Abstract: A method and telecommunications system for identifying uplink multiplexing resources of a multi-beam satellite that are usable in a land-based telecommunications system, e.g., a transmitting station for transmitting radio signals to a receiving station. The transmitting station or the receiving station being a base station having a range defining a coverage area. For a given uplink multiplexing resource, a maximum allowable interference level, with respect to the satellite, for radio-electric signals transmitted from the coverage area is estimated. A potential interference level of the transmitting station is estimated. The transmitting station determines the usability of the given uplink multiplexing resource by comparing the potential interference level with the maximum allowed interference level for the given uplink multiplexing resource.

Abstract: Various embodiments are directed to systems and methods for combining a plurality of codes. The plurality of codes may be binary codes having possible logical values of ?1 and +1 and may comprise an even number of codes. An output of the combining v0,k may be given by: v0=sgn(vi), where vi is the sum of the first plurality of codes at the first time. Embodiments for allocating different power levels among various codes are presented.

Abstract: An electronic device (100) and method for operating the same. The electronic device (100) comprises at least two working modes and comprises a connection state acquisition unit (110) and a mode switching unit (12). The connection state acquisition unit (110) is used for acquiring the connection state between the electronic device (100) and a remote control unit, and the remote control unit is used for remotely controlling the electronic device (100). The mode switching unit (12) is used for switching the working mode of the electronic device (100) according to the connected state.

Abstract: A vehicle powering wireless receiver for use with a first electromagnetic resonator coupled to a power supply. The wireless receiver includes a load configured to power the drive system of a vehicle using electrical power, and a second electromagnetic resonator adapted to be housed upon the vehicle and configured to be coupled to the load, wherein the second electromagnetic resonator is configured to be wirelessly coupled to the first electromagnetic resonator to provide resonant, non-radiative wireless power to the second electromagnetic resonator from the first electromagnetic resonator; and wherein the field of at least one of the first electromagnetic resonator and the second electromagnetic resonator is shaped using a conducting surface to avoid a loss-inducing object.

Abstract: Systems and methods are described to supply positioning reference signal (PRS) in a telecommunication system. A base station supplies a PRS sequence according at least to a time-frequency pattern of modulation symbols, wherein the time-frequency pattern assigns a modulation symbol to each frequency tone in a block of time-frequency resources allocated to transmit PRS. The base station associates a modulation symbol in the time-frequency pattern with a reference symbol in the PRS sequence through a mapping that represents the time-frequency pattern. The PRS sequence is conveyed to user equipment through delivery of a set of modulation symbols established through the mapping. Different time-frequency patterns can be exploited based on time-structure of a radio sub-frame. The user equipment receives the PRS sequence according to at least the time-frequency pattern of modulation symbols and utilizes at least the PRS sequence as part of a process to produce a location estimate.

Abstract: The present invention provides a modulation circuit and a method for modulating a wireless power transfer circuit. The modulation circuit has a switching circuit having a first state and a second state. The modulation circuit also has a modulation mode in which the first state defines a normal state and the second state defines an operative state. In the operative state, the modulation circuit modulates an electrical parameter of the wireless power transfer circuit in a modulation direction. The modulation circuit is configured to apply a trial modulation to the electrical parameter to determine whether the modulation direction is in a desired modulation direction. The modulation circuit is also configured to apply a modulation translation if the modulation direction is not in the desired modulation direction, with the modulation translation changing the modulation mode such that the modulation direction is in the desired modulation direction.

Abstract: Call handoff from an 802.1x network to a cellular network, and vice versa. A wireless device that has both cellular and 802.1x capability detects the strength of a cellular signal and of an 802.1x signal. If a call is taking place over the 802.1x network and the strength of the 802.1x signal drops below a particular level and the strength of the cellular signal is above a certain level, the call is handed off from the 802.1x network to the cellular network. If a call is taking place over the cellular network and the cellular signal strength drops below a certain level while the 802.1x signal strength is above a certain level, the call is handed off from the cellular network to the 802.1x network. In addition, the user of the wireless device can manually initiate the handoff by actuating a handoff selector of the wireless device.

Abstract: An authentication controller coupled to a first communication port of a portable media device is allowed to provide authentication on behalf of an accessory device coupled to a second communication port of the portable media device. In one embodiment, a cross transport connector includes a connector configured to couple with an accessory and a connector configured to couple with a portable media device such that the accessory can be coupled to the second communication port of the portable media device. The cross-transport connector also includes an authentication controller. The authentication controller may request authentication from the media device over the first communication port of the portable media device. The request may also include an identifier of the second port, to which authenticated permissions obtained via the first port may be transferred.

Abstract: In a wireless network that includes a plurality of nodes, a method of maintaining, by a first node, information regarding communications links between nodes in the wireless network includes: for each communications link that is established with another node, recording an identification of the other node; and for each message received by the first node from the other node through the communications link with the other node, recording a network pathway by which the message has been sent in the wireless network, the network pathway identifying the nodes and the communications links therebetween by which the message has been sent. Another method includes recording, by a server, for each message that is received by the server from the wireless network, a network pathway by which the message has been sent, the network pathway identifying the nodes and the communications links therebetween by which the message has been sent.

Abstract: In accordance with an embodiment, a method of operating a base station configured to operate with user devices includes scheduling a first user device in a first slot, scheduling the first user device for at least one further slot, and transmitting an assignment for the at least one further slot to the first user device. The first slot has a first resource block (RB) and a first transmission time interval (TTI) and the at least one further slot has the first RB and a second TTI.

Abstract: A logical channel is configured to match a modulation profile of an active channel. A network element is assigned to the logical channel and a ping request is sent to the network element. A response from the network element is measured, such as measuring the MER. The modulation profile is increased in the logical channel and another ping request is sent to the network element. The response is measured again, and the process is repeated until a non-linearity is detected in the response. The acceptable modulation profiles are indicated before the non-linearity is detected in the response.

Abstract: An authentication controller coupled to a first communication port of a portable media device is allowed to provide authentication on behalf of an accessory device coupled to a second communication port of the portable media device. In one embodiment, a cross transport connector includes a connector configured to couple with an accessory and a connector configured to couple with a portable media device such that the accessory can be coupled to the second communication port of the portable media device. The cross-transport connector also includes an authentication controller. The authentication controller may request authentication from the media device over the first communication port of the portable media device. The request may also include an identifier of the second port, to which authenticated permissions obtained via the first port may be transferred.

Abstract: A method of fighting interference in a frequency-hopping communication system is disclosed. The system has at least one main sensor and one or more auxiliary sensors. According to at least one embodiment, frequency-hopping signals are received. The frequency-hopping signals are arranged to include useful bands and one or more guard bands inserted between the useful bands, and a ratio of the useful bands to the guard bands being chosen according to a predetermined value of probability of interference interception. Signals of the inserted guard bands having a signal level greater than a predetermined threshold are selected. A set of spatial-filtering weightings are calculated according to a correlation matrix of noise plus jammers alone on the signals selected. Baseband signals of the received frequency-hopping signals are filtered by the set of the calculated spatial-filtering weightings.

Abstract: Described herein are methods, devices and systems for characterizing an attached antenna to an electronic device, such as a radio frequency identification (“RFID”) reader. One exemplary embodiment is related to a method comprising outputting a low amplitude modulation (“AM”) index radio frequency (“RF”) waveform, the waveform simulating tag data timing and bandwidth, removing a direct current (“DC”) component from the waveform to create a chopped portion of the waveform, applying at least one vector analyzer technique on the chopped portion of the waveform, characterizing at least one antenna impedance vector of the waveform.

Abstract: Call handoff from an 802.1x network to a cellular network, and vice versa. A wireless device that has both cellular and 802.1x capability detects the strength of a cellular signal and of an 802.1x signal. If a call is taking place over the 802.1x network and the strength of the 802.1x signal drops below a particular level and the strength of the cellular signal is above a certain level, the call is handed off from the 802.1x network to the cellular network. If a call is taking place over the cellular network and the cellular signal strength drops below a certain level while the 802.1x signal strength is above a certain level, the call is handed off from the cellular network to the 802.1x network. In addition, the user of the wireless device can manually initiate the handoff by actuating a handoff selector of the wireless device.

Abstract: A Generalized Rake (G-Rake) receiver is adapted for Golden code reception in a CDMA system. Signals transmitted by two or more transmit antennas are received at two or more receiver antennas. The signal from each receiver antenna is despread, and channel estimation is performed for each transmit antenna. G-Rake combining weights are calculated based on impairment correlation across G-Rake fingers and channel coefficients corresponding to each transmit antenna. The despread values from each symbol period are combined over a plurality of symbol periods based on the combining weights. The combined values are processed using coefficients derived from the Golden number to generate a set of decision variables, and the Golden encoded symbols are jointly detected from the decision variables. In some embodiments, spherical decoding and triangularization significantly simplify the decoding problem formulation.

Abstract: Delay estimation apparatus and method, comprising: a correlation step which a correlation function between a received signal and a supplied template waveform is generated, AD conversion step at which said correlation output generated at said correlation step is uniformly sampled into discrete samples; and arithmetic operation step at which a time delay estimate of the received signal based on said discrete samples generated at said AD conversion step is computed, wherein a selection criterion depending on the digital sampling frequency used at said AD conversion means is checked, if said selection criterion is satisfied, computes the time delay estimate based on the direct pick method, and if said selection criterion does not hold, computes the time delay estimate based on the simplified maximum likelihood (ML) method.

Abstract: There are disclosed a transmission device and a reception device having a high secrecy making it difficult to wire tap by a third device. The transmission device includes a modulation section which can be modulated by a plurality of modulation methods and a transmission section which can transmit a radio signal by using a plurality of carrier frequencies. Moreover, the reception device includes a demodulation device which can demodulate by using a plurality of demodulation methods and a reception section which can receive a radio signal by using a plurality of carrier frequencies. The transmission communication method or the reception communication method is changed as the time elapses by changing the combination of the modulation method or demodulation method and the carrier frequency, thereby transmitting or receiving data.

Abstract: Multi-carrier broadband wireless communication can be supported by providing identification information that identifies a group of carrier frequencies that an intended recipient of a transmission has selected for use in the transmission. A modulation and coding scheme for use in transmitting on the selected group of carrier frequencies is selected based on communication quality information indicative of communication quality associated with transmitting on the selected group of carrier frequencies. Transmission on the selected group of carrier frequencies is performed according to the selected modulation and coding scheme.

Abstract: A system and method for generating dynamically modifiable timing control signals. Timing waveforms can be changed, for each phase of control, by changing the contents of memory locations and start/stop indices. Parallel signals are generated from the output of the memory locations. The memory locations are accessed in a user-selected order by an index value. This technique of generating timing waveforms, and thus control signals, can be applied to, for example, pixel array development.

Abstract: A data communication apparatus includes an antenna, an analog front-end circuit, and a controller. The analog front-end circuit is connected between the antenna and the controller and includes first and second modulators, a driver, a demodulator, and an input switch. The first modulator modulates data to be transmitted to a read-write device as a response to a request from said read-write device and sends the modulated data to the antenna. The second modulation circuit modulates data to be transmitted to other ID tags. The driver amplifies an output from the second modulator to drive the antenna. The demodulator demodulates data sent from the other ID tags and ID-tag read-write devices. The input switch selectively inputs the data to the first or second modulator. This abstract is provided to comply with rules requiring an abstract, and it is submitted with the intention that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: Data encoded in packets modulated onto a carrier wave is transmitted between a base station and a transponder. Each packet includes a header section containing at least a reference symbol, and a further section such as a data section. In the transponder, the time duration of the reference symbol is determined, and a parameter is adjusted dependent on the determined duration. The parameter determines at least a property, such as the time resolution, of the encoding and/or decoding operation, and may be the clock frequency of a counter circuit or the charging current of an RC-circuit used to determine the duration of the symbols. The parameter may initially be set to a minimum default value, which is increased if the determined duration is less than or equal to a specified threshold. Thereby, power consumption is minimized while ensuring reliable encoding and decoding over a large range of transmission distances.

Abstract: A method encodes a sequence of blocks of input bits to be transmitted over a wireless channel. Each block of input bits is converted to a codeword, and each codeword is mapped to multiple sub-blocks of complex numbers. Each sub-block is multiplied by a disambiguating spreading transform to obtain a sub-block of transformed symbols, which can be modulated and transmitted to a receiver, where each received block is demodulated to a block of complex numbers, which are partitioned into sub-blocks. The sub-block of complex numbers are converted to a set of likelihood ratios that correspond to decoded codewords. The input bits can be decoded unambiguously even if only one of the blocks of symbols corresponding to the block of input bits is received correctly.

Abstract: Adaptive modulation/demodulation method in a radio communication system is provided. A modulation multi-level number in a transmission device and a demodulation multi-level number in a reception device are judged independently from each other according to a propagation condition and communication is performed by controlling the likelihood when the multi-level numbers of the transmission side and the reception side are different. The reception device can perform operation by controlling likelihood information on lower bit of the multi-level modulation even when the modulation multi-level number and the demodulation multi-level number used at the transmission side are different. Moreover, the transmission device and the reception device independently decide the modulation multi-level number and the demodulation multi-level number, thereby following an instantaneous propagation fluctuation and improving the throughput.

Abstract: The present invention provides ultra-wide band communication systems and methods, including multi-band ultra-wide band communication systems and methods. Methods and systems are provided in which frequency sub-bands of an ultra-wide band spectrum are allocated for signal transmission. An ultra-wide band transmission including the information is sent, including sending a signal over each of the plurality of sub-bands. Methods are further provided in which a first data signal containing information is converted into an encoded signal using an Inverse Fast Fourier Transform. The encoded signal is converted into an encoded ultra-wide band signal that can be pulsed or transmitted using burst symbol cycles. The encoded pulsed ultra-wide band signal is decoded using a Fast Fourier Transform to obtain the information.

Abstract: The invention relates to a new design of discharge vessel for a discharge lamp, in which dielectrically impeded discharges are to be generated. In this case, a discharge vessel plate 1, 9 is, as it were, of two-fold design, specifically as a first discharge vessel plate 1 with an external electrode set and, in addition, as a stabilizing plate 9 outside the first discharge vessel plate 1.

Abstract: A transmission circuit includes a baseband circuit, spreading section, multiplier, digital modulator, quadrature modulator, and antenna. The baseband circuit generates and outputs at least one transmission data constituted by first and second channel data. The spreading section spreads the transmission data with a spreading code that differs for each transmission channel. The multiplier respectively weights the amplitudes of the first and second channel data by using a combination of two gain factors determined by a transmission data rate. The digital modulator digitally modulates the first and second channel data whose amplitudes are weighted by the multiplier. The quadrature modulator quadrature-modulates the digitally modulated first and second channel data and outputs the data as a transmission signal. The antenna emits the transmission signal output from the quadrature modulator as a radio wave.

Abstract: For a terminal for mobile communication which includes a display device it is proposed to save energy by arranging a control device so as to disconnect at least a part of the display device in dependence on a relevant operating state.

Abstract: A communications device such as a personal identity card is in the form of a badge or label worn on the outside of the wearer's clothing. The badge includes a first layer of a transparent material having an inner surface that is contoured with a retroreflecting repeating pattern. A second layer also of a transparent material has an inner surface with a reciprocating retroreflecting pattern. Sandwiched between the two layers is a layer of liquid crystal material the refractive index of which can be varied through the application of an electric field. When the refractive index of the layer is close to that of the first and second layers, incident radiation passes through the device with little scattering. However, as the refractive index of the layer is varied by application of an electric field, incident radiation is retroreflected from the contoured interface of the first layer with the layer.

Abstract: A portable telephone system comprising first portable telephone terminal, second portable telephone terminal and a server for performing a management of position information of the first portable telephone terminal. The server is a relay server for position search service and registers into a password managing data base a password for allowing the second portable telephone terminal to search the position of the first portable telephone terminal in advance. The first portable telephone terminal notifies the password registered in the password managing data base to the second portable telephone terminal with a mail or the like. The second portable telephone terminal achieving the password transmits a position search request message to the server. The server checks the password indicated by the search request message, allows the position search and issues a search instructing message to the first portable telephone terminal.

Abstract: A frequency modulator having variable carrier frequency is provided. A VCO frequency-modulates an oscillator input signal using an oscillation frequency set by a set signal as the carrier frequency. A phase/frequency detector outputs phase and frequency differences between a VCO output signal and a reference signal. A filter receives a phase/frequency detector output and generates the set signal. An amplifier generates a pair of output signals whose voltage levels change in opposite directions. A compensation circuit changes the voltage levels of the output signal pair and provides resulting signals to the VCO as the oscillator input signal.

Abstract: The present system increases the number of channels in a given communication band by using narrow or very narrow band frequency modulation (FM) or phase modulation (PM). The system also improves sound quality, increases the signal-to-noise ratio, increases the power of the transmitted information, and/or achieves high selectivity, high fidelity and/or low distortion. Narrow band FM or PM signal communication can be implemented by transmitting a signal with a narrow or very narrow frequency spectrum, receiving the signal, converting the received signal to an IF (intermediate frequency) signal, and then expanding the narrow frequency deviation of the FM or PM signal. The narrow band frequency deviation may be expanded by frequency-multiplying the IF signal. A discriminator may then convert the frequency-deviation-multiplied signal to a low frequency signal or audio signal for further processing.

Abstract: A system and a method for transfer of a digital information carrying signal 51 between an input of a transmitter and an output of a receiver. The information carrying signal is modulated in a modulator included in the transmitter 12, and the modulated signal is transmitted via a transmission medium 13 by transmission means 25 connected to the modulator. The transmitted signal is received by receiving means 41 included in the receiver, and the received signal is demodulated in a demodulator. The information carrying signal is modulated in the modulator with a predetermined first modulation index h0, adapted for efficient use of an available bandwidth of said transmission medium. In the receiver 14 a frequency signal 63 is created from the received signal. Further, the frequency signal 63 is amplified with a factor A, for creating a scaled frequency signal 64, from which a scaled phase signal 65 is created.

Abstract: A method and apparatus for continuously calibrating the modulation sensitivity of a voltage controlled oscillator (VCO) within a modulator of a transmitter. In accordance with the present invention, the transmitter is coupled to the receiver in order to loop back the transmit signal. The present invention includes a baseband signal generator which generates a reference baseband signal of known amplitude during periods when no other baseband information is being applied to the transmitter by the user. A Signal and Reference Comparison Circuit (SRCC) receives the output from the demodulator and determines whether the VCO within the transmitter has the proper modulation sensitivity. If the modulation sensitivity of the VCO is not within a desired range, then a signal generated by the SRCC is applied to a baseband level control circuit to adjust the level of the baseband signal that is applied to the VCO.

Abstract: A frequency modulation (FM) radio transmitter, such as a cellular telephone, includes an automatic deviation control system to automatically compensate for varying sensitivity of the FM transmitter. The FM transmitter includes a phase lock loop including a controlled oscillator that produces a frequency modulated input signal on an output channel frequency in response to a control input that is applied thereto. A scaler is responsive to the input signal and to at least one scaling content, to scale the input signal based upon the at least one scaling constant and to provide the scaled input signal to the phase lock loop to produce the frequency modulated input signal on the channel frequency. An automatic deviation control system measures the control signal that is applied to the controlled oscillator when tuned to one of the plurality of output channel frequencies and updates at least one of the scaling constants based upon the measured control input, to thereby provide automatic deviation control.

Abstract: In a hierarchical micro/macro-cell network, a mobile station will be handed over from a microcell to a macrocell if a number of microcells recognize the mobile station as fast, so that the fast moving mobile stations do not cause a considerable number of handovers between microcells, which make the call control difficult. However, in order to avoid unnecessary switches up to macrocells, a mobile station and the call are handed over to a macrocell only when the mobile station is recognized as fast in a sufficient number of microcells.

Abstract: A method and arrangement for transfer between a cordless telecommunication system, preferably DECT, and a cellular mobile telecommunication system, preferably GSM. The cordless telecommunication system includes of a number of cells within a relatively small area, while the mobile telecommunication system includes of a number of cells within a relatively larger area which completely or partly overlaps the area of the cordless system. The system comprises at least one portable terminal capable of communicating with both the cordless and cellular communication systems. Accordingly a transfer zone is fixed by the cordless system and the terminal is monitored with regard to it identity and position so that transfer parameters can be transmitted to the terminal when it is located in the transfer zone. The transfer is prepared by setting up a three-party connection between the terminal and the telecommunication system and between the terminal and the mobile telecommunication system.

Abstract: A transceiver uses feedback control to monitor a transmitted continuous phase modulation (CPM) waveform, such as a spread spectrum CPM waveform, and adjust the modulation index in response thereto. Codewords are selected from a table according to a data signal and applied to a pulse shaping network. The pulse shaping network outputs a CPM waveform to a prefilter. The prefilter is connected to an FM modulator, such as a voltage controlled oscillator. In one embodiment, a correlator in the transceiver monitors the transmitted waveform during times when the transceiver is not receiving signals, and provides a correlation signal to a feedback control circuit. The feedback control circuit dynamically adjusts the gain of the prefilter, and may comprise, e.g., a second order tracking loop filter. The feedback control signal thereby tracks the amplitude of the transmitted waveform and adjusts the output gain of the prefilter so as to maintain a constant signal envelope.

Abstract: Continuous phase modulated (CPM) signals, such as quaternary CPFSK signals, are filtered to limit their bandwidth while simultaneously minimizing the amount of amplitude modulation and intersymbol interference introduced by this filtering process. By designing a modulation filter such as a finite impulse response (FIR) filter to add only a nominal, controlled amount of amplitude modulation, high efficiency, nonlinear power amplifiers may be employed to transmit the filtered CPFSK signals. Although the filter adds a small amount of amplitude modulation and intersymbol interference, digital signal processor-based receivers satisfactorily demodulate this type of signal using sequence estimation algorithms such as the Viterbi algorithm. Thus, the filtering of CPM signals permits narrowing of the transmitted signal spectrum while managing the intersymbol interference resulting from the controlled amount of amplitude modulation added by filtering.

Abstract: In a frequency modulator (1) having an adjusting circuit by which frequency modulator an applied luminance signal of a color video signal that contains synchronization pulses is frequency modulated, while the chrominance signal of the color video signal is modulated on a carrier, that has a quiescent frequency if no color information is available. A capacitor is provided for an automatic mode of operation, and is charged or discharged, respectively, in dependence on the period duration of the modulator output signal and in dependence on the period duration of the quiescent frequency of the chrominance carrier.

Abstract: A dual-mode transmitter (100) adjusts a signal's deviation level when switched between a wideband mode and a narrowband mode of operation. The transmitter (100) automatically attenuates the deviation of the signal based on a ratio of the maximum deviation level for the wideband mode to the maximum deviation for the narrowband mode utilizing wideband/narrowband maximum deviation adjust circuitry (115). Because the attenuation based on the ratio of the maximum deviation levels is too large for a narrowband mode signal having average deviation, the signal is amplified based on a ratio of the average deviation level for the wideband mode to the average deviation for the narrowband mode utilizing wideband/narrowband average deviation adjust circuitry (103). Attenuation and amplification of the signal's deviation occur when the dual-mode transmitter (100) is operating in the narrowband mode.

Abstract: A radiotelephone includes a multifunctional headset that operates in two different modes. According to a first mode, the headset may be mounted on a radiotelephone body where it serves as a speaker and microphone for the radiotelephone. Also, the headset can be separated from the body of the portable radiotelephone and placed on the head of the user. In this mode of operation, the headset receives and transmits signals from and to the radiotelephone body during a call, thus providing hands-free operation. The headset can be attached to a user's head by an ear clip. The headset and body may include low power RF transceivers. The headset may contain power saving circuitry to minimize power drain from an internal battery. The battery may be recharged whenever the headset is fixed to the radiotelephone.

Abstract: Applicant's invention includes an apparatus and associated method for transmitting information at a high rate using an undermodulated frequency shift keyed signal. The transmission rate is independent of the data content and the system requires no zero crossing detectors. The demodulator combines non-linear processing circuitry with a conventional demodulator.

Abstract: A base station is provided which supervises the quality of a radio link and including a generator circuit for generating a supervising signal having a desired baseband frequency, a measuring circuit for monitoring the level of the baseband supervising signal, and a transmitting circuit for frequency-modulating a transmitting-frequency carrier of said baseband supervising signal. The measuring circuit comprises an A/D converter for deriving digital sample values from the baseband supervising signal, and a control circuit which monitors the deviation of sample values from that of a digital sample value corresponding to a supervising signal level causing a desired deviation in the output signal of the transmitting circuit on the basis of at least one reference value stored in a memory in connection with the calibration so that the deviation is no more than a predetermined difference value.

Abstract: Apparatus for synthesising a composite signal (53) which has spaced first and second frequency channels of which each has an independently predetermined power, the power of the first channel being substantially below that of the second, and each channel being frequency modulated by an independent signal, the apparatus including a generator (51) responsive to the independent signals and to representations of the said powers and to the channel spacing to generate a composite modulation signal, and a single, high purity radio frequency source (52) connected for modulation by the output of the composite modulation signal-generating generator to produce the composite signal (53).

Abstract: Improved effifiency of frequency-modulated (FM) transmission of signals through analog channels, i.e., achievement of a higher bandwidth and/or signal-to-noise ratio (SNR) in the received signal for a given channel bandwidth and channel carrier-to-noise ratio (CNR), is accomplished by adaptive adjustment of the modulation index in such a manner that the spectrum of the channel signal more nearly occupies the entire channel more of the time than it would otherwise. Data is transmitted, along with the signal, to enable the receiver to calculate the modulation index at each instant so that the signal can be properly demodulated. The invention has application to FM transmission of signals representing visual image or other information, such as sound, for which human perception of noise is greatest in areas of low amplitude and/or frequency and reduced in and immediately adjacent to areas of high amplitude and/or frequency.

Abstract: An automatic deviation control circuit for an angle modulated data transmitter is disclosed wherein the deviation level of modulated data is controlled by a modulation cancelling deviation error detection feedback loop. After the modulation is cancelled from a sample of modulated carrier by a predetermined value of deviation, residual modulation is detected, sampled following a predetermined number of like-level data bits, and applied to the modulation path gain to increase or decrease the deviation such that the residual modulation is minimized.

Abstract: A phase lock loop having an instruction input to which is applied the output signal of the frequency-modulated variable frequency oscillator. The pass band of the loop is regulated in order to obtain at its output, a frequency-filtered signal corresponding to the frequency-modulated signal applied to the instruction input. A phase demodulator having inputs coupled to the instruction input of the loop and to the output of the loop supplies a signal corresponding to the modulation index of the signal supplied by the oscillator. This signal is compared with a reference signal by a comparator circuit, which supplies a control signal to means for adjusting the amplitude of the modulating signal applied to the input of the oscillator, in order to permanently adjust the modulation index of the frequency-modulated signal, produced at the output of the oscillator, to the value of the desired modulation index corresponding to the reference signal.

Abstract: In a system for frequency-diversity transmission, separate and distinct frequency carriers are obtained from the frequency modulation of an oscillator by a pure frequency with an index such that a certain number of Bessel lines thus obtained constitute a corresponding number of separate carriers. All the carriers are subsequently modulated by the information, then power-amplified in a single amplifier having a peak power equal to that of a single signal whose effective power would be the sum of those of the separate carriers. By means of this system, equipment for radio communication by tropospheric or ionospheric scatter propagation can be constructed in a simple manner and at low cost, with a high diversity order.

Abstract: In apparatus for receiving a television signal which is made by a frequency-modulation by a video signal, the improvement is that a band-pass filter provided in the receiver for selectively taking out selected television signal is designed in a manner to have a center frequency shifted from a frequency corresponding to the center level of the video signal to the side of another frequency corresponding to white-signal level, so that noises of the picture in small signal receiving is decreased.