Abstract: Techniques and systems for extending the capture range of frequency offset error detection are described. For instance, the present disclose describes efficient frequency estimation structures (e.g., zero crossing minimum/maximum (min/max) structures) that may extend carrier frequency offset error capture range by running a bank (e.g., a set) of parallel capture range structures trialing different frequency errors. In some aspects, a set of frequency offset estimation circuits and a set of correlation circuits (e.g., 1-bit correlators) may be used on parallel streams to perform correlation operations on each branch of a received bit stream to determine correlations with known preamble patterns (e.g., to accurately estimate large frequency offset errors).

Abstract: Certain aspects provide a circuit for frequency conversion. The circuit includes first mixer circuitry coupled to a load circuit and having a first mixer configured to generate a first portion of a frequency-converted differential signal to be provided to the load circuit based on first differential input signals and second differential input signals, and a second mixer configured to generate a second portion of the frequency-converted differential signal based on third differential input signals and fourth differential input signals.

Abstract: Methods, systems, and devices for monitoring a Real Time Clock (RTC) oscillator using Digital Signal Processing (DSP), where a resistance/capacitance (RC) oscillator is configured to output a digital pulse signal and a digital RTC Monitor Integrated Circuit (IC) is configured to monitor the RTC oscillator timing signal using the RC oscillator signal. In one aspect, the RTC Monitor IC includes an RTC input configured to receive the RTC oscillator timing signal; an RC input configured to receive the RC oscillator digital pulse signal; and an RTC reset output configured to output an RTC reset signal when a comparison of the RTC and RC oscillator inputs show the RTC oscillator has missed one or more clock cycles. A single wire input/output for both reset and interrupt signals between circuits is also described.

Abstract: A communication circuit includes a receiver path, a frequency translating loop filter and a signal source circuit. The frequency translating loop filter includes an auxiliary mixer, and a frequency translating filter backend circuit such as a filter. The signal source circuit can be shared with a transmitter path. When the receiver path receives an external signal, the auxiliary mixer and the frequency translating filter backend circuit perform high-frequency filtering. When the receiver path need not receive the external signal, the auxiliary mixer up-converts a low-frequency auxiliary signal provided by the signal source circuit to a high-frequency domain, and the up-converted signal is received by the receiver path. Thus, an operation parameter of the receiver path can be adjusted and calibrated according to a response of the receiver path.

Abstract: A semiconductor device according to the present invention includes a PLL circuit, in which the PLL circuit includes: a phase difference detection unit that detects a phase difference between a reference signal and a division signal; a filter that outputs a control signal according to a detection result of the phase difference detection unit; an oscillation unit that outputs an oscillation signal of a frequency according to the control signal; a division unit that divides the oscillation signal to output it as the division signal; a noise intensity detection unit that detects a noise intensity of a predetermined frequency component included in the control signal; and a phase difference adjustment unit that adjusts a phase difference between the reference signal and the division signal based on the noise intensity detected by the noise intensity detection unit.

Abstract: A distributed antenna system comprises a plurality of antennas and a multi-port hub. The multi-port hub comprises an interface to a telecommunications network and a plurality of transceivers. The multi-port hub is configured to operate in a first mode (“normal” mode) in which the multi-port hub receives a downlink communications signal via the interface and distributes the downlink communications signal to the plurality of antennas using a selected downlink transmission frequency within a downlink frequency range and in which the multi-port hub receives uplink communications signals from the plurality of antennas at a selected uplink receive frequency. The multi-port hub is also configured to operate in a second mode (“listening” mode) in which the multi-port hub receives communications signals from the plurality of antennas at one or more frequencies within the downlink frequency range.

Abstract: An OFDM reception device including: a first orthogonal transformation unit that orthogonally transforms a signal for a useful symbol duration included in an OFDM signal and outputs a resulting orthogonally transformed signal; a second orthogonal transformation unit that orthogonally transforms a signal for a guard interval duration included in the OFDM signal and outputs a resulting orthogonally transformed signal; a detection unit that detects a wide band carrier frequency error amount according to the signal output from the first orthogonal transformation unit and the signal output from the second orthogonal transformation unit; and a correction unit that corrects a wide band carrier frequency shift of the OFDM symbol according to the wide band carrier frequency error amount detected by the detection unit.

Abstract: A method of determining at a receiver whether a received signal comprises a pure tone signal component. The method comprises: measuring a received signal over a measurement period; calculating, using maximum likelihood hypothesis testing, a likelihood ratio value for the measured signal and, determining, based on said likelihood ratio value, whether the measured signal comprises a pure tone signal component. The likelihood ratio value is a value indicative of the ratio of a likelihood LFSC that the measured signal comprises a pure tone signal component, and a likelihood LnoFSC that the measured signal does not comprise the pure tone signal component.

Abstract: Receiver synchronization techniques (RST), contributing more accurate synchronization of receiver clock to OFDM composite frame combined with much faster acquisition time and better stability of the receiver clock, and phase and frequency recovery techniques, comprising a software controlled clock synthesizer (SCCS) for high accuracy phase & frequency synthesis producing synchronized low jitter clock from external time referencing signals or time referencing messages wherein SCCS includes a hybrid PLL (HPLL) enabling 1-50,000 frequency multiplication with very low output jitter independent of reference clock quality.

Abstract: An apparatus comprising an amplifier comprising an input, a capacitor having a capacitor first side and a capacitor second side, wherein the capacitor first side is coupled to the input, a switch having a switch first side and a switch second side, wherein the switch first side is coupled to the capacitor second side, and a transistor having a transistor gate, and a transistor source, wherein the transistor gate is coupled to the input and the capacitor first side, wherein the transistor source is coupled to the switch second side and wherein the switch is positioned directly between the capacitor second side and the transistor source.

Abstract: Modern digital signals include framing. A known sequence of transmission symbols (Unique Word (UW)) included in the transmitted signal may be used by a receiver for framing synchronization. A receiver configured to receive such a signal may be configured to detect the UW even when the signal is received with some frequency uncertainty (e.g. offset or error). A method is presented for fast acquisition of symbol and/or frame timing of a signal, including in the presence of frequency uncertainty. In some embodiments, the presented method may be used for determining a frequency offset of the received signal and a location of a unique word (UW) within a frame of the received signal, wherein said determining is based on a two-dimensional search map.

Abstract: Embodiments include Direct-Conversion Receiver (DCR) apparatus, and methods for performing automatic frequency control based on a received signal. An initial frequency offset value is selected from a lookup table and applied to the receiver's local oscillator. Digital samples are generated based on the received signal, and stored in a buffer in sequential order. A DC estimator performs multiple iterations of a DC component estimation process. The process includes iteratively applying an analysis window to more recently-stored, buffered samples, in order to identify a set of the buffered samples. Within the set of buffered samples, an intermediate value between the amplitudes of two samples is determined (e.g., samples having the largest and smallest amplitudes). Between at least some of the multiple iterations, the number of samples that defines the size of the analysis window is increased.

Abstract: The present invention relates to automatic gain control methods and apparatus for controlling a signal level of a signal at a predetermined location in a signal path of a receiver chain. An automatic gain controller comprises a local signal modifier device for selecting based on an error signal and an oscillator signal from a plurality of alternative oscillator signals, and for providing the selected oscillator signal to a signal mixer located in the receiver chain upstream of said predetermined location for frequency translation of an input signal to said signal mixer.

Abstract: A filter auto-calibration system includes a multi-clock module. The multi-clock module includes a multi-clock generator that is configured to generate a clock signal with a variable frequency based on a channel setting. There is at least one filter to be calibrated. An auto-calibration control module is configured to control calibration of the at least one filter based on the channel setting. The multi-clock module is configured to supply the variable frequency clock signal to the at least one filter and to the auto-calibration control module, and the at least one filter is coupled to the auto-calibration control module.

Abstract: An electronic device which is capable of adjusting the working frequencies of electronic components of a device so as to avoid interference with a received RF signal within a particular range. The electronic device includes a detecting signal and a processor. The detecting unit detects whether a working frequency of an electronic component of the electronic device falls within the predetermined frequency range of the received RF signal. The processor adjusts the working frequency of the electronic component to prevent the received RF signal from being interfered if the working frequency of the electronic component falls with the predetermined frequency range. A method for avoiding RF interference is also provided.

Abstract: Radio frequency (RF) self-tuning amplification devices and methods of amplification for an RF input signal are disclosed. In one embodiment, the RF self-tuning amplification device has a first RF amplifier, a reference RF amplifier, and a tuning circuit. The first RF amplifier includes a first RF amplification circuit to generate an amplified RF output signal from the RF input signal, and a tunable parallel resonator tunable so as to shift an RF output signal phase of the amplified RF output signal. The reference RF amplifier includes a second RF amplification circuit that generates a reference RF signal from the RF input signal, and a resistive load, so that the reference RF signal has a reference RF signal phase. The tuning circuit is configured to tune the tunable parallel resonator to reduce a phase difference between the RF output signal phase and the reference RF signal phase.

Abstract: A radio-frequency (RF) front-end circuit includes a tunable filter, a negative transconductance circuit coupled with the tunable filter to produce a tuning oscillation signal, and a counter arranged to determine a frequency of the tuning oscillation signal. The RF front-end circuit also includes a control circuit arranged to shift the frequency of the tuning oscillation signal by adjusting the tunable filter until the frequency of the tuning oscillation signal falls within an acceptable frequency range corresponding to a desired channel frequency band.

Abstract: A system includes a first clock module, a global positioning system (GPS) module, a phase-locked loop (PLL) module, a cellular transceiver, and a baseband module. The first clock module generates a first clock reference. The GPS module operates in response to the first clock reference. The WLAN module operates in response to the first clock reference. The PLL module generates a second clock reference by performing automatic frequency correction (AFC) on the first clock reference in response to an AFC signal. The cellular transceiver receives radio frequency signals from a wireless medium and generates baseband signals in response to the received radio frequency signals. The baseband module receives the baseband signals, operates in response to a selected one of the first clock reference and the second clock reference, and generates the AFC signal in response to the baseband signals.

Abstract: The present invention discloses a method for implementing automatic frequency control, and an apparatus thereof. The method discloses: calculating a correlation value of common pilot symbols in a reception signal of each path and a frequency offset value, calculating a combined frequency offset value according to the frequency offset value of each path, and determining, according to the combined frequency offset value, a frequency offset adjustment value for a voltage controlled oscillator, a frequency offset adjustment value for overall reception signals and a frequency offset adjustment value for the reception signal of each path. The present invention selects a method of small-scope frequency offset estimation, which makes frequency offset estimation more accurate.

Abstract: An electronic device capable of performing automatic frequency control (AFC) to maintain frequency and timing without good received bursts, in which an oscillation unit and a baseband processing unit are provided. Wherein, the baseband processing unit computes a compensation adjustment according to a prediction model and stored information regarding a previous digital value adjustment when detecting that the baseband processing unit is incapable of controlling the oscillation unit according to received bursts from the remote communication unit, and adjusts the oscillation unit according to the determined compensation adjustment.

Abstract: A method and apparatus is disclosed to process a received single stream communication signal and/or a multiple stream communication. A communications receiver is configured to receive the received communication signal. A communications receiver determines whether the received communication signal includes a single stream communication signal or a multiple stream communication signal. The communications receiver determines whether a received communication signal complies with a known single stream communications standard. The communications receiver determines whether the received communication signal complies with a known multiple stream communications standard. The communications receiver decodes the received communication signal according to the known single stream communications standard upon determining the received communication includes the signal single stream communication signal.

Abstract: A bang-bang frequency detector with no data pattern dependency is provided. In examples, the detector recovers a clock from received data, such as data having a non-return to zero (NRZ) format. A first bang-bang phase detector (BBPD) provides first phase information about a phase difference between a sample clock and the clock embedded in the received data. A second BBPD provides second phase information about a second phase difference between the clock embedded in the received data and a delayed version of the sample clock. A frequency difference between the sample clock and the clock embedded in the received data is determined based on the first and second phase differences. The frequency difference can be used to adjust the frequency of the sample clock. A lock detector can be coupled to a BBPD output to determine if the sample clock is locked to the clock embedded in the received data.

Abstract: Generate a series of digital data according to a pair of differential signals received from a low speed universal serial bus. Calibrate coarsely a frequency of an oscillator according to a width of an end-of-packet of the series of digital data. And calibrate finely the frequency of the oscillator according to a width of a SYNC pattern of the series of digital data.

Abstract: Systems, methods, and other embodiments associated with radio coexistence using clock rate adaptation are described. According to one embodiment, a device includes a system bus configured to transmit and receive data at a clock rate. The device also includes a radio logic configured to receive radio frequency signals. The device further includes a clock logic configured to adjust the clock rate of the system bus when the radio logic is receiving the radio frequency signals.

Abstract: Provided are a receiver and a receiving method for a scalable bandwidth in a mobile station of an Orthogonal Frequency Division Multiplexing (OFDM) system. The receiving method includes the steps of: (a) filtering a received RF signal; (b) oscillating a frequency according to a center frequency control signal to output a local oscillation frequency; (c) down-converting the filtered RF signal by using the local oscillation frequency; (d) scalable-filtering the down-converted signal while adjusting a bandwidth according to a bandwidth control signal; (e) controlling gain of the scalable-filtered signal; (f) converting the gain-controlled analog signal into a digital signal by using a sampling frequency matching with a corresponding bandwidth according to an ADC control signal; and (g) demodulating the converted digital signal, outputting the center frequency control signal, the bandwidth control signal, and the ADC control signal according to control information received from an upper layer.

Abstract: A synthesizer includes a synthesizer unit for generating a local oscillation signal based on a reference oscillation signal output from a reference oscillation unit including a MEMS resonator, a frequency fluctuation detector for detecting a frequency fluctuation of the MEMS resonator, and a frequency adjuster for adjusting a frequency of the local oscillation signal based on the frequency fluctuation detected by the frequency fluctuation detector. This synthesizer can output a signal with a stable frequency, even when an MEMS resonator demonstrating a large fluctuation in an oscillation frequency to temperatures is used.

Abstract: A system includes a first clock module, a global positioning system (GPS) module, a phase-locked loop (PLL) module, a cellular transceiver, and a baseband module. The first clock module generates a first clock reference. The GPS module operates in response to the first clock reference. The WLAN module operates in response to the first clock reference. The PLL module generates a second clock reference by performing automatic frequency correction (AFC) on the first clock reference in response to an AFC signal. The cellular transceiver receives radio frequency signals from a wireless medium and generates baseband signals in response to the received radio frequency signals. The baseband module receives the baseband signals, operates in response to a selected one of the first clock reference and the second clock reference, and generates the AFC signal in response to the baseband signals.

Abstract: A frequency control device receiving a signal transmitted from each of a plurality of mobile stations, the frequency control device includes a first detecting unit to detect a frequency deviation generated from the signal, a second detecting unit to acquire information about at least a current position or movement of each of the mobile stations as classification information, and a classifying unit to classify mobile stations estimated to be moving in a same moving direction with a same moving speed as a first mobile station based on the classification information. The frequency control device includes a first calculating unit to calculate a first frequency deviations of a signal received from the first mobile station, and a compensation unit to compensate the frequency deviation of the signal received from the first mobile station based on the first frequency deviation.

Abstract: A signal processing circuit is provided. The signal processing circuit, adjusting a received radio frequency (RF) signal according to a gain, and generating a digital signal accordingly, the signal processing circuit including a signal analysis circuit, for analyzing the digital signal to generate the gain, determining whether the received RF signal is a target signal, and generating a reference value according to the digital signal, and a baseband circuit, for performing a carrier frequency offset (CFO) compensation to the digital signal according to the reference value, wherein, the reference value is generated while the signal analysis circuit is determining whether the received RF signal is the target signal.

Abstract: Embodiments of a method for tuning the resonant frequency of an antenna in a wireless communication device are disclosed, along with embodiments of a wireless communication device using such a method. Embodiments sense the out-of-band impedance of the antenna, which comprises an antenna element and selectively adjustable impedance disposed between the antenna element and a ground plane of the wireless device, and adjust the selectively adjustable impedance to achieve a desired resonant frequency of the antenna. Embodiments separate an antenna signal into an in-band signal and out-of-band impedance, generate an error signal related to the out-of-band impedance, apply the error signal to a controller circuit configurable to generate an impedance error signal representing the change in antenna impedance, and apply the impedance error signal to the selectively adjustable impedance. Embodiments of a method and electronic circuit for determining the change in impedance of an antenna are also disclosed.

Abstract: A frequency modulation receiver is provided. The frequency modulation receiver includes an automatic frequency controller and a signal detector. The automatic frequency controller receives a demodulated frequency modulation signal demodulated from a radio frequency signal and outputs a control voltage to control an oscillation frequency of a local oscillator. The signal detector coupled to the automatic frequency controller receives the control voltage and determines whether the radio frequency signal is a frequency modulation signal according to the control voltage and a predetermined voltage range.

Abstract: A system and technique for providing to flexible, programmable frequency estimators and spectrum analyzers that can operate over extremely large bandwidths and yet provide high spectral resolution are described. The system and technique may include a cascaded super-heterodyne apparatus for estimating a frequency and a bandwidth of signals proximate in frequency to a desired signal, a tunable filter coupled to an input of a receiver, and a tuner which receives a signal from said cascaded super-heterodyne apparatus and tunes the filter to filter out unwanted signals from the receiver.

Abstract: A receiver having Automatic Frequency Control (“AFC”) is described having at least one input signal terminal and an offset frequency estimation means for estimating each offset frequency of at least two predetermined input signals inputted at the same time at the input signal terminal. The access to the receiver of each input signal is respectively modulated and identified by a distinct code, and in addition an AFC means is included to perform automatic frequency control of a voltage control oscillator serving as a frequency reference of the receiver. The AFC means described in the present invention is operative to provide a unique compensation command defined as a function of a combination of at least two analytical terms, each term respectively depending on the estimated offset frequency of the corresponding input signal.

Abstract: A method to track and control the resonance frequency of a band-pass filter provides a solution for the sensitivity limitations against temperature and process variations. A phase sensing module obtains the phase difference between the input and output and a negative feed-back control architecture can be used to tune the filter's resonance over the input RF frequency.

Abstract: A method for tuning an oscillator frequency produced in a radio-receiver chain is based on a slope analysis of a residual difference between the oscillator frequency and a carrier frequency of a radio-received signal. Depending on the slope value calculated, a bandwidth of a low-pass time-filtering that is effective for the frequency difference is increased or set back to a default value. The method provides an improved trade-off between tuning precision and dynamic behavior when the frequency difference drifts rapidly.

Abstract: A method and system of fine timing synchronization for an OFDM signal. The OFDM signal is coarse timing synchronized, generating a synchronization sequence and a CFR (Channel Frequency Response). The synchronization sequence is removed. A correlation coefficient of the correlation between the CFR applied to a number of carriers and the number of carriers with different window shifts is calculated. The largest window shift corresponding to a downsampling factor is indicated by the lowest correlation coefficient greater than a threshold. The CFR is downsampled by the downsampling factor, and an inverse FFT is performed on the downsampled CFR with a reduced number of calculations reduced by the downsampling factor, transforming the CFR into a CIR. A fine timing synchronization position is determined from the CIR and is utilized by an FFT unit within an OFDM receiver to accurately receive OFDM symbols of the OFDM signal.

Abstract: Provided is an apparatus for estimating a frequency offset by one training symbol including two symbols having the same structure and value in an OFDM system. The apparatus includes a first likelihood function calculator for modeling non-Gaussian impulsive noise included in the training symbol to a Cauchy probability density function in which a characteristic exponent of a BIS?S probability density function is 1, and calculating a likelihood function of a Cauchy distribution using the Cauchy probability density function, and a first frequency offset estimator for estimating an effective frequency offset value in which the likelihood function of the Cauchy distribution of the first likelihood function calculator becomes highest as a frequency offset estimation value. Thereby, it is possible to improve the performance of frequency offset estimation in non-Gaussian impulsive noise environments.

Abstract: A radio wave receiver including an antenna for receiving a radio wave; a tuning unit that can discretely changing a frequency characteristic of the antenna; an oscillation generator that can oscillate the antenna and a circuit portion of the tuning unit; a reception processing section for extracting a signal of a desired wave out of a reception signal received from the antenna; a controller for generating an oscillation signal at the circuit portion by the oscillation generator, and switching a setting of the tuning unit to search a setting state of the tuning unit under which the oscillation signal is extracted by the reception processing section; and a compensator for applying a variation to a frequency characteristic of the oscillation signal or a frequency characteristic associated with signal extraction of the reception processing section when the controller searches the setting state.

Abstract: Computer implemented methods and systems for the prediction of the reception of a desired in-band on-channel digital audio broadcast signal (IBOC DAB) are described. A method includes computing a first ratio of a weaker undesired adjacent broadcast signal to a stronger undesired adjacent broadcast signal; computing a second ratio of the desired IBOC DAB signal to the stronger undesired adjacent roadcast signal. The method also includes computing a minimum allowable reception ratio based on the second ratio and the slope and intercept of a line, wherein the slope and intercept of the line is based on both (i) a plurality of ratios of a weaker adjacent broadcast signal to a stronger adjacent broadcast signal and (ii) a plurality of ratios of a desired IBOC DAB signal to a stronger adjacent broadcast signal. Reception is predicted when the computed minimum allowable reception ratio is less than the first ratio.

Abstract: A mobile station (14) transmits a signal after connection is established, by using the same number of subcarriers as the number of subcarriers equal to or smaller than a predetermined number used for transmitting a connection request signal (TCCH). A base station (12) detects the number of subcarriers used for transmitting the connection request signal (TCCH) (S106), and controls in accordance with the detected number of subcarriers the passband width of a bandpass filter having a passband with a variable width accommodating the predetected number of subcarriers, for separating a signal of the mobile station (14) falling within the passband from a received signal (S108).

Abstract: Provided are a receiver and a receiving method for a scalable bandwidth in a mobile station of an Orthogonal Frequency Division Multiplexing (OFDM) system. The receiving method includes the steps of: (a) filtering a received RF signal; (b) oscillating a frequency according to a center frequency control signal to output a local oscillation frequency; (c) down-converting the filtered RF signal by using the local oscillation frequency; (d) scalable-filtering the down-converted signal while adjusting a bandwidth according to a bandwidth control signal; (e) controlling gain of the scalable-filtered signal; (f) converting the gain-controlled analog signal into a digital signal by using a sampling frequency matching with a corresponding bandwidth according to an ADC control signal; and (g) demodulating the converted digital signal, outputting the center frequency control signal, the bandwidth control signal, and the ADC control signal according to control information received from an upper layer.

Abstract: A transmitter and a signal amplifier are provided. The signal amplifier includes a digital-to-analog converter converting an input digital signal into an analog signal, a local oscillator signal generator outputting in-phase and quadrature-phase oscillator signals, a first mixer mixing the analog signal with the in-phase local oscillator signal to output an in-phase high frequency signal, a second mixer mixing the analog signal with the quadrature-phase local oscillator signal to output a quadrature-phase high frequency signal, a main amplifier amplifying the in-phase high frequency signal output from the first mixer, and an auxiliary amplifier amplifying the quadrature-phase high frequency signal output from the second mixer.

Abstract: A frequency tunable filter is disclosed. The disclosed filter comprises a filter unit having a sliding member so as to be capable of tuning a frequency band of a frequency signal being filtered; a communication module configured to receive a control signal for controlling the tuning of the frequency band; and a control unit configured to control the tuning of the frequency band by moving the sliding member based on the control signal. With the disclosed filter, the tuning of the filter may be performed automatically by way of control signals transmitted from a remote location.

Abstract: A system comprises a first clock module configured to generate a first clock reference that is not corrected using automatic frequency correction (AFC). A global position system (GPS) module is configured to receive the first clock reference. An integrated circuit for a cellular transceiver includes a system phase lock loop configured to receive the first clock reference, to perform AFC, and to generate a second clock reference that is AFC corrected.

Abstract: Certain embodiments of the present disclosure provide a method for frequency-domain gain control in system utilizing orthogonal frequency division multiplexing (OFDM) multiple input multiple output (MIMO). The proposed method reduces the complexity of the system while maximizing the internal accuracy of the OFDM MIMO decoder and preserving the performance of the system.

Abstract: A method and an apparatus for switching from the main frequency to an Alternative Frequency (AF) providing the same station is provided. The method includes measuring a received signal strength of a main frequency, receiving at least one alternative frequency list, establishing an accumulated alternative frequency list including all previously received alternative frequency lists, comparing the received signal strength of the main frequency with a predefined reference received signal strength, and attempting, when the received signal strength of the main frequency is less than the reference received signal strength, switching to an alternative frequency in the accumulated alternative frequency list.

Abstract: Systems and methods for tuning an antenna for a frequency modulation (FM) transceiver are provided. A representative system includes: a network of electrical adjustable passive components that receives and sends radio frequency (RF) signals to a receiver circuitry via the network of electrical adjustable passive components. The receiver circuitry determines the received signal strength indication (RSSI) of the RF signal. The system further includes a transmitter circuitry that transmits RF signals via the network of electrical adjustable passive components, and a peak detector circuitry that receives and determines a voltage output of the RF signals from the variable capacitors. An auto-tune circuitry receives the RSSI and output value from the receiver circuitry and the peak detector circuitry, respectively.

Abstract: According to one aspect of the present invention, an apparatus is provided to enable weather band radio signals to be received and processed using a digital signal processor (DSP). The DSP can include functionality to implement both frequency modulation (FM) demodulation and weather band data demodulation, i.e., specific area encoding (SAME) demodulation. In one such embodiment, soft decision samples of a SAME message can be combined, and based on a combined result, a hard decision unit can generate a bit value of weather band data.

Abstract: There is provided a frequency control device that includes a frequency synchronizer to transform a radio signal to a baseband signal, a same signal correlator to obtain a first correlation value between a first signal in a first position in a first transmission symbol of the baseband signal and a second signal included in a second period, a different symbol correlator to obtain a second correlation value between a third signal included in a third period of the first transmission symbol and a fourth signal included in a fourth period, a frequency error estimator to estimate a frequency error added on the radio signal based on a phase rotation value of a difference value obtained by a subtraction of the second correlation value from the first correlation value, and a frequency corrector to correct the baseband signal to cancel the frequency error.

Abstract: A receiving apparatus includes a first circuit to receive a radio wave of a first frequency band from a tuning circuit, a second circuit, including an amplifier to receive a radio wave of a second frequency band lower in frequency than the first frequency band, and a generating circuit to generate a tuning voltage for the tuning circuit in a first state in which the radio wave of the first frequency band is received, and a bias voltage for the amplifier in a second state in which the radio wave of the second frequency band is received. The generating circuit includes a voltage generator to generate and output the tuning voltage and the bias voltage to an output route, and a switching circuit to switch the output route to couple to the amplifier in the second state.