Abstract: A method in a network node and an apparatus for determining passive intermodulation (PIM) characteristics at the network node are provided. According to one aspect, a method includes capturing signals from each of at least one antenna port at a first time and a second time. The method includes determining a first covariance matrix based on signals captured at the first time. The method also includes determining a second covariance matrix based on signals captured at the second time. The method further includes determining a difference matrix, the difference matrix being based on a difference between the first and second covariance matrices, the difference matrix corresponding to changes in PIM between the first time and the second time.

Abstract: A power converter includes a primary circuit and a secondary circuit. The primary circuit includes two primary LC circuits that are in parallel electrically with each other. A first node of each primary LC circuit is electrically coupled to a high-voltage input. A second node of each primary LC circuit is coupled to a respective terminal of a primary inductor that forms a transformer with a secondary inductor in the secondary circuit. Each primary LC circuit is electrically coupled to a primary switch that operates at approximately the resonance frequency of the primary LC circuits to output an alternating current that passes through the primary inductor. The terminals of the secondary inductor are coupled to respective secondary switches. The switches operate at the resonance frequency of the primary LC circuit to rectify the power. A low-pass filter outputs the mean of the received voltage.

Abstract: A signal interference cancellation system includes a signal filter that receives an interference signal and is in communication with a receiver that also receives the interference signal. The signal filter includes (a) a modulation system that modulates the interference signal to generate a modulated signal, (b) a first frequency range within which the modulation system amplifies quadrature components of the modulated signal, (c) a second frequency range within which the modulation system amplifies non-quadrature components of the modulated signal, and (d) a signal adder that combines the amplified quadrature and non-quadrature components of the modulated signal from (b) and (c) to generate an interference cancellation signal. The signal filter communicates the interference cancellation signal to the receiver for cancelling the interference signal.

Abstract: A method is provided for automatically providing remote services for a mobile device having an established relationship with a server of a home network. After the relationship between the mobile device and the server has been set-up and the device detects a local network that is separate and remote from the home network, a connection is automatically established between the mobile device and a local network. The device then automatically establishes an Internet connection with the server through the local network, and transmits to the server information that was stored in the mobile device when the relationship was established. In response to the server recognizing the device through the transmitted information, the server automatically activates at least one service to initiate a transfer data, such as uploading images between the device and the server through the local network.

Abstract: A base station device may include, but is not limited to: a mapping unit; and at least one reception antenna. The mapping unit is configured to assign a plurality of first subcarriers to a first communication device, and assign a part of the plurality of first subcarriers to at least one other communication device. The at least one reception antenna is configured to receive from one of the first communication device and the at least one other communication device, a plurality of frequency signals allocated to the plurality of first subcarriers. Each of the plurality of frequency signals is converted from coded transmission data of the one of the first communication device and the at least one other communication device.

Abstract: In one embodiment, a method is provided for providing power to a radio-frequency (RF) component capable of operating under multiple communication standards, wherein each standard has a respective operating frequency. The method includes: receiving a communication standard signal indicative of which of the multiple communication standards the RF component is currently operating under; selecting a frequency for a power converter system in response to the communication standard signal, wherein the selected frequency is higher than a baseband frequency of the current communication standard for the RF component; generating an oscillation signal having the selected frequency; and operating the power converter system with the oscillation signal having the selected frequency to provide power to the RF component, wherein the operation of the power converter system causes minimal interference with the RF component operating under the current communication standard.

Abstract: A wideband telecommunications device with narrow band support. The device may be a receiver having a wireless interface configured to receive combined first and second signals, the first signal having data in a first frequency band and the second signal having data in a second frequency band wider than the first frequency band, wherein the first frequency band is within the second frequency band. The receiver may also be a processing system configured to recover the data in the first signal from the combined first and second signals.

Abstract: A system for processing signals is disclosed and may include a single chip having an integrated Bluetooth radio and an integrated FM radio. The single chip may include at least one processor that enables selecting from a range of FM channels, a particular frequency for one of the FM channels based on an intermediate frequency (IF). The particular frequency may be selected so that it is an integer multiple of a channel spacing between neighboring allocated FM channels within the range of FM channels, and may be offset by at most one-half the channel spacing. The at least one processor may enable determining a frequency error of the selected particular frequency for the one of the FM channels. The at least one processor may also enable determining, whether the particular frequency includes an on-frequency channel based on the determined frequency error.

Abstract: A signal relay apparatus, method, application program, and computer readable medium adapted for wireless network are capable of saving power consumption due to failure of adjusting amplifying gain dynamically and solving the difficulty of demodulation since noise is also amplified during relay. For wireless access network, the present invention decreases the transmission power of mobile devices so that the battery of the mobile devices may keep working longer and the interference inside is reduced.

Abstract: A two-point modulation type phase apparatus and a wireless communication apparatus capable of achieving a reduction in circuit scale and low power consumption while maintaining modulation precision.

Abstract: In one embodiment, a method is provided for providing power to a radio-frequency (RF) component capable of operating under multiple communication standards, wherein each standard has a respective operating frequency.

Abstract: An RF transceiver includes a low noise amplifier module, a blocking circuit, a down-conversion module, a processing module, an up-conversion module, and a power amplifier module. The low noise amplifier module amplifies inbound RF signals. The blocking circuit, when enabled, substantially attenuates a blocking signal and passes, substantially unattenuated, desired receive RF signals of the inbound RF signals. The down-conversion module converts the amplified inbound RF signals or the desired receive RF signals into inbound baseband or low IF signals. The processing module converts the inbound baseband or low IF signals into inbound data, converts outbound data into outbound baseband or low IF signals, determines a transmit power level, and determines whether to enable the blocking circuit based on the transmit power level. The up-conversion module converts the outbound baseband or low IF signals into outbound RF signals, which are amplified by the power amplifier module.

Abstract: An embodiment of the invention provides a method for classifying a received signal. The method includes determining a covariance matrix of signal values of the received signal, and determining an eigenvalue matrix of the covariance matrix. The eigenvalue matrix includes the eigenvalues of the covariance matrix. A first function is determined from at least one eigenvalue of the eigenvalues of the covariance matrix. A second function is determined from at least one eigenvalue of the eigenvalues of the covariance matrix, wherein the second function is different from the first function. Dependent from a comparison between a value of the first function and a value of the second function, the received signal is classified into a signal comprising data or into a noise signal.

Abstract: A method of tracking short-range wireless communication in a vehicle. The method includes tracking a total usage time of a short-range wireless connection between a telematics unit and a portable wireless communication device, sending the tracked total usage time from the telematics unit to a call center via a wireless connection and generating a usage bill at the call center based on the total usage time.

Abstract: A method (200) for controlling audio signals to an FM transmitter and a loudspeaker of a hands-free adapter first sends a first audio signal to the loudspeaker (242) and measures and records a loudspeaker audible artifact such as echo return loss (244) and/or echo tail length (246). Next, the hands-free adapter sends a second audio signal to the FM transmitter and the loudspeaker (252) and measures and records an FM transmitter and loudspeaker audible artifact such as echo return loss (254) and/or echo tail length (256). If the FM transmitter and loudspeaker audible artifact minus the loudspeaker audible artifact is greater than a threshold (263, 266), the hands-free adapter sends a third audio signal to the FM transmitter only (270), and if the FM transmitter and loudspeaker audible artifact minus the loudspeaker audible artifact is not greater than the threshold, the hands-free adapter sends the third audio signal to both the FM transmitter and the loudspeaker (280).

Abstract: A cosite interference rejection system allows cancellation of large interfering signals with an optical cancellation subsystem. The rejection system includes an interference subsystem coupled to a transmit system, where the interference subsystem weights a sampled transmit signal based on a feedback signal such that the weighted signal is out of phase with the sampled transmit signal. The optical cancellation subsystem is coupled to the interference subsystem and a receive antenna. The optical cancellation subsystem converts an optical signal into a desired receive signal based on an interfering coupled signal and the weighted signal. The weighted signal is therefore used to drive the optical cancellation subsystem. The rejection system further includes a feedback loop for providing the feedback signal to the interference subsystem based on the desired receive signal.

Abstract: An FSK receiving apparatus has, as means for performing offset correction upon a demodulated base band signal, a second low pass filter 9 for integrating the demodulated base band signal; a window comparator for detecting a DC offset component in an output voltage from the second low pass filter 9; an up/down counter 11 for incrementing or decrementing a count value on the basis of the output of the window comparator 10; a clock generating portion 13 for generating a timing signal for counting operation in the up/down counter 11; a reference voltage generating portion 12 for generating a reference voltage for a comparator 7 on the basis of the output of the up/down counter 11; and a charging circuit 22 for supplying a reference voltage in the last frame to the second low pass filter 9 so as to charge the second low pass filter 9 with the last-frame reference voltage and set an initial value of the second low pass filter 9.

Abstract: A wide bandwidth frequency discriminator circuit (200) employs a wide bandwidth limiting amplifier (202) to amplify the IF signal portion of a received RF signal. A frequency-to-voltage circuit 208 is provided having a bandwidth substantially greater than the bandwidth of the IF signal. This discriminator (200) operates to form a detection system capable of discriminating between desired and undesired components of the received RF signal even when said desired and undesired components are nearly identical in amplitude. This is due in part to the enhanced frequency response provided by the discriminator (200).

Abstract: An SSB radio receiver having an inexpensive wide-band IF filter which passes through not only a reception objective SSB station IF signal but also an interference SSB station IF signal simultaneously. These signals are SSB-detected to reproduce the original modulating audio signals with a BFO frequency, the BFO frequency itself located out of the pass-band of the wide-band IF filter. The frequency of the reception objective SSB station IF signal is selected to be nearest to the BFO frequency, preferably at an end of the pass-band width of the IF filter. Frequency spectrums of the SSB-detected audio signals are separated by a frequency difference comprising the difference between the BFO signal and the IF signals. The SSB-detected audio signals are applied to a selected low-pass filter, such as an inexpensive active filter, having a pass-band which covers or passes only the SSB-detected audio signal of the reception objective SSB station IF signal.

Abstract: A double super-heterodyne receiver has a high-frequency input circuit that includes a high-frequency amplifying device, a low-pass filter and a high-pass filter used for obtaining bandpass characteristics for the receiving band. A switching device for changing the cut-off frequency of, at least, the low-pass filter is further provided for the high-frequency input circuit. The switching device is controlled to be on or off in response to the receiving frequency, thereby changing the passband of the high-frequency input circuit. Image disturbance characteristics can thus be improved.

Abstract: A combination of two phase-lock loops, and a cancellation circuit are used to remove a dominant FM signal from within a signal environment. The two phase-lock loops together produce a replica of the highest power (i.e. dominant) FM signal. The cancellation circuit uses this replica in a demodulation, notch-filtering, and remodulation process to excise the dominant FM signal, leaving the other signal(s) undisturbed. Potential applications include co-channel FM signal/interference cancellation and optimizing utilization of RF spectrum.

Abstract: A composite signal recognizer, separator, and FM demodulator apparatus for processing received radio signals. The receiver utilizes N demodulators to process a received signal, where N is equal to or greater than the number of co-channel signals or perceived interference. Detailed in both cross-coupled and cascaded fashion, the receiver first tracks to a predominant (stronger) signal, and regeneratively improves track on other (weaker) signals by subtracting the predominant signal or the predominant noise portion from the input of further demodulation stages.

Abstract: The invention concerns pen-based computers, wherein a pen, or stylus, is positioned on a display of the computer, and produces a signal which allows the computer to detect the position of the stylus. The stylus produces a second signal, which is used as a carrier for telemetry, to transmit data from the stylus to the computer.

Abstract: Method and apparatus for improving an estimate of a message being carried by a frequency modulated dominant carrier in the presence of co-channel interference from a subdominant carrier. An envelope detector provides an envelope signal E(t). A frequency demodulator provides a demodulated frequency signal F(t). In one embodiment, a comparator compares the envelope signal to a threshold voltage V.sub.T. A switch is operated when the envelope signal is less than V.sub.T. The signal F applied to the switch is held by a holding circuit while the switch is open. Interpolation and lowpass filtering improve the quality of the output signal. In another embodiment of the invention, the frequency demodulated signal F is summed with an unfiltered signal to provide a first summed signal. The first summed signal is summed with an unfiltered signal to provide a second summed signal which is an estimate of the message on a co-channel subdominant carrier.

Abstract: This invention provides a method and circuit for separating a signal of interest from an angle modulated interfering signal in which a composite signal, including the signal of interest and the interfering signal, is used to produce first and second signals, the first signal being representative of the composite signal and the second signal being representative of the envelope of the composite signal. Selected components are removed from the second signal to produce a filtered signal. The filtered signal is mixed with the first signal, to produce an output signal including a component representative of the signal of interest having a greater spectral power density than other components of the output signal.

Abstract: A signal receiving system for receiving messages from each of several unequal amplitude FM carriers occupying the same portion of the frequency band. The signal receiving system receives power division multiplexed signals, each of which being allocated a portion of the total average power of an assigned FM band.

Abstract: An FM interference suppressor comprises two FM demodulators, one of which is fed with an input signal via an envelope detector and is arranged to feed a zero frequency detector and a phase inverter to produce a baseband composite signal comprising wanted and unwanted modulation. The other FM demodulator is fed directly with an input signal directly to produce a baseband signal comprising the unwanted modulation alone. A combiner is provided for subtractively combining the baseband signal and the baseband composite signal to produce the wanted modulation signal.

Abstract: A signal receiving system for receiving messages from each of several unequal amplitude FM carriers occupying the same portion of the frequency band.

Abstract: An interference wave detection circuit is designed so as to detect whether a beat due to the difference between two carrier wave frequencies is included or not in a received signal for a radio receiver. The detection circuit comprises circuitry for deriving a first binary signal corresponding to a level of a signal of voice frequency band obtained by demodulating the received signal and for deriving a second binary signal corresponding to a level of an envelope signal of an intermediate frequency signal from the received signal to provide a predetermined time difference between the first and second binary signals.

Abstract: A multipath distortion reducing circuit particularly adapted for use with stereophonic receiving circuits in which the amount of mixing between right and left channels is reduced. In accordance with the invention, the envelope of the received FM signal is AM detected, and the envelope detected circuit is multiplied by the FM detected signal differentiated to provide a distortion cancelling signal. The distortion cancelling signal is summed with the detected FM signal to provide an output having a reduced multipath distortion component.

Abstract: An interference detector for use in determining when two carriers are producing a beat signal, comprising a low frequency automatic gain control amplifier 1' amplifying the received signal, a demodulator 5 and voice detector 6 for determining if the received signal is modulated, an amplitude detector 2 for measuring the amplitude of the amplifier output, a level measuring circuit 3 for measuring the beat component of the amplitude detector output, a comparator 4 for outputting an interference signal when the beat component exceeds a predetermined level, and a gate 7, 8 controlled by the voice detector for inhibiting the interference signal when the received signal is modulated.

Abstract: In a reception system which includes a receiver having a plurality of inter-connected stages and a demodulator, and where there appears at an input of the receiver a desired signal which occupies substantially a predetermined bandwidth, and at least one undesired signal which occupies a bandwidth different from, though partially overlapping the predetermined bandwidth, the improvement includes a signal selector coupled to receiver terminals upstream of the receiver demodulator for normally continuously selecting one of the signals appearing across the receiver terminals, a gain-controlled feedback stage connected with one input thereof to an output of the signal selector for negatively feeding back to the receiver terminals one of the signals substantially 180.degree.

Abstract: The invention eliminates an FM interference from a digital signal when the interference occurs because the FM and digital signals are transmitted over adjacent routes and sharing a common frequency band. An error detector finds a difference between a detected baseband digital signal and an assumed transmission code, which is taken from the baseband signal. The detector produces a first error signal responsive thereto. A phase synchronizing circuit produces an output signal synchronized with the first error signal. A coefficient circuit multiplies the output of the synchronizing circuit by a complex coefficient which is then subtracted from the baseband signal. A second error detector produces a second error signal responsive to the difference between the output of the subtractor and a discriminated transmission code. Responsive thereto to a control circuit varies the complex coefficient to produce an output which is the original baseband signal, free of the FM interference.

Abstract: In a superheterodyne radio receiver, by observing the RF and IF signal levels is detected an occurrence of an interference caused by an interfering strong signal of an adjacent station at a frequency close to that of a desired station signal to be received by the receiver. In case such interference is detected, a cancelling signal is fed to the RF amplifier stage to cancel out this interfering station signal, or the selectivity of the RF amplifier stage is set to be sharper in order to reject the interfering station signal.