Abstract: The present invention relates to a method for receiving a paging signal in a wireless communication system, and a device therefor, the method comprising the steps of: determining index information indicating a wake up signal (WUS) resource; and monitoring a WUS on the basis of the determined index information, wherein, when a user equipment (UE) supports machine type communication (MTC), the index information indicating the WUS resource is determined on the basis of identification information of the UE, parameters related to a discontinuous reception (DRX) cycle of the UE, information related to the number of paging narrowbands, and information related to the number of UE groups for the WUS.

Abstract: The present invention relates to a method for receiving a paging signal in a wireless communication system, and a device therefor, the method comprising the steps of: determining index information indicating a wake up signal (WUS) resource; and monitoring a WUS on the basis of the determined index information, wherein, when a user equipment (UE) supports machine type communication (MTC), the index information indicating the WUS resource is determined on the basis of identification information of the UE, parameters related to a discontinuous reception (DRX) cycle of the UE, information related to the number of paging narrowbands, and information related to the number of UE groups for the WUS.

Abstract: An assessment tool for assessing signaling ingress and small cell placement within a communication network is contemplated. The assessment tool may include capability sufficient for assessing signaling ingress associated with radio frequency (RF) signaling attenuating, influencing or otherwise interfering with other signaling being transmitted over a communication network.

Abstract: Certain aspects of the present disclosure provide techniques for beam management for make-before-break (MBB) handover. A method that may be performed by a user equipment (UE) includes establishing a first cell connection with a first base station (BS) while maintaining an existing second cell connection with a second BS, and determining that a first transmission time of a first signal transmitted by the first BS is less than a threshold time duration from a second transmission time of a second signal transmitted by the second BS. In some examples, the first signal is associated with one or more first communication metrics and the second signal is associated with one or more second communication metrics, wherein each of the one or more first communication metrics and the one or more second communication metrics comprise one or more quality of service (QoS) metrics.

Abstract: An electronic device and method are disclosed. The device includes: first wireless communication circuitry for a 5G network, second wireless communication circuitry for a 4G network or a WiFi network, at least one processor. The processor implements the method, including: establishing a video call with an external electronic device on the 4G network or the WiFi network, identify a resolution of the video call, setting a reference value for executing a first handover to the 5G network to be less than a default value, maintain the reference value, when the identified resolution is less than the predetermined threshold resolution, and perform the first handover from the 4G network or the WiFi network to the 5G network, when a RSSI intensity of a signal from the 5G network.

Abstract: The present invention relates to a method for receiving a paging signal in a wireless communication system, and a device therefor, the method comprising the steps of: determining index information indicating a wake up signal (WUS) resource; and monitoring a WUS on the basis of the determined index information, wherein, when a user equipment (UE) supports machine type communication (MTC), the index information indicating the WUS resource is determined on the basis of identification information of the UE, parameters related to a discontinuous reception (DRX) cycle of the UE, information related to the number of paging narrowbands, and information related to the number of UE groups for the WUS.

Abstract: A unidirectional sampling mixer utilizes a stepped phase modulation to shift the frequency of an input signal. An RF input signal is supplied to an RF input switch from an RF input port. An ordered set of phase shift values to be applied to the RF input signal and a set of times each element of which correspond to a time at which a phase shift value is be applied to the RF signal are determined. For each phase shift value within the ordered set of phase shift values, a controller controls the RF input switch to select an input of a phase shifting device and controls an RF output switch to select an output of the phasing shifting device. The input of the phase shifting device and the output of the phase shifting device are selected to apply the phase shift value at its corresponding time to the RF input signal. A frequency shifted signal is supplied to an RF output port from an output of the RF output switch.

Abstract: A radio frequency receiver subject to a large in-band interferor employs active cancellation with coarse and at least one cancellation signals, each with a respective radio frequency combiner, in order to increase the effective dynamic range of the receiver for weak signals of interest. One or both can be digitally synthesized. This is particularly applicable for co-site interference, whereby the interfering transmit signal is directly accessible. A similar system and method may also be applied to external interferors such as those produced by deliberate or unintentional jamming signals, or by strong multipath signals. An adaptive algorithm may be used for dynamic delay and gain matching. In a preferred embodiment, a hybrid technology hybrid temperature system incorporates both superconducting and semiconducting components to achieve enhanced broadband performance.

Abstract: An integrated circuit comprising processing logic for operably coupling to radio frequency (RF) receiver circuitry arranged to receive a wireless network signal. The receiver circuitry generates in-phase and quadrature digital baseband representations of the wireless network signal. The processing logic determines quadrature (I/Q) imbalance of the RF receiver circuitry based on the in-phase and quadrature digital baseband representations of the wireless network signal.

Abstract: A noise level of an output signal is maintained low. An adjacent interference detecting unit compares a signal level of a wide band signal which is a desired station signal of a relatively wide band and a signal level of a narrow band signal which is a desired station signal of a relatively narrow band, and judges that adjacent interference has occurred when the signal level of the narrow band signal is less than or equal to a predetermined level even though the signal level of the wide band signal is greater than or equal to a predetermined level. A variable amplifier (36) attenuates an L?R signal and forms a monophonic signal when the signal level of the narrow band signal is lower than a predetermined level. With this process, when there is adjacent interference, a signal level of the narrow band signal at which the attenuating unit starts attenuating the L?R signal is changed to a relatively high value.

Abstract: A method is performed for a signal transmitted by an RFID interrogator being a radiofrequency electromagnetic sine wave. An amplitude noise contribution RSdAN to a demodulated received signal RSd within a frequency interval of a low-pass filter is determined by means of a measured demodulated transmitted signal TSd as RSdAN=k·TSd in that a dc component DCRS in said demodulated received signal RSd and a dc component DCTS in said demodulated transmitted signal TSd are measured and a conversion factor k is determined as k=DCRS:DCTS. A receiver output signal O is continuously generated out of the received signal by subtracting said amplitude noise contribution RSdAN from the demodulated received signal RSd, filtering the cleaned signal RSd-k.TSd by the low-pass filter and amplifying it. The conversion factor is determined in an exceptionally simplified way as said ratio of said dc components. No receiving interruptions are needed.

Abstract: Device for compensating a DC component inherent in any radio frequency chain in which from a single measurement, generally obtained from a digital stage, a set of multiple compensation values is determined by a compensation value vector generating module and which compensation values are applied to multiple compensation points of the analog chain. The compensation values are calculated by an iterative process converging toward cancellation of the DC component and avoid saturating amplification components and components of the analog-to-digital converter. The module includes compensation value calculation units each configured to calculate a respective compensation value and provide the calculated compensation value to the respective compensation point.

Abstract: A unidirectional sampling mixer utilizes a stepped phase modulation to shift the frequency of an RF input signal supplied to an RF input switch. An ordered set of phase shift values to be applied to the RF input signal and a set of times each element of which corresponds to a time at which a phase shift value is be applied to the RF signal are determined. For each phase shift value, a controller controls the RF input switch to select an input of a phase shifting device and controls an RF output switch to select an output of the phasing shifting device. The input and the output of the phase shifting device are selected to apply the phase shift value at its corresponding time to the RF input signal. A frequency shifted signal is supplied to an RF output port from an output of the RF output switch.

Abstract: A radio frequency (RF) receiver includes an amplifier stage, a blocking module, and a down conversion module. The amplifier stage amplifies an inbound RF signal (includes a desired component and a blocking component) to produce an amplified inbound RF signal. The blocking module generates an oscillation corresponding to a frequency of the blocking component and filters the amplified inbound RF signal based on the oscillation to substantially attenuate the blocking component and to pass, substantially unattenuated, the desired component. The down conversion module converts the desired RF signal component into a baseband or near baseband inbound signal.

Abstract: A high temperature communications circuit includes a power conductor for concurrently conducting electrical energy for powering circuit components and transmitting a modulated data signal, and a demodulator for demodulating the data signal and generating a serial bit stream based on the data signal. The demodulator includes an absolute value amplifier for conditionally inverting or conditionally passing a signal applied to the absolute value amplifier. The absolute value amplifier utilizes no diodes to control the conditional inversion or passing of the signal applied to the absolute value amplifier.

Abstract: Systems and methods are provided for adjusting a noise figure in a radio receiver. An example method includes receiving a radio frequency (RF) signal at a RF receiver section. The RF receiver section includes at least one RF receiver element. The RF receiver element is controllable by at least one tuning variable. The RF signal is processed to generate a processed analog signal, which is converted to a digital signal. The digital signal is used to determine a performance parameter. The at least one tuning variable of the at least one RF receiver element is controlled to adjust the noise figure based on the performance parameter. In another aspect of the invention, an example radio receiver is provided. The radio receiver includes a RF receiver section having at least one RF receiver element. A controller determines a performance parameter using the digital signal and controls the at least one tuning variable to adjust the noise figure based on the performance parameter.

Abstract: A very low intermediate frequency (VLIF) receiver comprising a first and second mixer circuits, characterised in that receiver comprises a means of estimating the energy in a desired signal band; a means of estimating the energy in a band of frequencies comprising the desired signal band; and a means of altering a VLIF of the receiver according to the ratio of the energy in a desired signal band and the energy in the band of frequencies comprising the desired signal band.

Abstract: It is an object of the present invention to provide a mobile station which enables transmission of control information on broadcast communication or multicast communication to a radio network controller without establishing a dedicated channel in broadcast communication or multicast communication. The mobile station related to this invention includes a control information generating unit (14) for generating control information on broadcast communication or multicast communication, a control information identifier adding unit (15, 16, 17) for adding a control information identifier for specifying a type of the control information to the control information, and a transmitting unit (12) for transmitting the control information to a radio network controller (RNC) via a common channel.

Abstract: An RF sensing circuit with a voltage-controlled oscillator comprises a low noise amplifier (LNA), a voltage-controlled oscillator (VCO), a frequency demodulating unit, a bandpass filter (BPF) and a digital signal processing unit. The VCO has an injection signal input port and a voltage input port, wherein the injection signal input port is electrically connected with an output of the LNA. The frequency demodulating unit is electrically connected with an output of the VCO and the BPF is electrically connected with an output of the frequency demodulating unit. The digital signal processing unit is electrically connected with an output of the BPF and the voltage input port of the VCO.

Abstract: A system and method for improving the processing of communications signals received in the presence of narrowband interference signals. The received communications signals are time sampled and transformed into a series of spectral terms in the frequency domain that are then evaluated to identify narrowband interference signals. The identified narrowband interference terms can be calculated to a value that will optimize the corrupted spectral terms resulting from the communication, and an inverse transformation can be used to generate a time domain signal that is free from interference.

Abstract: The component, fully integrated onto a monolithic substrate, includes a tuner, a demodulator, and a channel decoder. The overall filtering is carried out in two parts, a baseband analog filtering and a digital Nyquist filtering removing the information of adjacent channels. It outputs a stream of MPEG data.

Abstract: An audio comparison method and apparatus compares audio streams by measuring the times of volume peaks in the audio streams and identifying correlations between the peaks in the audio streams, subject to possible delay between the streams. The audio comparison allows the identification of audio streams including the same audio content even in the presence of delay and distortion and using low processing power. The audio comparison has particular application in car radios to allow automatic retuning.

Abstract: A method and apparatus for receiving and playing a signal in a radio receiver to suppress microphonic feedback are provided by alternately pitch shifting a received audio signal. The pitch of the received audio signal is alternately shifted up and then down, repeatedly over successive intervals of the audio signal, to produce a pitch swing signal which is then played over a speaker. The alternating pitch shifting prevents the buildup of regenerative feedback normally caused by acoustic vibrations coupling into the radio receiver.

Abstract: Disclosed is an inter-cell interference mitigation method using a spatial covariance matrix (SCM) estimation method in a multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) communication system for mitigating interference between asynchronous cells. The inter-cell interference mitigation method includes extracting a reference symbol (RS) of a received OFDM symbol and performing channel estimation, estimating an initial SCM using the RS signal and the channel estimation result, applying time-domain sinc type weighting to the initial SCM and applying an SCM, and demodulating a data symbol with mitigated inter-cell interference using the channel estimation result and the estimated SCM.

Abstract: In one embodiment, a method for processing radio frequency signals includes estimating an average value of a demodulated signal and a noise signal, both obtained from a radio frequency signal, estimating a noise floor based on the noise signal, generating a blend control signal based on the average values and the noise floor, and blending at least two path signals based on the blend control signal to obtain a blended signal. This blended signal may be output for further processing when multipath noise is detected.

Abstract: A method for demodulating an RF input signal using an envelope detector and synchronous switching of the input signal before entering and after leaving the envelope detector, the envelope detector having a non-linear transfer function acting essentially as a squaring function. The invention also relates to an electronic receiver circuit performing such a method, and to an RF receiver comprising such an electronic receiver, and to an electronic device comprising such an RF receiver, and to the use of such an RF receiver as a wake-up receiver.

Abstract: A method for compensating a transceiver for impairments includes transmitting a plurality of partial bandwidth training signals using a transmitter. A plurality of response signals of a receiver having a bandwidth and exhibiting receiver impairments is captured. Each response signal is associated with one of the partial bandwidth training signals. Each of the partial bandwidth training signals is associated with a portion of the receiver bandwidth. A plurality of partial compensation filters is generated based on the plurality of response signals. Each partial compensation filter is associated with one of the response signals. The partial compensation filters are combined to configure a receiver compensation filter operable to compensate for the receiver impairments.

Abstract: Systems and methods for bundling signals in a wireless communication system are disclosed. A connection request and a reservation for QoS resources can be bundled into an access message at an access terminal. The access message with the bundled communication signals can then be transmitted to an access network. An application layer (e.g., a DataOverSignaling (DOS)) message can also be bundled with the connection request and the reservation into the access message.

Abstract: A device and method for DC offset cancellation device are disclosed. The method includes keeping a high pass module at off state, converting an analog radio frequency signal to a digital baseband signal by a direct down conversion receiving module, detecting a DC offset value during the conversion by an offset compensation module so as to provide an offset compensation signal corresponding to the DC offset value to the direct down conversion receiving module, and determining whether a control condition is reached by a control module so as to timely switch on the high pass module for canceling the residual DC offset in the direct down conversion receiving module. In the present invention, the offset compensation module provides preliminary offset compensation signals and then the high pass module accurately cancels residual DC offset, thereby significantly reducing the reaction time for DC offset cancellation.

Abstract: An apparatus for reducing audio clicks in frequency modulated radio system includes a receiver for receiving a frequency modulated (FM) signal, and a processor for demodulating the received signal and estimating a frequency error, wherein the processor is configured to determine phase variations of the received FM signal by comparing a phase of a first signal sample to a phase of a second signal sample, wherein the first signal sample and the second signal sample are separated in time by more than one sample.

Abstract: In accordance with one aspect of the disclosure, apparatus are provided. A filter is provided to receive from an antenna a receive signal of a given type and a low noise amplifier is provided to amplify the received signal. A translator down translates the receive signal carried at a radio frequency to be carried at an intermediate frequency. An I/Q channel separator is provided to separate the receive signal carried at the intermediate frequency into an analog in-phase (I) signal in an I channel and an analog quadrature-phase (Q) in a Q channel. An analog-to-digital (A/D) converter is provided to respectively convert the I signal and the Q signal to digital domain representations of the I signal and the Q signal. An intermodulation (IM) distortion avoider is provided to avoid IM distortion in the receive signal. The IM distortion avoider includes a carrier frequency exchanger to exchange an IM carrier frequency of IM distortion contained in the receive signal with a carrier frequency of the receive signal.

Abstract: A receiving system for audio processing includes a first demodulation unit and a second demodulation unit. The first demodulation unit is utilized for receiving an audio signal and generating a first demodulated audio signal. The second demodulation unit is utilized for selectively receiving the audio signal or the first demodulated audio signal according to a setting of a television audio system which the receiving system is applied, and generating a second demodulated audio signal.

Abstract: A passive processing device (D) is adapted to be interfaced in a full integrated way on at least a first audio signal path defined between a first audio signal source and an audio signal processing means of an electronic device, such as a mobile communication device. This device (D) comprises a first protection means (DE11; DE12) for rejecting electrostatic discharges on the first path, a first rejection means (CR11, R11; CR12) for rejecting radio signals at least in a chosen frequency band on the first path, and a first AC-coupling means (CC1) for interfacing voltage levels between the first audio signal source and the audio signal processing means.

Abstract: Low-power wireless receivers and low-power communication methods and systems are provided. According to some embodiments, a low-power wireless receiver can comprise an input module, a controller, and a feedback loop. The input module can receive a wireless signal from a wireless communication channel. The controller can receive the wireless signal and provide a control signal corresponding to the wireless communication channel. The controller can be operatively configured to dynamically modify the control signal responsive to conditions of the wireless signal and/or the communication channel. The feedback loop can be disposed between the controller and the input module and can dynamically provide the control signal to the input module such that the input module can modify quality conditions of the wireless signal.

Abstract: Techniques for cancelling DC offset are described. A DC offset cancellation circuit in a receiver cancels DC offsets caused by leaked LO (local oscillator) signals from a LO signal generator. The receiver first calibrates itself by using the DC offset cancellation circuit during a transmit mode. During the calibration, the DC offset cancellation circuit stores the DC offset voltage signal caused by the leaked LO signals. During a receiving mode when the receiver is receiving a signal, the receiver subtracts the stored DC offset voltage signal from the received signal to cancel the DC offsets caused by leaked LO signals.

Abstract: A filter circuit that removes high-frequency components from an input signal, comprises: an operational amplifier; a first resistor connected between a non-inverting input terminal of the operational amplifier and an input signal source; a first capacitor connected to the non-inverting input terminal of the operational amplifier; a second resistor connected to the non-inverting input terminal of the operational amplifier; a third resistor connected between an inverting input terminal of the operational amplifier and the input signal source; a second capacitor connected between the inverting input terminal of the operational amplifier and an output terminal of the operational amplifier; and a fourth resistor connected to the inverting input terminal of the operational amplifier.

Abstract: A digital demodulation device for demodulating an amplitude modulation (AM) signal whose carrier has a first frequency includes: a processing circuit for performing first path digital processing and second path digital processing according to a second frequency and digital values of the AM signal, where the first path digital processing represents performing down conversion by mixing the AM signal with a first sinusoidal signal whose frequency is equal to the second frequency, the second path digital processing represents performing down conversion by mixing the AM signal with a second sinusoidal signal whose frequency is equal to the second frequency, the second frequency is equal to the first frequency plus a predetermined frequency shift, and the second sinusoidal signal is orthogonal to the first sinusoidal signal; and an output stage for outputting an output signal according to processing results of the first path digital processing and the second path digital processing.

Abstract: A method for demodulating an RF input signal using an envelope detector and synchronous switching of the input signal before entering and after leaving the envelope detector, the envelope detector having a non-linear transfer function acting essentially as a squaring function. The invention also relates to an electronic receiver circuit performing such a method, and to an RF receiver comprising such an electronic receiver, and to an electronic device comprising such an RF receiver, and to the use of such an RF receiver as a wake-up receiver.

Abstract: Disclosed is a method for receiving a signal by a receiver in a communication system, the method includes receiving a signal; estimating a first noise value by using a reference signal included in the received signal; estimating a second noise value by using at least one subcarrier which has been unused for a transmission of data and the reference signal; and when a difference between the estimated first noise value and the estimated second noise value is greater than a threshold value, demodulating the data by using an interference removal algorithm.

Abstract: A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.

Abstract: An apparatus included a receiver for receiving an audio file signal, a decoder for demodulating the audio file signal; and a processor for polling the decoder for a loss of a phase lock in the demodulating of the audio file signal. The processor resets and reinitializes the decoder in response to the loss in the phase lock loop. The receiver includes 90 MHz radio frequency reception circuit. The decoder comprises an eight-to-four modulation EFM decoder. In the preferred embodiment, the decoder outputs a digital audio stream that conforms to a known I2S audio stream format.

Abstract: In a direct conversion receiver, to cancel a DC offset generated in the baseband processing block, negative feedback arrangements comprising a gain control amplifier and a low-pass filter are respectively attached to the I and Q signal branches of the baseband block following mixer outputs. The gain control amplifier in each negative feedback circuit is gain adjusted so that the product G·B of the gain G of a primary gain control amplifier and its own gain B will be constant and thereby the DC offset is cancelled. This DC offset cancellation can be applied in a continuous receiving system with no intermittent time during a receiving operation. Capacitance elements located off-chip can be reduced to those to be used only in the low-pass filters in the negative feedback circuits, whereas many off-chip capacitance elements have been required to be inserted between each stage of gain control amplifiers in conventional baseband chains.

Abstract: A method for adjusting the volume and frequency response for the audio output in a mobile communication device comprises estimating the noise level of the environment surrounding the mobile communication device and then adjusting the volume and frequency response based on the estimated noise level.

Abstract: Disclosed is a method for receiving DMB services with a DMB receiving apparatus capable of operating both in first DMB receiving mode and in second DMB receiving mode in a weak electromagnetic field region. The method includes setting the DMB receiving apparatus to the first DMB receiving mode both to receive first DMB packet data and to detect second DMB packet data, checking detection of the second DMB packet data if an event occurs preventing reception of the first DMB packet data during the first DMB receiving mode, notifying the user of the DMB receiving apparatus of possibility of switching the apparatus from the first to the second DMB receiving mode if the second DMB packet data is detected, and switching the DMB receiving apparatus from the first to the second DMB receiving mode according to a user switching request.

Abstract: Methods (1500) and corresponding systems (400, 500) for determining and correcting a DC offset in a receiver operate to sample (1503) a signal to provide complex samples; estimate (1505) a Direct Current (DC) offset corresponding to each of the complex samples, the estimating the DC offset further including solving a plurality of equations relating to the plurality of complex samples, e.g., N simultaneous equations in N samples with a power of the signal invariant across the N samples, to deterministically derive offset values; and then remove (1517) the DC offset from the signal.

Abstract: A radio frequency receiver 30, 32, includes a first component block 12, 16, 18, 20; a second compensating component block 22, 22a-22b, 34; and control circuitry 26 operable for controlling the state (e.g., load, bias, gain) of the first component block. When the control circuitry 26 causes a change in the state of the first component block that is expected to induce a DC offset in a signal, the control circuitry 26 changes the state of the second component block to compensate for an estimate of the DC offset. Preferably, the second component block is a filter 22, 22a-22b, 34, that temporarily changes from a nominal cutoff frequency to an elevated cutoff frequency so that voltage will settle quickly and accurately at an estimated voltage, the estimated voltage being predetermined and based on the state change to the first component block. A method is also described for practicing the invention.

Abstract: A method of removing noise and interference from a signal by receiving the signal, calculating a joint time-frequency domain of the signal, estimating instantaneous frequencies of the joint time-frequency domain, modifying each estimated instantaneous frequency, if necessary, to correspond to a frequency of the joint time-frequency domain to which it most closely compares, redistributing the elements within the joint time-frequency domain according to the estimated instantaneous frequencies as modified, computing a magnitude for each element in the joint time-frequency domain as redistributed, plotting the results as the time-frequency representation of the signal, identifying in the plot any noise and interference components in the received signal, eliminating from the redistributed joint time-frequency domain elements that correspond to noise and interference, and recovering a signal devoid of noise and interference from the modified redistributed joint time-frequency domain.

Abstract: An AM receiving circuit is disclosed which comprises an intermediate frequency amplifying unit that generates an intermediate frequency signal from a broadcast wave signal received by an antenna to amplify and output the intermediate frequency signal; an AGC (Automatic Gain Control) unit that sets gain of the intermediate frequency amplifying unit depending on electric field intensity of the broadcast wave signal; and an AM detecting unit that detects the intermediate frequency signal output from the intermediate frequency amplifying unit, wherein the AM receiving circuit comprises a sound quality compensating unit including: a filter unit that extracts a predetermined frequency band of the audio signal; an amplifying unit that boosts or attenuates the audio signal in the predetermined frequency band extracted from the filter unit; and a controlling unit that controls filter characteristics of the filter unit and sets a boosting function or an attenuating function of the amplifying unit, depending on the elec

Abstract: Certain embodiments of the present invention provides a system and method for SAP FM demodulation. The system includes a bandpass filter for isolating the SAP signal, a Hilbert filter to produce a copy of the SAP signal phase shifted by 90 degrees, an FM demodulator for demodulating the SAP signal using the phase shifted SAP signal and a delayed SAP signal, and a lowpass filter to eliminate noise from the FM demodulated SAP signal. The system may also include an automatic gain control for normalizing amplitude of FM demodulator input signals. The digital FM demodulator uses a simplified approximation using non-unity delay for simplified demodulation of frequency modulated signals.

Abstract: In a radio apparatus, the band of a loop filter of a synthesizer in a blank channel searching state is narrower than the band in a communicating state. In addition, a radio wave environment is measured. A characteristic necessary for the radio apparatus is determined corresponding to the measured-radio wave environment. The power is controlled corresponding to the performance of the radio apparatus. Thus, the power consumption is decreased. In addition, the efficiency of the output power is improved. In the radio apparatus, the current consumption of a power amplifier PA is measured. A matching circuit (LNA or MIX) of the antenna is adjusted with the measured result so as to decrease an antenna loss. In the radio apparatus, a DC offset is removed from the transmitted power and the reflected wave. When the DC offset is removed using an AC coupling capacitor, the deterioration of the frequency characteristic of the receiving portion is compensated with a capacitor in a digital signal process.