Abstract: An RF receiver includes a variable gain amplifier which amplifies a received RF signal based on a gain control signal, a peak detector which determines a peak value of the amplified signal, a mixer which downconverts the amplified signal to a downconverted signal, and a control unit which determines whether or not an interfering signal other than an adjacent channel interfering signal is received. If the control unit determines that the interfering signal other than the adjacent channel interfering signal is received, the control unit generates the gain control signal so that the range of the peak value is a first range; otherwise, the control unit generates the gain control signal so that the range of the peak value is a second range. The upper and lower bounds of the second range are lower than the upper and lower bounds of the first range, respectively.

Abstract: A sampling filter device wherein the filter characteristic is variable without using a control signal of a complicated waveform is provided. A sampling filter device 105 has integration capacitors 130 and 131, an integration time adjustment section 180, and a plurality of switches 100, 101, 110, and 111. Input current is integrated in different time duration with one clock and is stored in the integration capacitors 130 and 131 and charges stored in the integration capacitor from several clocks before to one clock before are added and the result is output. When charge is stored in the integration capacitors 130 and 131 with each clock, the integration time duration is changed, whereby it is made possible to weight and add output charge and the filter characteristic changes.

Abstract: A multimode wireless communication apparatus that supports plural wireless communication systems and switches wireless communication systems to communicate. The apparatus includes a signal processor capable of switching wireless communication systems by plural manners; and a controller that directs to the signal processor a combination of manners of switching wireless communication systems according to a communication environment. The signal processor switches wireless communication systems according to the combination of manners of switching wireless communication systems directed from the controller.

Abstract: A wireless terminal involving small redundancy that can be reconfigured to a configuration compatible with a plurality of systems using the hardware resources compatible with one system is provided. A wireless terminal 100A is compatible with an OFCDM system and has a signal processing section 151, a synchronous detection section 162, etc. The signal processing section 151 performs Fourier transform when the wireless terminal is compatible with the OFCDM system; the signal processing section 151 performs Fourier transform and inverse Fourier transform compatible with an OFDM system when the wireless terminal is compatible with the OFDM system and a CDMA system. When the wireless terminal is compatible with the OFCDM system, the synchronous detection section 162 uses taps used in the systems when the wireless terminal is compatible with the OFDM system and the CDMA system.

Abstract: A radio communication apparatus capable of alleviating a burden in setting a transmission format and suppressing increases in the scale of the apparatus. In this apparatus, space multiplexing adaptability detection section (108) detects space multiplexing transmission adaptability for divided bands (DB-1 to DB-Nd) obtained by dividing a communication band to which Ns subcarrier signals belong in multicarrier transmission and to which a plurality of subcarrier signals belong, and outputs the detection results (#1 to #Nd). Transmission format setting section (110) sets a transmission format when carrying out radio transmission based on the detection results (#1 to #Nd) from space multiplexing adaptability detection section (108).

Abstract: Provided are a direct sampling circuit and a receiver using a discrete time analog process and having a filter effect of a steep attenuation characteristic in a narrow-pass band without lowering a sampling rate. In a discrete time direct sampling circuit (13), the positive phase side and the inverse phase side are both sampled by a local signal for a differential current output of a differential voltage/current conversion unit (1011) and electric charge is accumulated in a charge sampling capacitor. The latest accumulated charge at the positive phase side and charge accumulated at the inverse phase side before a predetermined number of samples are combined with the charge accumulated in a history capacitor (1043) in the past. Thus, it is possible to realize equivalently high-degree FIR filter characteristic.

Abstract: A radio communication apparatus capable of alleviating a burden in setting a transmission format and suppressing increases in the scale of the apparatus. In this apparatus, space multiplexing adaptability detection section (108) detects space multiplexing transmission adaptability for divided bands (DB-1 to DB-Nd) obtained by dividing a communication band to which Ns subcarrier signals belong in multicarrier transmission and to which a plurality of subcarrier signals belong, and outputs the detection results (#1 to #Nd). Transmission format setting section (110) sets a transmission format when carrying out radio transmission based on the detection results (#1 to #Nd) from space multiplexing adaptability detection section (108).

Abstract: There are provided a sampling filter that enables a filter characteristic to be adjusted flexibly, and a radio communication apparatus equipped with this sampling filter. A sampling filter apparatus (100) is equipped with four integration units (150-1 through 150-4) corresponding to the number of filter taps, and some of the integration units (150-1 through 150-4) include an integrator having an MEMS structure. By this means, a charge amount (accumulated charge amount) of a received signal integrated by an integrator can be adjusted by adjusting the capacity of an integrator having an MEMS structure. A received signal amount emitted from an integration unit can also be adjusted by adjustment of the integration amount of a received signal, enabling the filter characteristic of the sampling filter apparatus (100) to be adjusted flexibly.

Abstract: A digital filter is provided for radio communication processing capable of dynamically modifying the characteristic and simultaneously processing a plurality of systems. In the digital filter, calculation core groups capable of modifying function are arranged and connected to one another by an input interface unit and an output interface unit. When the communication mode is modified, the number of calculation resources to be used and setting contents are decided according to the setting candidate of the filter characteristic required and the calculation resource empty state.

Abstract: An RF receiver includes a variable gain amplifier which amplifies a received RF signal based on a gain control signal, a peak detector which determines a peak value of the amplified signal, a mixer which downconverts the amplified signal to a downconverted signal, and a control unit which determines whether or not an interfering signal other than an adjacent channel interfering signal is received. If the control unit determines that the interfering signal other than the adjacent channel interfering signal is received, the control unit generates the gain control signal so that the range of the peak value is a first range; otherwise, the control unit generates the gain control signal so that the range of the peak value is a second range. The upper and lower bounds of the second range are lower than the upper and lower bounds of the first range, respectively.

Abstract: A sampling mixer includes TAs (transconductance amplifiers), an in-phase mixer section connected to the TA and the TA, an opposite-phase mixer section connected in parallel with the in-phase mixer section, and a signal generator for generating a control signal for the in-phase mixer section and the opposite-phase mixer section respectively. The IIR filter using signals that underwent a current conversion by using the different transconductances is constructed, so that the filter characteristic can be designed by a weighting of the transconductance in addition to a capacitance ratio. As a result, the wide-band filter characteristic and the band-pass filter characteristic can be obtained, and deterioration of the receiving sensitivity can be suppressed by designing the filter characteristic suitable for the radio communication system.

Abstract: A sampling filter of such circuitry as not requiring a high frequency REF signal even if the number of decimation is decreased. In the sampling filter, the rotate capacitor in each switched capacitor circuit including Cr (7a-7d) arranged in four parallel arrays operates in four phases of integration, discharge, reset and feedback different from each other at the same timing. Consequently, a control signal for driving the switched capacitor circuit is used commonly. As a result, the circuit scale of a DCU (104) is reduced and the frequency of the REF signal can be lowered to the frequency of an LO signal even in operation without decimation.

Abstract: A wireless communication apparatus and a communication control method wherein even if there occurs a change in communication control information due to a function change, an appropriate correction is implemented to improve the communication quality. A wireless communication apparatus (100) comprises a plurality of reconfigurable function parts (reconfigurable function modules (1031)) that reconfigure functions related to communication to perform digital signal processings according to a plurality of communication formats; and a communication operation control function part that controls the communication operation. Each of the reconfigurable function parts includes a property register (10311) in which the communication control information is written.

Abstract: A wireless terminal involving small redundancy that can be reconfigured to a configuration compatible with a plurality of systems using the hardware resources compatible with one system is provided. A wireless terminal 100A is compatible with an OFCDM system and has a signal processing section 151, a synchronous detection section 162, etc. The signal processing section 151 performs Fourier transform when the wireless terminal is compatible with the OFCDM system; the signal processing section 151 performs Fourier transform and inverse Fourier transform compatible with an OFDM system when the wireless terminal is compatible with the OFDM system and a CDMA system. When the wireless terminal is compatible with the OFCDM system, the synchronous detection section 162 uses taps used in the systems when the wireless terminal is compatible with the OFDM system and the CDMA system.

Abstract: The sampling filter apparatus 100 includes the first sampling switch 130, the second sampling switch 131, the first integrator 1500 for integrating the charge input from the first sampling switch, the second integrator 1501 for integrating the charge input from the second sampling switch, a plurality of integrators connected to both of the first integrator and the second integrator via a charging switch, respectively, the control section 140, a plurality of charging switches, and a plurality of discharge switches. A charge input from the sampling switch 130, a charge accumulated in the capacitor 1500 and a charge accumulated in a capacitor 1510 are shared by the capacitor 1500, the capacitor 1510 and the capacitor 1530, and the charge accumulated in the capacitor 1530 is output.

Abstract: Provided is a fast Fourier transformation circuit capable of optimizing an operation resource while matching a plurality of communication systems. In this circuit, an FFT circuit (100) comprises a first FFT operation unit (110) for subjecting two-parallel 2<M?1> digital signals to FFT operations of (M?1) steps, a second FFT operation unit (120) for subjecting 2<N> digital signals to FFT operations of (N?M+1) steps, and a third FFT operation unit (130) for subjecting 2<M> digital signals to an FFT operation of one step. The output signal of the first FFT operation unit (110) is subjected to the FFT operation by the second FFT operation unit (120) and the third FFT operation unit (130) thereby to perform the FFT operations of 2<N> points and 2<M> points simultaneously.

Abstract: A radio communication apparatus capable of alleviating a burden in setting a transmission format and suppressing increases in the scale of the apparatus. In this apparatus, space multiplexing adaptability detection section (108) detects space multiplexing transmission adaptability for divided bands (DB-1 to DB-Nd) obtained by dividing a communication band to which Ns subcarrier signals belong in multicarrier transmission and to which a plurality of subcarrier signals belong, and outputs the detection results (#1 to #Nd). Transmission format setting section (110) sets a transmission format when carrying out radio transmission based on the detection results (#1 to #Nd) from space multiplexing adaptability detection section (108).

Abstract: It is an object of the present invention to provide a sampling mixer and a receiver, capable of optimizing a sampling rate of an output signal in response to a fractional band of a modulation band with respect to an RF frequency of the received signal. A sampling mixer of the present invention, includes a history capacitor 6 for integrating a received signal that is converted in terms of current in a continuous time, rotation capacitors 7 to 14 for repeating an integration and a discharge of an input signal, a digital controller 104 for controlling integration periods of the rotation capacitors 7 to 14, and a controlling portion 105 for controlling discharges of the rotation capacitors 7 to 14, wherein the number of the rotation capacitors 7 to 14 connected at a time to a buffer capacitor 15 is switched in answer to a fractional band of the modulation band with respect to a RF frequency.

Abstract: The present invention has an object to provide a sampling filter apparatus and a wireless communication apparatus, which are capable of changing a filter characteristic without employing complex waveforms as control signals, and also, capable of performing filtering process operations without performing a decimation, while utilizing a wide frequency space. A sampling filter apparatus 100 includes a controller 140, a plurality of integrators 150 to 154, a plurality of switches 130, 160 to 164, 170 to 174, 180 to 184, and a plurality of voltage/current converters 120 to 123. An inputted current is stored in four pieces of integrators selected among the plurality of integrators 150 to 154 by one clock, and electric charges which have been stored from four preceding clocks up to one preceding clock are added to each other so as to output the added electric charges from the remaining one integrator.

Abstract: A multimode communication apparatus capable of varying a function of a signal processing portion without external resource control is provided. The multimode communication apparatus includes a radio portion 103 for conducting a radio communication, a plurality of signal processing devices 105, 106 whose function can be varied by resource control, and a storing portion 109 for storing data defining a resource controlling function that is executable on a plurality of signal processing devices 105, 106. Since the resource controlling function is furnished into any of the signal processing devices 105, 106, the function of the signal processing devices 105, 106 can be varied not to provide a resource controlling portion to the outside of the signal processing device.