Abstract: One embodiment of the present invention provides a receiver for wireless communication. The receiver includes a demodulator and at least one filtering mechanism coupled to the demodulator, and an analog-to-digital converter (ADC) coupled to the filtering mechanism. The filtering mechanism can be configured to function as a low-pass filter (LPF) or a band-pass filter (BPF), thereby enabling the receiver to function as a direct-conversion receiver or a low-intermediate frequency (low-IF) receiver.

Abstract: A wide/narrow-band RF transceiver receives a signal in wide-band RF spectrum; a processor analyzes the signal and narrows the bandwidth of the RF transceiver in accordance with a carrier frequency, bandwidth, and RF modulation type of the signal.

Abstract: A broad band packet radio communication system is characterized by the carrier sense multiplexing connection method operated on a harsh frequency arrangement where an occupied band width of a modulation transmission/reception wave and a modulation side lobe are wide and the frequency channel interval is narrow. It is possible to improve the reception adjacent channel interference characteristic among a plurality of terminals belonging to the respective cells existing in the vicinity of adjacent frequency cell boundary area. The RSSI system is subjected to a narrow-band channel filtering (a narrow-band filter (BPF or LPF) having a band narrower than one-channel occupied band width) while the reception/demodulation system is subjected to a wide-band channel filtering (a wide-band filter (BPF or LPF) having a pass band equal to or wider than the one-channel occupied band width).

Abstract: A method for remotely and dynamically controlling adjacent satellite interference comprising monitoring one or more off-axis signals emitted by one or more remote transmitters; determining whether one or more of the off-axis signals is creating adjacent satellite interference (ASI), off axis emissions and inband interference that is higher than a predetermined level of acceptable interference, and transmitting a control signal to at least one of the one or more remote transmitters in response to the determination that the one or more off-axis signals is creating interference that is higher than the predetermined level of acceptable interference, the control signal initiating an adjustment to one or more transmission parameters of the one or more remote transmitters such that interference resulting from the one or more off-axis signals emitted by the one or more remote transmitters is reduced or eliminated.

Abstract: A receiver includes an input section, a plurality of RF sections, an output circuit, and a controller. The input section receives and amplifies a radio frequency (RF) input signal to provide an amplified RF signal, and has a gain input. The plurality of RF sections each have an input for receiving the amplified RF signal, and an output for providing an intermediate frequency signal. The output circuit provides an intermediate frequency output signal in response to an output of at least one of the plurality of RF sections. The controller has an output coupled to the gain input of the input section.

Abstract: A receiver includes a mixer, a filter, a received signal strength indicator, and a control loop. The mixer is adapted to convert the frequency of a received signal. The filter is adapted to filter out undesired signals that may be present in the output signal of the mixer. The received signal strength indicator is adapted to detect blocker (also known as jammer) signals that may be present in the output signal of the low-pass filter and generate a feedback signal in response. The control loop is adapted to vary its bandwidth in response to the feedback signal of the received signal strength indicator. The control loop supplies an oscillating signal to the mixer.

Abstract: A receiver including: an antenna for receiving signals in a plurality of frequency ranges; a plurality of amplifiers, each of the plurality of amplifiers being configured to amplify signals in one of the plurality of frequency ranges; a plurality of receive paths, each of the plurality of receive paths connecting an output of the antenna to an input of one of the plurality of amplifiers, wherein each of the plurality of receive paths includes a power detector for monitoring signal power in the receive path and a switch which can be operated to activate or deactivate the receive path, wherein the switch of each receive path is operable to deactivate the receive path if an overload condition is detected by the power detector of that receive path.

Abstract: A method and system is disclosed for simultaneously down-converting multiple selected signals, such as RF signals, into adjacent ranges in an intermediate frequency band so that the total resulting bandwidth, and thus the sampling rate required to digitize the signal, is minimized. A first signal is down-converted into a range starting at a lowest selected frequency in the IF band. The next signal is down-converted, into a range higher than, but near or adjacent to, the down-converted range of the first signal, and so on. A guard band may be left between the signals if desired. In this way, the selected signals occupy the minimum bandwidth required. When the selection of signals to be down-converted is changed, the frequency ranges are dynamically adjusted so that the signals being down-converted always occupy the lowest ranges of the IF band.

Abstract: A SAW-less receiver includes an FEM interface module, an RF to IF receiver section, and a receiver IF to baseband section. The RF to IF receiver section includes a frequency translated bandpass filter (FTBPF), an LNA, and a mixing section. The FTBPF includes a switching network and baseband impedances. The switching network is operable to frequency translate a baseband filter response to a first RF band frequency response and/or to a second RF frequency band response. The FTBPF filters the inbound RF signal to pass, substantially unattenuated, the first and/or second RF band signal components. The LNA amplifies the first and/or second filtered inbound RF signals and the mixing section mixes the first and/or second amplified inbound RF signals with a corresponding first and/or second local oscillation. The IF to baseband section converts the first and/or second inbound IF signals into first inbound symbol stream(s) and/or second inbound symbol stream(s).

Abstract: A filtering circuit with BAW type acoustic resonators having at least a first quadripole and a second quadripole connected in cascade, each quadripole having a branch series with a first acoustic resonator of type BAW and a branch parallel with each branch having an acoustic resonator of type BAW, the first acoustic resonator having a frequency of resonance series approximately equal to the frequency of parallel resonance of the second acoustic resonator, the branch parallel of the first quadripole having a first capacitance connected in series with the second resonator and, in parallel with the capacitance, a first switching transistor to short circuit the capacitance.

Abstract: An FM receiver is unaware of the modulation level (frequency deviation) of the signal and has to make an estimate of it, or some reasonable time-average of it, and accordingly set the input filter's bandwidth. We calculate modulation by measuring the autocorrelation of the recovered audio signal instead of its peaks, and then applying a peakhold detector. Since FM noise can be modeled to be somewhat uncorrelated, we can expect to get an accurate estimate of signal power while rejecting noise power substantially if we measure a one-sample delayed autocorrelation estimate. Since the above measurement is alike a power measurement, we compute its square root, gain adjust it to obtain a cleaner peak measurement, and then track these clean peaks using a leaky integrator. This gives an estimate of modulation that subdues the effect of the noise.

Abstract: Method for managing power and bandwidth resources in operation over a plurality of links from a hub, said power and bandwidth resources being limited, the method comprising: initially assigning power and bandwidth combinations to individual links according to current conditions pertaining to respective links, each combination having a corresponding resource cost; and controllably changing said initially assigned combinations at respective ones of said links to reduce respective resource costs, thereby to controllably balance an overall resource cost of said plurality of links to lie within available overall power and bandwidth resource limitations.

Abstract: A signal receiver used in a satellite communication system is provided. The signal receiver comprises a first type code generator, a second type code generator, a composite code generator, a correlation module and a determining module. The first type code generator generates a first type code corresponding to a first type signal. The second type code generator generates a second type code corresponding to a second type signal and having a code length N-time longer than that of the first type code. The composite code generator generates a composite code by superimposing N successive first type codes on the second type code. The correlation module correlates the composite code with a cell of a received signal to generate correlation results. The determining module determines a type of the received signal according to correlation results of the composite code with the received signal.

Abstract: A transceiver includes a receiver section and a transmitter section. The receiver section converts an inbound Multiple Frequency Bands Multiple Standards (MFBMS) signal into a down converted signal, wherein the inbound MFBMS signal includes a desired signal component and an undesired signal component. In addition, the receiver section determines spectral positioning of the undesired signal component with respect to the desired signal component and adjusts at least one of the MFBMS signal and the down converted signal based on the spectral positioning to substantially reduce adverse affects of the undesired signal component on the desired signal component to produce an adjusted signal. The transmitter section converts an outbound symbol stream into an outbound MFBMS signal.

Abstract: In one embodiment, the present invention includes a system that having a low noise amplifier (LNA) to receive and amplify a radio frequency (RF) signal, a mixer to receive and downconvert the RF signal to a second frequency signal, a filter to receive and filter the second frequency signal, a demodulator to receive and demodulate the filtered second frequency signal to output demodulated data, and a quality detector to detect a quality of the demodulated data and output a quality indicator based on the data quality. In addition, the system can include a controller coupled to the filter to cause a state of the filter to be stored into a storage responsive to the quality indicator.

Abstract: A bandwidth configuration method includes: A terminal acquires that a narrow bandwidth mode is used at a network side by a downlink transmission signal and/or an uplink transmission signal; and the terminal configures a receiving bandwidth and/or a transmitting bandwidth, where the receiving bandwidth and/or the transmitting bandwidth corresponds to the narrow bandwidth mode at the network side. The terminal side can acquire whether the network side uses the narrow bandwidth technology, and automatically adjust a bandwidth of a corresponding channel at the terminal side when the network side uses the narrow bandwidth technology, so that intra-system performance loss and inter-system interference that are caused by different bandwidth modes between the terminal side and the network side are avoided, thus improving performance of a communication system.

Abstract: An RF transceiver integrated circuit has a novel segmented, low parasitic capacitance, internal loopback conductor usable for conducting IP2 self testing and/or calibration. In a first novel aspect, the transmit mixer of the transceiver is a current mode output mixer. The receive mixer is a passive mixer that has a low input impedance. In the loopback mode, the transmit mixer drives a two tone current signal to the passive mixer via the loopback conductor. In a second novel aspect, only one quadrature branch of the transmit mixer is used to generate both tones required for carrying out an IP2 test. In a third novel aspect, a first calibration test is performed using one quadrature branch of the transmit mixer at the same time that a second calibration test is performed using the other quadrature branch, thereby reducing loopback test time and power consumption.

Abstract: Aspects of a method and system for on-demand linearity in a receiver are provided. In this regard, in a receiver such as on-chip receiver, a strength of a signal received by one or more antennas may be measured and linearity of the receiver may be controlled in response to the measured signal strength. The linearity may be controlled based on signal strength of in-band and/or out-of-band signals and by configuring component(s) of the receiver. Exemplary components may comprise one or more filter, amplifier, mixer, analog-to-digital converter, feedback loop, and equalizer and/or post corrector. Linearity may be increased, by switching one or more feedback loops and/or an equalizers and/or post correctors into a signal path of the receiver. Power consumption may be decreased, at the expense of reduced linearity, by switching one or more feedback loops and/or an equalizers and/or post correctors out of a signal path of the receiver.

Abstract: The dual mode receiver channel select filter includes a filter for a dual mode Bluetooth/Wireless Local Area Network (WLAN) receiver portion of a BT/WLAN transceiver. The filter is a 4th order complex filter and is digitally programmable and reconfigurable. Implemented as the channel select filter for dual-mode receivers, the filter adopts low-IF for Bluetooth and zero-IF for WLAN (IEEE 802.11b). It is based on simple active elements, such as current and voltage followers. The center frequency is digitally tuned through programming active current division networks (CDNs).

Abstract: In one embodiment, a method includes determining in a controller of a radio receiver whether at least one blocker signal is present in a blocking spectrum surrounding a desired radio channel. If no blocker signal is present, a channel filter of a signal processing path of the radio receiver may be controlled to operate at a first bandwidth. If a first blocker signal is present, the channel filter may be controlled to operate at a second bandwidth less than the first bandwidth. If the first blocker signal and a second blocker signal are present on opposing sides of the desired radio channel, the channel filter may be controlled to operate at a third bandwidth less than the second bandwidth, when a beating signal based on the first and second blocker signals is greater than a threshold level.

Abstract: The present invention offers significant improvements in the performance of a radio receiver operating in an environment with high desired band interference. The present invention comprises a high selectivity RF circuit that is located between the antenna and the radio receiver, and utilizes superheterodyne technology to filter adjacent channel interference in the desired band frequency spectrum. This type of interference is problematic for IEEE 802.11 radio receivers that are implemented with the popular direct conversion radio receiver architectures. The present invention may be utilized in many types of radio receivers.

Abstract: A transceiver includes a receiver section and a transmitter section. The receiver section converts an inbound Multiple Frequency Bands Multiple Standards (MFBMS) signal into a down converted signal, wherein the inbound MFBMS signal includes a desired signal component and an undesired signal component. In addition, the receiver section determines spectral positioning of the undesired signal component with respect to the desired signal component and adjusts at least one of the MFBMS signal and the down converted signal based on the spectral positioning to substantially reduce adverse affects of the undesired signal component on the desired signal component to produce an adjusted signal. The transmitter section converts an outbound symbol stream into an outbound MFBMS signal.

Abstract: Provided is a base adjustment device and method of a polyphase filter that can reduce an area and power consumption, and operate at a high speed. The band adjustment device of the polyphase filter according to the present invention includes a voltage-controlled oscillator (VCO), a polyphase filter that inputs an output from the VCO, a mixer that receives an output from the polyphase filter, an envelope detection circuit (envelope detector) that inputs an output from the mixer, and a band control signal generation circuit that inputs an output from the envelope detector.

Abstract: Disclosed is a radio frequency (RF) receiver for receiving a communication channel modulated on one or more carrier frequencies. The receiver may include a gain adjustable RF amplifier, a wideband signal power measurement circuit, and control logic. The control logic may be adapted to use outputs of one or more measurement circuits to classify interfering signals based on measured signal power and spectral proximity to the one or more channel carrier frequencies, and to adjust the gain of the radio frequency amplifier based on the classification.

Abstract: An analog-digital conversion system comprising at least one variable gain amplifier amplifying an input signal e, an analog-digital converter CAN digitizing said signal e, an interference-suppressing digital processing module, processing the digitized signal, also comprises a first automatic gain control AGC loop, called the analog AGC loop, that compares an estimate of the output power of the CAN converter with a control setpoint g1 called the control setpoint of the analog AGC loop, a gain ga used to control the variable gain amplifier being deduced from this comparison. The system also comprises a second automatic gain control AGC loop called the digital loop, said digital loop comparing an estimate of the power after the interference-suppressing digital processing with a predetermined control setpoint gn, the analog AGC loop being controlled by a control setpoint deduced from this comparison.

Abstract: A receiver includes a mixer, a filter, a received signal strength indicator, and a control loop. The mixer is adapted to convert the frequency of a received signal. The filter is adapted to filter out undesired signals that may be present in the output signal of the mixer. The received signal strength indicator is adapted to detect blocker (also known as jammer) signals that may be present in the output signal of the low-pass filter and generate a feedback signal in response. The control loop is adapted to vary its bandwidth in response to the feedback signal of the received signal strength indicator. The control loop supplies an oscillating signal to the mixer.

Abstract: A method includes receiving information flows between users into a basestation of a cellular network, applying a usage accountability framework responsive to predetermined user fairness metrics, bandwidth resources on the network and a history of channel bandwidth variations by the users, and executing bandwidth allocation for the flows between the users responsive to the applying an accountability framework for improving user experience on the network by the users.

Abstract: An integrated wideband receiver includes first and second signal processing paths and a controller. The first signal processing path has an input, and an output for providing a first processed signal, and comprises a first tracking bandpass filter having a first integrated inductor. The second signal processing path has an input, and an output for providing a second processed signal, and comprises a second tracking bandpass filter having a second integrated inductor. The controller is for enabling one of the first and second signal processing paths corresponding to a selected channel of a radio frequency (RF) input signal to provide an output signal. The controller, the first integrated inductor, and said second integrated inductor are formed on a single integrated circuit chip.

Abstract: A method for controlling a wireless communication apparatus includes request processing for requesting information regarding traffic to an access point, measurement processing for performing data transmission and reception wirelessly on the basis of the information regarding traffic requested by the request processing and measuring traffic during the data transmission and reception, and re-request processing for updating the information regarding traffic to be requested to the access point so as to correspond to the traffic measured by the measurement processing and re-requesting the updated information.

Abstract: Present software-defined radios (SDR) employ front end circuits that contain multiple receivers and transmitters for each band of interest, which is inflexible, expensive and power inefficient. A programmable front end circuit is implemented on a CMOS device and is configurable to transmit and receive signals in a wide band of frequencies, thereby providing an adaptable transmitter and receiver operable with current and future wireless networking technologies.

Abstract: The present invention offers significant improvements in the performance of a radio receiver operating in an environment with high desired band interference. The present invention comprises a high selectivity RF circuit that is located between the antenna and the radio receiver, and utilizes superheterodyne technology to filter adjacent channel interference in the desired band frequency spectrum. This type of interference is problematic for IEEE 802.11 radio receivers that are implemented with the popular direct conversion radio receiver architectures. The present invention may be utilized in many types of radio receivers.

Abstract: Embodiments of systems and methods for multi-radio coordination of heterogeneous wireless networks are generally described herein. Other embodiments may be described and claimed.

Abstract: A transceiver includes a receiver section and a transmitter section. The receiver section converts an inbound Multiple Frequency Bands Multiple Standards (MFBMS) signal into a down converted signal, wherein the inbound MFBMS signal includes a desired signal component and an undesired signal component. In addition, the receiver section determines spectral positioning of the undesired signal component with respect to the desired signal component and adjusts at least one of the MFBMS signal and the down converted signal based on the spectral positioning to substantially reduce adverse affects of the undesired signal component on the desired signal component to produce an adjusted signal. The transmitter section converts an outbound symbol stream into an outbound MFBMS signal.

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 receiver includes an oscillator for generating a local oscillator signal, a frequency converter for heterodyning a received signal of one frequency band or a plurality of frequency bands into an intermediate frequency (IF) signals with using the local oscillator signal, a filter connected to an output of the frequency converter and having a cut-off frequency changeable, an analog-digital (AD) converter connected to an output of the filter to convert an analog signal of one frequency band or a plurality of frequency bands into a digital signal, a pre-stage detector connected to an output of the AD converter or connected between the filter and the AD converter to detect a signal level, and a controller for controlling the cut-off frequency of the filter based on the signal level detected by the pre-stage detector.

Abstract: A receiver includes an input to receive data of a pilot channel having a carrier frequency associated therewith, and a first unit to obtain a quantity, wherein the quantity depends on a frequency broadening of the received data and a frequency shift of the received data with respect to the carrier frequency. The receiver also includes a second unit to adjust the bandwidth of a channel estimation unit, wherein the adjustment depends on the quantity.

Abstract: Aspects of a method and system for on-demand signal notching in a receiver. In this regard, signal strength measurements of a received signal may enable detection of unwanted signal component(s) and one or more filters in an on-chip receiver may be configured in response to the measurements. The filter(s) may additionally be configured based on power consumption of the filter(s). Signal measurements and/or the corresponding configuration may be performed real-time. The filter(s) may be configured such that a notch in a frequency response of the filter(s) is centered at or near the unwanted component. In this manner, the unwanted component(s) may be filtered out. The filter(s) may be configured, for example, by switching one or more filter stages and/or components into and/or out of a signal path and/or by tuning one or more variable circuit elements within the filter(s).

Abstract: A network includes a first node and a second node and data frames are transmitted from the first node to the second node. Each of the data frames carry information belonging to one of a plurality of data flows. In a flow control unit (125) there is an estimate or measure determining unit (1201) for determining for each of the data flows, at the ends of first time periods having a predetermined first length, an estimate of or a measure representing the total number of received data frames that have been faulty during the first time period. A reference calculating unit (1101) is connected to the estimate or measure determining unit for calculating, based on the determined estimate or measure, a bandwidth capacity reference value determining the currently maximum allowable bandwidth for transmission from the data transmitting node to the data receiving node. The first node can be a radio network controller and the second node a radio base station, the data frames forwarded in an HS-DSCH over an Iub interface.

Abstract: A receiver includes a static I/Q calibration block and a correlation/integration block. The static I/Q calibration block is configured to substantially eliminate mismatches between in-phase and quadrature components of a portion of the spectrum having associated I/Q mismatches that are relatively frequency-independent. The correlation/integration block is configured to substantially eliminate mismatches between the in-phase and quadrature components of portions of the spectrum having associated I/Q mismatches that are relatively frequency-dependent in accordance with a pair of signals generated by the static I/C calibration block.

Abstract: Methods and apparatus for computing the carrier frequency of a transmitter using frequency modulated digital data to compensate for frequency shifting of the transmitter and the receiver local oscillators and for bandwidth adjustment of the receiver's filter. In particular, methods and apparatus are disclosed for binary systems transmitting “1” and “0” data using decoded or undecoded received signals.

Abstract: A burst demodulator and method of obtaining a signal of interest from many signals of interest within a composite signal. Implementations may include receiving a composite signal, centering a replica of the interfering signal relative to the composite signal, reducing the composite signal to the bandwidth of a desired signal of interest, and canceling the remaining portion of the interfering signal.

Abstract: Line system design techniques are provided for use in performing routing and coloring operations associated with one or more demands. In one aspect of the invention, a technique for designing a line system comprises the following steps/operations. A set of one or more demands is obtained for use in computing the line system design. The line system design is then represented as a graph in accordance with a graph coloring operation wherein colors represent bandwidths such that bandwidths are assigned and the one or more demands are routed so as to attempt to achieve a minimum total design cost. The line system being designed may be an optical line system.

Abstract: An approach for load balancing is disclosed. A user load is determined based upon data queued for transmission at each of the terminals. In addition, an inroute load corresponding to loading of inroutes serving the terminals is determined. A user-to-inroute distribution that minimizes variation of the inroute load is generated. The user-to-inroute distribution maps the user load to the inroutes. The user load is reassigned to the inroutes based on the determined user-to-inroute distribution. This arrangement has particular applicability to a satellite network that provides data communication services.

Abstract: An analog radio receiver can change a noise suppression parameter appropriate for a sound to be reproduced. The analog radio receiver includes a sound category determining unit for determining a category of a sound to be reproduced from an input signal, and a selecting unit for selecting, on the basis of the category determined by the sound category determining unit, a noise suppression parameter such as passband of the IF filter, blend value of the stereo blend unit, high-cut value of the high-cut unit, response rate of the soft mute unit, and the like, wherein the IF filter, the stereo blend unit, the high-cut unit, the soft mute unit suppress noises of the input signal on the basis of the noise suppression parameter selected by the selecting unit.

Abstract: A transceiver includes a receiver section and a transmitter section. The receiver section converts an inbound Multiple Frequency Bands Multiple Standards (MFBMS) signal into a down converted signal, wherein the inbound MFBMS signal includes a desired signal component and an undesired signal component. In addition, the receiver section determines spectral positioning of the undesired signal component with respect to the desired signal component and adjusts at least one of the MFBMS signal and the down converted signal based on the spectral positioning to substantially reduce adverse affects of the undesired signal component on the desired signal component to produce an adjusted signal. The transmitter section converts an outbound symbol stream into an outbound MFBMS signal.

Abstract: In a frequency converting system, an input signal x(t) is supplied to a signal branching section for dividing a predetermined frequency domain into M bands, extracting signal components of the respective divided bands. The respective signal components and local signals each including a frequency difference corresponding to a predetermined intermediate frequency with respect to a center frequency of each band are input to a frequency converting part. The signals of the respective divided bands are converted into signals of intermediate frequency bands each including the predetermined intermediate frequency as the center frequency, the conversion outputs are sampled by using a common clock signal, whereby the conversion outputs are converted into digital signals. Further, after being subjected to phase correction processing, the digital signals are subjected to frequency conversion and combination processing by a signal regeneration part.

Abstract: A mixer is configured to sample a received input signal at a predefined oscillator frequency to generate a sampled input signal, and to switch a polarity of the sampled input signal at a predefined polarity switching frequency to generate a polarity switched sampled input signal.

Abstract: An FM audio receiver can include a mono/stereo detector that causes the audio receiver to output either a monophonic or a stereophonic signal based on a received pilot tone energy. An accurate operation of the receiver, including but not limited to correct decoding of monophonic/stereophonic reception, can be based on the receiver operating with the same rated maximum system deviation (RMSD) as the received signal itself. Aspects of the disclosure describe a system and method of detecting and matching a receiver's RMSD to that of a received signal by demodulating a carrier bearing a an input signal over a first bandwidth, extracting a pilot energy signal from the input signal, and demodulating the carrier bearing the input signal over a second bandwidth if the pilot energy signal is within a pilot energy range for a first predetermined amount of time.

Abstract: An apparatus includes first and second filters and a bandwidth control circuit. The first filter operates as part of a first oscillator in a first mode and filters a first input signal and provides a first output signal in a second mode. The second filter operates as part of a second oscillator in the first mode and filters a second input signal and provides a second output signal in the second mode. The bandwidth control circuit adjusts the bandwidth of the first and second filters in the first mode, e.g., adjusts the oscillation frequency of each oscillator to obtain a target bandwidth for an associated filter. The apparatus may further include first and second gain control circuits. Each gain control circuit may vary the amplitude of an oscillator signal from an associated oscillator and/or set a gain of an associated filter in the first mode.

Abstract: The IFBPF (80) can variably set a passband width (WF) and an attenuation slope (KF). The bandwidth control circuit (102), which is constituted in hardware, controls the WF in accordance with the receiving state, which is composed of a combination of the receiving electric field intensity, the modulation degree, and the intensity of the adjacent-channel interference. A microcomputer (54) controls the KF on the basis of a program stored in a nonvolatile memory (60) and finely adjusts the effective passband width. Control of the WF contradictory for prevention of audio distortion and control of adjacent-channel interference is required when high modulation and adjacent-channel interference exist in a weak electric field state, and the setting becomes difficult. In this particular case, a configuration in which the KF can be modified by a program allows an advantageous receiving state to be readily obtained.