233results about How to "Accurate demodulation" patented technology

Embedded piezoelectric sensors in large civil structures for structural health monitoring applications require data communication capabilities to effectively transmit information regarding the structure's integrity between sensor nodes and to the central processing unit. Conventional communication modalities include electromagnetic waves or acoustical waves. While guided elastic waves can propagate over long distances on solid structures, their multi-modal and dispersive characteristics make it difficult to interpret the channel responses and to transfer useful information along pipes. Time reversal is an adaptive transmission method that can improve the spatiotemporal wave focusing. The present disclosure presents the basic principles of a time reversal based pulse position modulation (TR-PPM) method and demonstrates TR-PPM data communication by simulation. The present disclosure also experimentally demonstrates data communication with TR-PPM on pipes. Simulated and experimental results demonstrate that TR-PPM for data communications can be achieved successfully using guided elastic waves.

The present invention relates to a method of a Relay Node (RN) using a reference signal. The method includes receiving information about a Dedicated Reference Signal (DRS) which is used to demodulate a control channel via high-layer signaling from an evolved-NodeB (eNB), receiving control information through the control channel from the eNB, receiving data through a data channel from the eNB, and demodulating the control information and the data. The control information is demodulated using a DRS indicated by the information about the DRS, and the data are demodulated using a DRS indicated by the control information.

A radio base station includes: a category acquisition unit configured to acquire one or more mobile station categories indicating capability of a mobile station with which to communicate; a category determination unit configured to determine a mobile station category to be applied to radio communications with the mobile station from the mobile station categories acquired by the category acquisition unit to correspond to one of parameters to be used in rate matching processing of the mobile station; and a category notification unit configured to notify the mobile station of the mobile station category determined by the category determination unit.

The invention relates to a method with strong anti-multi-path capability for processing moveable underwater sound communication signals, including two parts, namely a transmitter processing method and a receiver processing method, wherein the transmitter processing method includes the operations of error correction of coding, data packing, digital interpolation, base band shaping wave filtering, upper modified frequency modulation, and the like; and the receiver processing method includes the operations of digital wave filtering, frame synchronous judgment, preliminary compensation of Dopplerfrequency shift, lower modified frequency modulation, bit synchronous judgment, fine compensation of Doppler frequency shift, digital equalization, error correction of decoding, etc. The invention carries out the intercrossing treatment on technologies of synchronous judgment, compensation of Doppler frequency shift, compensation of multi-path effect, and the like, and guarantees that under the environment of strong Doppler frequency shift, the system can realize the accurate synchronism of signals and carries out real-time estimation and compensation on the effect of strong Doppler frequencyshift; and the adopted blind equalization method can carry out effective tracking compensation on the time varying multi-path effect of an underwater sound signal channel, thereby greatly increasing the integral stability and the bit error rate performance of an underwater sound communication system and enduing the system with the capability of reliable communication during movement.

A reception circuit can receive a plurality of standard time signals and has a reception means for selectively receiving and demodulating any one of the plural standard time signals, and a control means for outputting a control signal that controls the reception means. The reception means includes a signal amplifier unit for amplifying a reception signal representing the received standard time signal; a signal extraction unit for extracting a signal of a specific frequency from the amplified reception signal; a rectifier unit for rectifying the extracted signal of the specific frequency; and a demodulation unit for demodulating the rectified signal of the specific frequency. The signal extraction unit includes a plurality of crystal filters corresponding to the frequencies of the plural standard time signals; a plurality of parallel capacitances corresponding to the plural crystal filters and parallel connected to the plural crystal filters; a filter switching unit for switching the plural crystal filters based on the control signal; and a parallel capacitance switching unit for switching the plural parallel capacitances based on the control signal. The control means outputs to the filter switching unit and the parallel capacitance switching unit a control signal denoting the switch states enabling the reception means to receive the standard time signal.

A system that combines MIMO spatial multiplexing and dual polarization transmission is provided. The system is constructed with a simple circuit configuration, whereby a wireless communication system which accurately demodulates signals that are multiplexed doubly, both spatially and in polarization, is provided. The wireless communication system is a MIMO communication system that uses a plurality of antennas to form a plurality of fixed transmission channels, and includes a transmitting section and a receiving section. The transmitting section performs MIMO spatial multiplexing as well as dual polarization transmission of transmitting two independent signals in the same band by using two mutually orthogonal polarizations of radio waves as signals to be transmitted from respective antennas on a transmitting side. The receiving section includes an inference canceller and a MIMO signal processing circuit that is connected to the interference canceller. The interference canceller performs signal processing for eliminating an interference component between the polarizations by adaptive control on signals received by respective antennas on a receiving side. The MIMO signal processing circuit performs signal processing for MIMO spatial demultiplexing independent of the signal processing of the interference canceller.

The invention discloses a method and a device for transmitting a demodulation reference signal, as well as a method and a device for receiving a demodulation reference signal. The transmitting method comprises the following steps: determining a PRB (program require block) which is subjected to subcarrier migration with the PRB of a second base station among the PRB included in a sub frame to be sent of a first base station when the first base station and the second base station execute cooperative transmission; performing frequency shift on RE (receiving equipment) carried with a DM-RS (demodulation reference signal) in the direction from the DC (direct current) subcarrier of the second base station to the DC subcarrier of the first station, in the time frequency resource consisting of the determined PRB (program require block), according to the amount of the migration subcarrier of the determined PRB; in the PRB included in the sub frame, mapping the DM-RS to the RE for carrying the DM-RS; and then sending the sub frame to a user terminal. By utilizing the technical scheme, the problems in the prior art that interferences of a data symbol and a pilot symbol are likely to occur on the PRB subjected to subcarrier migration, when two base stations execute cooperative transmission, and the error code rate is very high when the user terminal demodulates the DM-RS are solved.

Resource allocation information is signalled to user devices (UE1, UE2, UE3, UE4) in a mobile telecommunications communications system in which each user device is allocated plural resource allocations (RB) in a TTI (50) by, for each user device, providing information (I1) regarding a selected resource allocation allocated to that user device in a control channel (L1, L2, L3, L4) and providing information (I2, I3) regarding at least one other resource allocation allocated to that user device in a data channel (52) in the selected resource allocation. In one example, the selected resource allocation is the first resource allocation (RB1) allocated to that user device (UE1) and information regarding each successive further resource allocation is provided in a data channel in the resource allocation preceding that successive further resource allocation. In another example, the selected resource allocation is the first resource allocation allocated to that user device and information regarding each successive further resource allocation is provided in a data channel in the first resource allocation. In another example, the selected resource allocation is the resource allocation that is indicated to have the best channel quality. The resource allocation information may be provided in the data channel of the one resource allocation as a list of RFI fields or as a bit map.

The present invention is to provide a noncontact tag, comprising: a clock extraction unit for extracting a clock from a received carrier wave; a demodulation unit for outputting a demodulated signal comprising a logic signal whose logic state changes responding to each of a non-modulation period and modulation period of the carrier wave; a division unit for generating a division clock from the clock input from the clock extraction unit and also restraining the division clock from being output according to a logic state of the demodulated signal; and a decoding unit for decoding information included in the carrier wave by using a value of counter driven by the division clock.

A wireless communication device includes a Generalized RAKE (G-RAKE) receiver circuit that is configured to determine a traffic-to-pilot gain scaling parameter as part of the impairment correlation determination process that underlies (G-RAKE) combining weight generation. In this manner, the receiver circuit conveniently and accurately accounts for gain differences between the pilot channel of a received CDMA signal, as used for channel estimation, and the traffic channel(s) of the CDMA signal, which carry received data to be recovered. The gain difference accounting enables proper demodulation of amplitude-modulated traffic signals. By way of non-limiting example, such gain scaling may be used for demodulating / decoding High Speed Downlink Packet Access (HSDPA) signals used in Wideband Code Division Multiple Access (W-CDMA) systems.

A downlink control channel time-domain position determination method and device are disclosed. The method includes: a terminal determining a way for acquiring a time-domain position of a downlink control channel and / or a time-domain starting position of a downlink data channel corresponding to the downlink control channel according to a number of repetitions of resources corresponding to the downlink control channel and / or a downlink channel type; the terminal obtaining the time-domain position of the downlink control channel and / or the time-domain starting position of the downlink data channel in accordance with the way.

With the objective of making it possible to accurately estimate a transmission line and accurately demodulate a signal by a receiving device, the present invention provides a transmission system suitable for use between a transmitting device that performs transmission using first and second transmitting antennas, and a receiving device that performs reception using a plurality of receiving antennas, wherein a pilot signal transmitted through the first transmitting antenna is made orthogonal to a pilot signal transmitted through the second transmitting antenna.

An RF tag system is provided, in which in addition to a method of easily sending back MPSK modulated sub-carrier signals on the RF tag side, communication protocols and circuit systems for accurately demodulating modulated waves on the RF tag reader side can be implemented, data transmission from an RF tag to an RF tag reader can be realized over a long operating distance at high speed, and an RF tag can be operated for a long lifetime.

The invention, which belongs to the technical field of the unmanned aerial vehicle detection apparatus, discloses a detection device for an unmanned aerial vehicle-mounted electronic system. The detection device comprises an unmanned aerial vehicle avionics system detection simulation device, a coding and decoding system, and a detection system radio frequency link; the unmanned aerial vehicle avionics system detection simulation device is connected with the coding and decoding system by a serial port; and the coding and decoding system is connected with unmanned aerial vehicle-mounted radio equipment by the detection system radio frequency link. According to the detection device, the miniaturized and portable design scheme is used; the detection workload is small; a few responders are needed; and the detection speed is fast. On the basis of the mode of wired connection of the detection system radio frequency link with the unmanned aerial vehicle-mounted radio equipment, problems that frequent starting up by the ground control station is needed and the collision with self examination of the ground control station exists during the detection process of the unmanned aerial vehicle-mounted electronic system can be solved.

The invention relates to the field of wireless communications, and particularly relates to a reference signal transmitting method, a phase noise determining method and related devices, aiming to solvethe problem that different phase noises of different antenna units or antenna ports at a transmitting end cannot be accurately estimated and compensated in the prior art. The method includes the following steps that: the transmitting end respectively transmits each precoded DMRS and PTRS to a receiving end through the own corresponding antenna groups with the same phase noise, wherein the antennaunits or the antenna ports of the same antenna group have the same phase noise; and when receiving the PTRS, the receiving end performs channel estimation based on each received PTRS to determine thephase change caused by the phase noises corresponding to different antenna groups. Thereby, even if the phase noises of different antennae at the transmitting end are different, the phase changes caused by different phase noises can be accurately determined, and thus all data transmitted by the different antenna groups can be accurately demodulated according to different phase changes.

A RAKE receiving unit (50) despreads and RAKE-combines a receive signal by a spreading code codel of a desired signal. A correlation calculation unit (61) in a canceling-signal generator (60) calculates a correlation value F between the spreading code codel and a non-orthogonal code code2. An amplitude-ratio acquisition unit (62) acquires an amplitude ratio A between a pilot signal and an undesired signal contained in the receive signal, a RAKE combiner (63) RAKE-combines multipath channel estimation values, and a canceling-signal output unit (64) multiplies the correlation value F, amplitude ratio A and result B of RAKE-combination of the channel estimation values and generates a canceling signal (undesired signal component) X. A signal eliminating unit 70 subtracts the canceling signal X from the RAKE-combined signal R that is output from the RAKE receiving unit (50), thereby outputting the desired signal.

Before data is transmitted from a plurality of antennas, a plurality of known symbol sequences are transmitted from these antennas. Each known symbol sequence contains a plurality of known symbols having different subcarrier arrangements. Known symbols transmitted from different antennas have different subcarrier arrangements.

In a code division multiple communication system which prevents the dropout of a whole packet and does not require the generation of a carrier from a received signal, under bad communication path, by generating an orthogonal code with chip synchronization from a correlation peak of a synchronization code sequence output from a surface acoustic wave matched filter, a preamble division of a spectrum spread signal is composed of plural synchronization burst. Each synchronization burst is composed of a synchronization packet division having the Barker code of 11 chips and a dummy division. The period of one synchronization burst (Tburst) is set equally to the period of one symbol in a data division (Tsymbol) which is modulated by the orthogonal sequential code of 64 chips. When the correlation peak of at least one from among plural synchronization code sequences is detected, the orthogonal code can be generated in accordance with the start timing of the first symbol in the data division.

The invention discloses a dipulse optical fiber vibration sensing method based on a time delay optical fiber, and belongs to the technical field of optical fiber sensing. According to the method, twobeams of detection light pulses with an overlapped part are formed by adding the time delay optical fiber; and in an interference signal of Rayleigh scattered light of the two beams of the pulses, demodulation of phase change on a sensing optical fiber is realized, so that vibration information is obtained, and distributed multi-point sensing is realized. According to a system, the structures of coherent detection, an interferometer and the like are omitted; phase information is extracted in a direct detection mode; system configuration is greatly simplified; a demodulation mode is simple andfast; the overall cost is reduced; and the signal-to-noise ratio and the sensitivity are improved.

The invention provides an ultrasonic ranging method and ranging device with high anti-interference performance. Frequency modulation is conducted on a sine wave signal generated by a sine-wave generator through a pseudo code, and transmitting ultrasonic wave is generated and transmitted; echo frequency discrimination demodulation is conducted on the ultrasonic wave echo, so that echo identification is achieved, and the detection is more accurate; moreover, the pseudo code has a good self-correlation characteristic and a good cross-correlation characteristic, and when the pseudo code is applied to the spread spectrum communication, good noise interference-resistant performance and good mutual crosstalk-resistant performance are represented, so that the problem of mutual crosstalk of the ultrasonic wave is solved and the result is accurate; furthermore, the FFT technology is adopted, so that the received wave can be accurately modulated through a few sampling data, frequency resolution is guaranteed, data collecting time of the received wave is shortened, real-time work of the ranging device is greatly improved, and an efficient solution for accurate and rapid ranging and positioning is provided for an autonomous mobile robot.

The invention discloses a signal relay method of transparent relay station comprising steps of receiving signal from base station, demodulating signal, recoding and modulating signal using set format of present transparent relay station, transmitting coded and modulated signal by accessing link, transmitting dedicated pilot symbol using dedicated time frequency domain resource block occupied by relay signal. The invention also discloses signal relay device of a transparent relay station comprising receiving and demodulating module, for receiving and demodulating signal of base station; coding and modulating module, for coding and modulating signal the receiving and demodulating module output; transmitting module, for relaying code modulated signal to terminal by link and simultaneously transmitting dedicated pilot symbol utilizing dedicated time frequency domain resource block occupied by relay signal. In the invention, signal relayed by transparent relay can be correctly demodulated and received.

An optical measurement system includes a rotating element ellipsometer comprising a radiant source and a rotating optical element coupled to the radian source, an optical system to provide a modulated pump beam, a detection system optically coupled to the ellipsometer and a signal analyzer. The rotating element ellipsometer is configured to deliver a probe beam to a measurement spot on a sample and to measure one or more ellipsometric parameters of the sample at one or more discrete wavelengths or wavelength ranges, or a plurality of wavelengths across a wavelength range. Methods for determining sample characteristics from radiation scattered, reflected, diffracted or otherwise emitted from a sample surface using the optical measurement systems are also disclosed.

The invention provides a paging method. A message that paging information contents are changed is sent to a terminal through control information of a group , according to the information, the terminal can monitor the group paging information when the paging information contents are changed, so that when the group paging information are unnecessary to monitor by the terminal, the group paging information can be monitored. The paging method is capable of reducing the power consumption generated by the unnecessary paging of the terminal; meantime, the paging method is beneficial for accurate demodulation of the terminal over a channel.

An embodiment of the invention discloses a WIFI transmitting power regulation method, terminal and system. The WIFI transmitting power regulation method includes the following steps: a WIFI receiving terminal receives a WIFI signal sent by a WIFI transmitting terminal, and detects a signal intensity value of the received WIFI signal; the WIFI receiving terminal determines an indicated transmitting power value of the WIFI transmitting terminal according to the received signal intensity value of the WIFI signal sent by the WIFI transmitting terminal; and the WIFI receiving terminal sends the indicated transmitting power value to the WIFI transmitting terminal, so that the WIFI transmitting terminal adopts the indicated transmitting power value to send the WIFI signal to the WIFI receiving terminal. By adoption of the WIFI transmitting power regulation method provided by the invention, the WIFI receiving terminal can correctly demodulate the received WIFI signal sent by the WIFI transmitting terminal, thereby reducing an error rate.

The present invention discloses a method for reducing the signal peak-to-average ratio in an FBMC system. According to the method, firstly, a signal is pre-processed at a signal transmission end and the data overlapping condition is avoided even after data are multiplied by a phase rotation factor after being subjected to constellation mapping. Secondly, in combination with the conventional PTS method, data are partitioned, and a set of data smallest in peak-to-average ratio among multiple sets of data is selected and transmitted. Therefore, the signal peak-to-average ratio is well reduced. Meanwhile, the signal demodulation is conducted at a receiving end according to the discriminant rule of signals. In this way, the transmission of the sideband information is avoided. According to the technical scheme of the invention, the peak-to-average power ratio of the FBMC system is reduced, while the information demodulation of the receiving end is enabled without the transmission of the phase rotation factor. Under the same condition, the utilization rate of spectrum resources is improved and the use efficiency of the entire system is increased.

This invention is a wireless communication medium processing apparatus which carries out communication with a wireless communication medium, to carry out at least one of reading and writing as to information which was stored in the wireless communication medium, and has a plurality of antenna, a transmission divider which was connected to the plurality of antennas, and a reception compositor which was connected to the plurality of antennas, and is characterized in that the transmission divider divides an inputted signal to output the plurality of antennas, and the reception compositor combines signals from the plurality of antennas and outputs it.

The present application provides a data transmission method and a related device. The method includes that a network device generates a configuration message, wherein the configuration message includes one or more hybrid automatic repeat request (HARQ) process numbers, each of the HARQ process numbers corresponds to one or more license-exempt transmission resources, and the configuration message is used for configuring one or more license-exempt transmission resources for a terminal device in each time-domain period; and the network device transmits the configuration message to the terminal device. The data transmission method solves the problem that a base station, because of incorrectly determining the number of data retransmission times, cannot determine the HARQ process number used bythe terminal device to transmit data so as to cause decoding incapability. The base station can successfully demodulate the data when receiving the license-exempt transmission data. The complexity ofa receiver is reduced.

The invention discloses a low signal-to-noise ratio short frame burst communication open loop demodulation method and a low signal-to-noise ratio short frame burst communication open loop demodulationdevice, and belongs to the technical field of direct sequence spread spectrum demodulation technologies. According to the method, a segmented data processing mode is used for firstly demodulating dispreading data, then performing supply-zero FFT to estimate a frequency offset variation rate and frequency offset and perform compensation. A method of exhaustion is used for accurately estimating andcompensating each frequency offset, the polarity of a frame header is used for performing defuzzification on the phase, to complete correct demodulation of the data. Compared with the prior art, themethod and the device provided by the invention overcome the disadvantages that traditional phase-locked loop coherent demodulation devices are fuzzy in phase and slow in convergence speed, the frequency offset and the frequency offset variation rate can be quickly searched and compensated, the phase discrimination and phase correction can be completed, the short time is ensured, and a direct sequence spreading signal can be normally demodulated under the condition of a low signal-to-noise ratio.

The invention discloses a signal arrival detection method suitable for downlink data link communication of an unmanned plane, which comprises the following steps: firstly, initializing functions of a communication system; secondly, performing signal energy continuous monitoring and calculating correlation energy values by an energy detection unit; thirdly, determining the maximum value and the position of correlation energy by a comparison module; and fourthly, confirming the arrival of signals. The signal arrival detection method shortens the time for locking a synchronizing functional module of a demodulation terminal, and determines the optimal initial sampling point on the basis of the arrival of detection signals, and the position of the optimal sampling point is the position of the maximum value of the energy. The signal arrival detection method can ensure accurate demodulation of the signals and reduce the error rate, and has good stability.

A method of decoding a backhaul downlink signal of a relay station is provided. The method includes: receiving by the relay station a transmission rank value for a backhaul downlink from a base station through a high-layer signal; receiving control information from the base station through a control region; and decoding the control information, wherein the transmission rank value for the backhaul downlink is a transmission rank value assumed when the relay station decodes the control information, and wherein the control information is mapped to a resource element which does not overlap with a dedicated reference signal resource element mapped to the control region by assuming the transmission rank value for the backhaul downlink.