated by the first node at a first location. A server may receive the modulated signals from the first gateway and the second gateway. As configured by software-defined radio (SDR) software, the server may perform processing of the separately received modulated signals to recover the data. The processing may include demodulation of the modulated signals.

The invention relates to a fall-down detection method and system. The fall-down detection method includes receiving a first WiFi signal flow passing through the environment via a first reception antenna; receiving a second WiFi signal flow passing through the environment via a second reception antenna; determining the physical layer channel state information flow, namely a first CSI flow, of the first WiFi signal flow; determining the physical layer channel state information flow, namely a second CSI flow, of the second WiFi signal flow; determining the phase difference, namely the CSI phase difference, between the physical layer channel state information flow of the first WiFi signal flow and the physical layer channel state information flow of the second WiFi signal flow in the corresponding state at the same time to form a CSI phase difference flow; and determining the fall-down event based on the CSI flows and the CSI phase difference flow.

The present invention provides an apparatus and method for efficient guaranteed transmission variation for the same broadcast signal transmitted from at least two base stations (BS). A radio network controller (RNC) considers a radio channel state of a mobile station (MS), and transmits information to a plurality of BSs located in a cell configured by three sectors for performing mutation. Each BS is equipped with at least two transmit antennas. According to this information, the BS in the cell performs space-time block coding on the data to be transmitted, applies different periodic delays to the data, and transmits the data to the MS through at least two transmit antennas.

A method of wirelessly communicating a screen image between a mobile device and a base station coupled to a display terminal includes establishing a wireless display session between the mobile device and the base station. Electromagnetic (“EM”) radiation emitted from the base station is incident upon an antenna of the mobile device. The screen image is transmitted to the base station for display on the display terminal by modulating a radar cross-section of the mobile device between two or more states to encode the screen image on a backscatter channel of the EM radiation.

A broadband multi-frequency-block Extended Digital Audio Broadcasting X-DAB) transmission method for the interference-free transmission of value-added services at a high data rate to mobile receivers within an analog television channel. At least two simultaneously-broadcast adjacent X-DAB frequency blocks in a single-frequency network are provided. A digital input data stream is multiplexed onto the frequency blocks, with the input data steam being source-coded according to the service content of the input data stream. The input data stream is separated into a plurality of individual dens streams, with the individual data steams each having a respective quality of service importance and being distributed according to the respective quality of service importance among the at least two frequency blocks. The method offers a high degree of flexibility with regard to error protection profiles and thus data rates, and permits the implementation of non-constant-ratio error protection profiles, as well as hierarchical transmission.

The invention relates to a short wave communication reliability evaluation method based on multi-system detection data. The method comprises the steps of: calculating reflection point positions of a short wave communication link and all detection links, and selecting detection link data close to the reflection point position of an ionized layer of the short wave communication link; according to the determined reflection point positions of ionized layers of the detection links and the determined detection link data, forecasting an ionized layer parameter of reflection points of the ionized layers of the detection links; according to the determined reflection point positions of the ionized layers of the short wave communication link and the detection links and the forecasted ionized layer parameter of the reflection points of the ionized layers of the detection links, reconstructing an ionized layer parameter of the reflection point of the ionized layer of the short wave communication link; forecasting the highest available frequency of the short wave communication link by using a short wave propagation forecasting method according to the obtained ionized layer parameter; and calculating the received field intensity when the short wave communication link adopts the highest available frequency for communication according to the obtained highest available frequency, and analyzing the reliability of the short wave communication link.

The invention relates to a communication method between communication devices adopting environment RF wireless charging, and belongs to the technical field of communication adopting the environment RFwireless charging. The technical problem to be solved is to provide the communication method between communication devices adopting environment RF wireless charging. The technical scheme adopted to solve the technical problem is as follows: performing communication by using a transmitter S and a receiver D, wherein the transmitter S is capable of performing an active data transmission mode or a data backscattering transmission mode, and performing RF energy collection; the receiver D can demodulate data from modulated backscattering and active RF transmission; the data transmission mode can be accomplished by the transmitter S by receiving selection signaling; and the communication method provided by the invention is applied to RF wireless charging communication devices.

Systems and methods for communicating information within a business organization network using a one or more communication bands on a HF communication network. A computer device may be used to control communication by selecting a frequency band and/or frequency at which communication may take place to optimize latencies to at or near the physical limitation of HF radio wave communication over long distances.

To adjust a transmit power for device-to-device communication, a user equipment which performs the device-to-device communication using the transmit power detects that the user equipment enters a coverage area of a radio communication unit. The transmit power of the user equipment for the device-to-device communication is decreased in response to detecting that the user equipment enters the coverage area of the radio communication unit.

A satellite communication system includes a hub, a repeater, a scheduling unit, and a remote. The scheduling unit is configured to synchronize a communication of the system based on an elapsed time between (i) an arrival at the remote of a downstream reference frame transmitted by the hub and retransmitted by the repeater, and (ii) an arrival at the remote of an upstream frame transmitted by the remote and retransmitted by the repeater.

A highly-secure wireless communication system has a transmitter for transmitting the same information at predetermined polarized wave angles having different rotation-polarized waves for rotating the polarized waves of a carrier wave, and a receiver for restoring the reception information at the aforementioned predetermined polarization wave angles and for comparing the restoration results of the predetermined polarization wave angles with one another.

The present invention relates to a multi-service transmission method in microwave communication, which comprises a multi-service data sending method and a multi-service data acceptance method. Wherein, the multi-service data sending method comprises the following steps: judging the priority of service type; judging whether the service data reaches the given packaging length, adding the type of service; packaging the service data of relevant type; adding invalid data mark when the service data does not reach the given packaging length; packaging the invalid data and sending the radio frame. The multi-service data acceptance method comprises the following steps: receiving the radio frame, discerning the service type in the radio frame, unpacking the service data according to the identified service type, discerning the invalid data mark in the radio frame and discarding the invalid data.

A method of obtaining an absolute time reference for a high-frequency (HF) sounding signal includes transmitting a reference signal at a first location and transmitting a sounding signal in close proximity to the transmitting of the reference signal at the first location. The method additionally includes receiving the reference signal at a second location and receiving the sounding signal at the second location. The method further includes determining a relative delay at the second location of the sounding signal in relation to the reference signal. The method also includes determining a propagation mode based upon the relative delay. The method additionally includes determining an absolute time reference based upon the propagation mode being observed. Additional methods and associated systems for implementing the methods are also provided.

The invention discloses a communication method and system of a multi-antenna backscatter tag. The method comprises the following steps: S1, an excitation source signal is sent to a multi-antenna tag and a reader; S2, the multi-antenna tag performs space-backscattering joint modulation on the incident excitation source signal and tag information to obtain a tag reflection signal; and S3, the readerreceives a superposed signal of the label reflection signal and the excitation source signal, and recovers the excitation source signal and the label information by performing joint signal detectionon the superposed signal. Space-back scattering joint modulation is carried out on an incident excitation source signal and label information in a multi-antenna label; and, in each time slot, one tagantenna in the multi-antenna tag is selected to work according to the tag antenna index in the tag information, space coupling between the tag antennas in the multi-antenna tag is avoided, the distance between the antennas can be smaller than the half wavelength of a source signal, the size of the multi-antenna tag is reduced, and meanwhile the communication performance is greatly improved.

Proposed are a multi-access method and apparatus for a LoRa tag using backscatter communication. The multi-access apparatus for a LoRa tag using backscatter communication may include a contention slot unit configured to receive a signal for a contention participation request from a base station and participate in a contention according to a distributed queuing (DQ) protocol using a backscatter signal if data to be transmitted is present, an FBP unit configured to receive a result of the contention from the base station and check whether the result of the contention is a success, and a data slot unit configured to transmit sensed data to the base station using the backscatter signal if the result of the contention is a success.

The invention discloses a synchronization self-adaptation short-wave communication frequency-selecting method based on ionized layer data. The synchronization self-adaptation short-wave communication frequency-selecting method based on the ionized layer data comprises the step one that the maximum usable frequency of a channel is obtained by utilizing the ionized layer data according to short-wave communication link timing, wherein the ionized layer data comprise real-time observational data, historical data and the like; the step two that the range of usable frequency is determined according to the maximum usable frequency and by combining communication efficiency and/or duration of passable frequency; the step three that the range of the usable frequency is sent to a synchronization self-adaptation short-wave communication system; the step four that the synchronization self-adaptation short-wave communication system obtains the optimum usable frequency by scanning the range of usable frequency in a synchronization self-adaptation frequency-selecting mode, and then communication can be carried out. The synchronization self-adaptation short-wave communication frequency-selecting method based on the ionized layer data can overcome the defect in the prior art that the efficiency is low or it is difficult to obtain the optimum usable frequency due to the fact that channel information needs to be set in advance, and can efficiently select the optimum communication frequency. Thus, the synchronization self-adaptation short-wave communication frequency-selecting method based on the ionized layer data has an obvious effect on improvement of comprehension effectiveness of short-wave data communication.

A backscatter tag device includes, in part, a receiver configured to receive a packet conforming to a communication protocol defining a multitude of codewords, a codeword translator configured to translate at least a first subset of the multitude of codewords disposed in the packet to a second multitude of codewords defined by the protocol in response to a data the backscatter tag is invoked to transmit, and a transmitter configured to transmit the packet supplied by the codeword translator at a frequency different than the first frequency at which the packer is received. The communication protocol may optionally be the 802.11 g/n, ZigBee or the Bluetooth communication protocol.

The invention discloses a wireless communication method and system based on a backscattering antenna array. The method comprises attaching backscattering circuit label which is low in consumption, small in size and low in price to the periphery of the AP to construct the multipath propagation characteristic of the wireless signal, extracting representative characteristics of the backscattered signal obtained by reflecting the sending signal through the backscattered circuit label; comparing the similarity among the representative features by adopting a distance search algorithm; contructing propogation feature vector, and finally, classifying the identities of the attackers and the legal wireless equipment based on the similarity of the propagation feature vectors by using a machine learning algorithm without using an expensive antenna array or performing any hardware modification on the existing equipment, so that the hardware cost is low, the operability is high, and the accuracy andthe efficiency of identifying the active attackers by the system are greatly improved.

A possibility for transmitting data via a radiolink with a timeslot structure in a radiocommunications system is described, measurement data for determining the transmission characteristics of the radiolink being inserted within the timeslot structure in dependence on the variation with time of the transmission characteristics of the radiolink between the base station and the terminal at the subscriber end in the timeslot structure.

The invention discloses a high-order multi-dimensional spread spectrum modulator, a high-order multi-dimensional dispreading demodulator and a scatter communication high-order multi-dimensional spread spectrum device based on the high-order multi-dimensional spread spectrum modulator and the high-order multi-dimensional dispreading demodulator, and relates to a modulation-demodulation device with limited transmitting power, strong anti-interference capability and extremely low detection threshold in the scatter communication field. A high-order multi-dimensional spread spectrum algorithm is adopted, time diversity is combined, the anti-interference capability and anti-frequency offset capability of a scatter communication system are effectively improved under the condition of limited transmitting power, channel fading can be smoothed, and the diversity gain is obtained. In the invention, high-performance channel coding and decoding are used at the same time, the bit error rate performance of a system is improved, and especially reliable information transmission can be achieved under the conditions that the transmission loss is high, the systematic normalized frequency offset is large and the detection threshold is extremely low during long-distance scatter communication.

The embodiment of the invention provides an array antenna, a beam forming method and a sensing and communication integrated system, and the array antenna based on the integration of sensing and communication comprises a sensing sub-array and a communication sub-array. The sensing sub-arrays are used for generating three-dimensional sensing wave beams so as to realize a sensing function in the sensing and communication integrated system; and the communication sub-array is used for generating two-dimensional communication beams so as to realize a communication function in the perception and communication integrated system. Therefore, the application range sensed by the unmanned aerial vehicle can be expanded.

The invention discloses an ionized layer foF2 parameter reconstruction method based on a single receiving station. The method comprises the steps of S1, selecting a plurality of short wave amplitude modulation broadcasting station signals with different signal frequencies as transmitting stations, and acquiring transmitting frequencies and coordinate positions of the transmitting stations; S2, computing great circle distances on the ground between the transmitting stations and the receiving station according to the coordinate position; S3, after the signal frequencies and great circle distances on the ground are known, acquiring an ionized layer parameter through inversion by using a genetic algorithm according to pitch angle data of the receiving signal acquired by measurement; and S4, performing a Kriging interpolation algorithm on the foF2 parameter in the ionized layer parameter to acquire a large area foF2 reconstruction result. According to the method provided by the invention, the ionized layer model foF2 parameter can be acquired via the genetic algorithm on the basis of not building the transmitting stations, and the large area foF2 reconstruction result is acquired via the Kriging interpolation algorithm, so that the method is provided for solving the problem that the ionized layer foF2 parameter cannot be acquired in real time due to the fact that most areas do not have ionosonde stations, and the positioning accuracy of the radar system can be effectively improved.