619 results about "Frequency-shift keying" patented technology

A communications bridge device communicates between a consumer electronics device, such as a smart telephone, and an implantable medical device. The bridge forwards instructions and data between the consumer electronics device and the implantable medical device. The bridge contains a first transceiver that operates according to a communication protocol operating in the consumer electronics device (such as Bluetooth®), and second transceiver that operates according to a communications technique operating in the implantable medical device (e.g., Frequency Shift Keying). A software application is installed on the consumer electronics device, which provides a user interface for controlling and reading the implantable medical device. The software application is downloadable using standard cellular means. The bridge is preferably small, and easily and discreetly carried by the implantable medical device patient. The bridge is preferably also simple to operate, and may have only a simple user interface, or no user interface at all.

A base station having the strongest downlink signal is identified by utilizing a unique slope of a pilot tone hopping sequence being transmitted by a base station. Specifically, base station identification is realized by determining the slope of the strongest received pilot signal, i.e., the received pilot signal having the maximum energy. In an embodiment of the invention, the pilot tone hopping sequence is based on a Latin Squares sequence. With a Latin Squares based pilot tone hopping sequence, all a mobile user unit needs is to locate the frequency of the pilot tones at one time because the pilot tone locations at subsequent times can be determined from the slope of the Latin Squares pilot tone hopping sequence. The slope and initial frequency shift of the pilot tone hopping sequence with the strongest received power is determined by employing a unique maximum energy detector. In one embodiment, the slope and initial frequency shift of the pilot signal having the strongest received power is determined by finding the slope and initial frequency shift of a predicted set of pilot tone locations having the maximum received energy. In another embodiment, the frequency shift of the pilot signal with the strongest, i.e., maximum, received power is estimated at each of times “t”. These frequency shifts are employed in accordance with a prescribed relationship to determine the unknown slope and the initial frequency shift of the pilot signal.

Strong authentication tokens for generating dynamic security values having an acoustical input interface for acoustically receiving input data are disclosed. The tokens may also include an optical interface for receiving input data and may have a selection mechanism to select either the acoustical or the optical input interface to receive data. A communication interface may be provided to communicate with a removable security device such as a smart card and the token may be adapted to generate dynamic security values in cooperation with the removable security device. The acoustic signal received by the token may be modulated using a frequency shift keying modulation scheme using a plurality of coding frequencies to code the acoustical signal where each coding frequency may be an integer multiple of a common base frequency.

A system for controlling a lamp comprises a central controller having a waveform converter capable of modulating a control signal at more than one frequency over a two wire power cable. The control signal is capable of modifying a property of the lamp. The central controller also has a load current sensor capable of identifying the configuration of the lamp. The system further comprises a lighting control unit coupled to the lamp. The lighting control unit is powered via the two wire power cable and is capable of demodulating the control signal.

A receiver assembly (16) includes an amplitude shift keyed mode (52) and a frequency shift keyed mode (58) selectively engagable to receive radio frequency transmissions from the tire monitoring system (26) and a remote keyless entry system (20) and switches between modes in response to receipt of a wake up pattern.

A estimating method of OFDM communication system carrier frequency excursion, in original place of systems frame adds two training sequence that were designed especially, using the result of cross correlation of class A training sequence estimates original value of frequency excursion, namely to make rough estimation of frequency excursion, then using class B makes autocorrelation, gained frequency deviation signal was estimated precisely in small scale, namely to make frequency excursion precise estimation, then make two estimating value combined to get precise value of system frequency excursion, finally control numerical control oscillator to produce rectify value of system frequency excursion, and put it to multiply with time domain data to make compensation of frequency excursion.

A phase-locked loop (PLL) keeps tracking a reference clock when a frequency offset is introduced. The PLL has primary and secondary PLL loops. A digital-to-analog converter (DAC) generates a current that is passed through an offset resistor to generate an offset voltage. An op amp is inserted in the primary loop between a filter capacitor and a voltage-controlled oscillator (VCO). The offset resistor is coupled between the inverting input of the op amp and the op amp's output. When the DAC offset occurs, the voltage to the VCO and the frequency of the primary loop change and the primary loop loses tracking of the reference clock. The secondary loop keeps tracking the reference clock during the DAC offset while the primary loop is open. Then the output clock of the secondary loop is applied as the feedback clock to the phase comparator of the primary loop.

A mobile communication system has a plurality of mobile stations and a base station which includes a plurality of antennas, a frequency shift portion, a combining portion, a receiving portion and a signal processing portion. The antenna receives radio waves transmitted by the mobile stations. The frequency shift portion shifts the received signal with a frequency corresponding to each of the antennas. The combining portion determines the shifted signal as a combining signal. The receiving portion converts the combining signal in frequency to make an intermediate frequency signal, and converts the intermediate frequency signal into a digital signal. The signal processing portion includes spreading demodulation means judging means, and fading compensation means.

The invention discloses a method for realizing setting of a navigating destination through bluetooth push-to-talk. The method is characterized by comprising the following steps of: firstly, starting a push-to-talk device which is connected with a bluetooth module; after matching the bluetooth module with a user mobile phone, dialing a background system phone number by the user mobile phone; after answering the call and understanding a user requirement by a telephone operator of the background system, operating the background system and encoding through DTMF/FSK (Dual Tone Multiple Frequency/Frequency Shift Keying) coder and decoder; returning voice signal data corresponding to map coordinate data to the user mobile phone through a mobile phone network; after receiving the voice signal data by the user mobile phone, sending the voice signal data to the DTMF/FSK decoder in the manner of mobile phone bluetooth; after decoding by the DTMF/FSK decoder, storing in a vehicle master controller MCU (Micro Controller Unit); and lastly, extracting map coordinate information from a memory by a navigating system in a vehicle-mounted terminal and starting a navigating service. The method provided by the invention has the advantages of low cost, high decoding speed and excellent popularizing value.

The invention discloses an analog-digital mixing modulation recognition device and a digital modulation recognition device based on parallel judgment, belonging to the communication field. The invention aims to solve the problems of low precision rate and long recognition time for providing a judgment tree by A.K. N and E.E.A zzouz. The invention is characterized in that the parallelly judged analog-digital mixing modulation recognition device comprises the following steps: a modulation signal receiving module coarsely classifies the received modulation signals through an instantaneous characteristic normalization module and a modulation mode characteristic parameter extraction module, and then the received modulation signals are particularly classified through an amplitude shift keying modulation judgment ouput module, a phase shift keying modulation judgment output module and a frequency shift keying modulation judgment output module. Compared with the analog-digital mixing modulation recognition device, the digital modulation signals received by the digital modulation recognition device based on parallel judgment have different inner structures of the modules when coarse classification and particular classification are conducted.

Described are an FSK modulator and a method for large-alphabet FSK modulation. The FSK modulator and the method are based on filtering of a multi-tone optical source such as a mode-locked laser which provides a comb distribution of tones. A frequency-selective component selects for transmission a subset of the tones. In various embodiments the frequency-selective component is a Mach-Zehnder interferometer filter or a microring resonator filter. A second frequency-selective component selects a subset of the tones from the comb distribution provided by the first frequency-selective component. Still more frequency-selective components can be used according to the number of tones supplied by the multi-tone optical source to the FSK modulator. The optical signal exiting the last frequency-selective component includes only a single tone which corresponds to the symbol to be transmitted.

A long range wireless phasing voltmeter determines the phase difference between the time-varying voltage carried on a reference electrical conductor and another, field conductor. The voltage signal from the reference conductor is measured by a reference probe and compared by a first unit in communication with that reference probe to a precision 60 Hz signal generated from a GPS receiver. The phase difference between these, in the form of a nine-bit, audible signal using frequency shift keying to modulate the carrier frequency, is transmitted by the first unit to a second unit perhaps miles away. A receiver in the second unit decodes the signal and uses another precision 60 Hz signal generated from another GPS receiver to re-create a surrogate of the original reference voltage signal. This surrogate signal is forwarded to a meter probe that is measuring the signal on a field conductor. The meter probe can then compare the two signals to determine the phase angle difference between them.

The aim of the invention is to provide an individual identification method of an FSK (frequency-shift keying) signal based on slice bi-spectrum and wavelet transformation. The method comprises the following steps: carrying out bi-spectrum and slice bi-spectrum analysis on the received signal to obtain a spectrogram of the slice bi-spectrum of the signal; respectively building envelope parameter characteristic databases under different signal to noise ratios; carrying out wavelet transformation on the received signal, and extracting a mean value of low-frequency wavelet coefficients; simultaneously building characteristic databases of 4FSK signals of different M numbers and different modulation parameters under different signal to noise ratios; fusing the slice bi-spectrum envelope parameter characteristics and the low-frequency wavelet coefficients; identifying the modulation type of the FSK signal, and achieving individual identification of the 4FSK signals of different parameters by the same signal processing process. According to the individual identification method, the defects of high requirements on the signal to noise ratios of the existing class modulation identification method can be overcome, and individual identification on the FSK signal is carried out in real time under the conditions of low signal to noise ratio and less priori knowledge.

The invention provides a home appliance information communication system of asymmetric power line carrier and wireless communication. The system comprises an electric energy meter gateway, a ZB-APLC (zinc borate-active power line conditioner) and a white information home appliance, wherein the white information home appliance comprises an APLC standard white information home appliance and a ZigBee standard white information home appliance; an APLC communication circuit of the APLC electric energy meter gateway is arranged in an electric energy meter, and the APLC electric energy meter gateway is accessed between a phase line and an N phase of a three-phase four-wire system at a lower voltage side of a 10kV/0.4kV distribution transformer of an electric power system; a ZB-APLC network bridge is electrically connected with the load of the white information home appliance, and the ZB-APLC network bridge is accessed into the electric system by the APLC electric energy meter gateway; digital communication is performed between the APLC electric energy meter gateway and the ZB-APLC network bridge by the asymmetric power line carrier communication, the communication between the APLC electric energy meter gateway and the ZB-APLC network bridge adopts a voltage type FSK (frequency shift keying) or S-FSK (spread frequency shift keying) modulating signal, and the communication between the ZB-APLC network bridge and the APLC electric energy meter gateway adopts a current type FSK or S-FSK modulating signal; and the information exchange between the ZB-APLC network bridge and the ZigBee standard white information home appliance can be realized by the ZigBee wireless communication.

A method of communication utilizing the Public Switch Telephone Network (PSTN) and the Internet is disclosed which includes receiving on a database server, a query transmitted from a first computer, which query includes a set of instructions encapsulated in a string of data including a telephone number, time, date and a short fifteen character message that will be accessed by a third computer which is running a telephone soft switch server, the soft switch server will then place a call to the telephone number and deliver the string of data using Frequency Shift Keying (FSK) and SMS even while the recipient's phone is ringing or while off hook as call wait caller id (CWCID).

Executing a FOTA (firmware over the air) method in a LoRa network having low throughput and low power. the transceivers used in the end nodes and in the LoRa gateway are capable of selecting a certain frequency channel and deactivating the LoRa mode. If the spread-spectrum LoRa mode is deactivated, both transceivers at the end node and the gateway function instead using a basic FSK (frequency-shift keying) modulation scheme. This modulation scheme is capable of providing a higher data rate at the expense of reducing the “path balance,” which indicates how much attenuation the transmitted signal may sustain while still being able to be decoded at the receiver. When using the FSK modulation scheme at a high data rate, a FOTA method may be easily carried out, since the end node must have its receiver activated only for a short time.

An enhanced services display message protocol (ESDMP) facilitates display of messages in a compliant analog telephony device (ATD). An exemplary gateway device in a voice over packet (VOP) network can activate enhanced services in a compliant ATD using the ESDMP and includes a controller and first and second interfaces. One of the interfaces can transmit and receive communications over a VOP network. The other interface can transmit and receive voice band message data modulated according to a frequency shift keying (FSK) protocol. The ESDMP can be used to configure the gateway to activate features supported by the ATD, to update call state information and to display feature state information.

A digital nonlinear adaptive mechanism for frequency offset compensation for use in a digital Frequency Shift Keying (FSK) receiver such as a Bluetooth GFSK receiver. The mechanism is intended to aid in the recovery of a frequency-modulated signal in the presence of an unknown additive frequency offset, which could be greater than the peak frequency deviation and which must be suppressed to enable proper data recovery in the receiver. The mechanism utilizes a demodulator to convert the frequency offset into a digitally represented DC level. This level is extracted by a non-linear estimator based on peak detectors and filters. Active suppression of the DC level is achieved by feed-forwarding the estimated value into a subtractor that removes it from the digital signal. A gear shift mechanism incorporated within the DC estimation block enables the dynamic control of the DC estimation process. Charge and discharge coefficients are configured dynamically to provide fast frequency offset compensation during the reception of the redundant header at the beginning of a packet and relatively slow frequency offset compensation during the subsequent reception of the payload portion of the packet, thus minimizing both the acquisition time and the payload's BER in the receiver.

An optical FSK modulator which can be used for an optical information communication is provided. The optical FSK is provided with: a second sub Mach-Zehnder waveguide (MZ_B) 3; a main Mach-Zehnder waveguide (MZ_C) 4 including the MZ_A and MZ_B and provided with a light input portion and a modulated light output portion; a first direct-current or low-frequency electrode (DC_A electrode) 5 controlling a bias voltage between two arms composing the MZ_A, thereby controlling a phase of light propagating in the two arms of the MZ_A; a second direct-current or low-frequency electrode (DC_B electrode) 6 controlling a bias voltage between two arms composing the MZ_B, thereby controlling a phase of light propagating in the two arms of the MZ_B; a first RF electrode (RF_A electrode) 7 inputting a radio frequency (RF) signal to the two arms composing the MZ_A; a second RF electrode (RF_B electrode) 8 inputting an RF signal to the two arms composing the MZ_B; and a traveling-wave-type electrode (RF_C electrode) 11 controlling a voltage of the RF signal inputted, thereby controlling a frequency of light outputted from the output portion.

The invention relates to an optical signal receiving method, an optical signal receiving device and an optical transmission system; the method comprises the following steps: receiving a 16QAM optical signal and local oscillator light, carrying out coherent detection to the signal and the light to obtain a 16QAM signal; according to the nonlinear phase shift factor and the drift phase error make-up corresponding to a previous 16QAM signal, pre-compensating for the phase of a current 16QAM signal, calculating the nonlinear phase shift factor and the shift phase error corresponding to the current 16QAM and takes the same as the nonlinear phase shift factor and the shift phase error required by compensating for a next 16QAM signal. The realization of the embodiment of the invention not only can effectively compensate for the shift phase error caused by frequency shift and phase shift between optical carrier and the local oscillator light, but also can compensate for the nonlinear phase shift of the 16QAM optical signal when transmitted in an optical fiber caused by nonlinear effect, thereby greatly reducing the error rate of the system and not producing format effect.

The invention discloses a remote control key, tire pressure monitoring and engine anti-theft locking system, which comprises an automobile body controller, a tire pressure monitoring module, a remote control key module and an engine anti-theft locking module, wherein on the basis of the system integration technology, an automobile remote control entry system, an engine anti-theft locking system and a tire pressure monitoring system are combined into a whole, and the hardware redundancy is reduced. The remote control key module and the tire pressure monitoring module are connected with the automobile body controller in a wireless way of 434MHz, and the engine anti-theft locking module is connected with the automobile body controller in a low-frequency wireless way of 125MHz. Wireless data emitted by the remote control key and the tire pressure monitoring module adopts a 434MHz frequency range, a frequency shift keying modulation mode and a Manchester data encoding mode. The remote control key data after the Keeloq rolling code encryption is distinguished from the tire pressure monitoring data through matching codes. The system has the advantages that the hardware redundancy is reduced, the cost is low, the failure rate is low, and the space size is small.