Abstract: A method and circuitry for pre-conditioning an electrical signal. The method comprises limiting the strength of the signal to not exceed a limit signal strength corresponding to the onset of substantial non-linear response of an amplifier to which the limited signal is to be supplied for amplification.

Abstract: A system and method to optimize the efficiency of an amplifier device is provided by the including a non-linear amplifier in a mobile radio device. A phase displaced signal in relation to the input signal is respectively produced in the amplifier device with a non-linear power amplifier and in a plurality of push-pull successive phase modifiers, and the outputs of the phase modifier are connected by a passive component.

Abstract: An antenna-switching diversity receiver is capable of switching antennas without bringing about deterioration of reception characteristics even when applied to the CDMA communication method. A TFCI bit decoding/determination unit decodes TFCI bits that have been extracted by a TFCI bit extractor and determines the presence or absence of communication control data based on the TFCI bits that have been decoded. An antenna switching control unit uses a timer to check for the presence or absence of communication control data in each of fixed time intervals based on the determination results of the TFCI bit decoding/determination unit and then controls the antenna switch in intervals that lack communication control data to measure the reception level of the common pilot channel at the other antenna that differs from the antenna that is currently receiving and then select the antenna having the higher reception level.

Abstract: The circuit size of a diversity receiver for an orthogonal frequency division multiplexing signal is reduced, and the diversity effect is increased, by providing a power ratio comparator that calculates a difference value as a ratio of powers derived from channel estimation results for subcarrier components received from two antennas (11), (21) and compares the calculated difference value with a predetermined threshold, and a selective/equal gain combining selector (33) that outputs one of the received demodulated signals when the comparison result indicates that the calculated difference value is greater than the threshold value.

Abstract: A radio wave receiver for receiving radio waves having a predetermined frequency, the receiver comprises an antenna, an variable capacitor connected to the antenna, a memory, and a controller which determines an optimum capacitance of the variable capacitor with which the radio wave receiver is in a predetermined reception state and writes optimum capacitance data into the memory and, controls the variable capacitor based on the optimum capacitance data.

Abstract: A WLAN (Wireless Local Area Network) communication device comprising a WLAN frequency synthesizer for generating a synthesizer signal suitable for modulating a transmission signal and/or demodulating a reception signal and corresponding methods and integrated circuit chips are provided. The WLAN frequency synthesizer comprises a reference oscillator for generating a first reference clock signal, a fractional-N PLL (Phase-Locked Loop) unit for receiving a second reference clock signal and converting the second reference clock signal into the synthesizer signal, and a frequency multiplier for receiving the first reference clock signal and converting the first reference clock signal into the second reference clock signal to be forwarded to the fractional-N PLL unit by multiplying the frequency of the first reference clock signal by a multiplication factor. Embodiments may provide shorter settling times and/or enhanced spurious suppression of the fractional-N PLL unit.

Abstract: A smart antenna steering algorithm performs a periodic re-scan at an end of a sustained use period and before a next sustained use period. During a sustained use period, a re-scan of the other antenna beams is not performed. The periodic re-scan is performed on alternate antenna beams that were selected when the preferred antenna beam was selected. The steering algorithm monitors a quality metric of the alternate antenna beams as well as a quality metric for the preferred antenna beam. If the quality metric of the preferred antenna beam is less than the quality metrics of anyone of the alternate antenna beams, then the alternate antenna beam corresponding to the quality metric having a higher value is selected for the next sustained use period.

Abstract: An object of the present invention is to provide a receiver, a digital-analog converter and a tuning circuit in which temperature compensating components can be formed on a semiconductor substrate while reducing component costs. An FM receiver 100 is constituted by including an antenna 1, a high frequency receiving circuit 2, a local oscillator 3, two digital-analog converters (DACs) 4, 6, a control section 8, a mixing circuit 9, an intermediate frequency amplification circuit 10, a detection circuit 11, a low frequency amplification circuit 12 and the speaker 13. The DACs 4, 6 have a predetermined temperature coefficient, of which output voltage is changed in accordance with ambient temperature. When a characteristic of VCO 31 is changed with variations of ambient temperature so as to cause a control voltage applied to the VCO 31 to be changed, output voltages of the DACs 4, 6 are also changed similarly.

Abstract: An electric circuit suitable for use as a radio receiver or part of a radio receiver, the electric circuit comprising amplification means, frequency mixer means, and filter means, wherein the frequency mixer mans is configurable to down-convert a wanted component of the amplified input signal to one of at least two intermediate frequency bands, and the filter means is dynamically reconfigurable between a first filter configuration which provides a first operating mode, and a second filter configuration which provides a second operating mode.

Abstract: A transmission control section 101 temporarily stores a transmission signal, outputs the stored transmission signal to a coding section 102 and outputs transmission timing information to a counter section 107. A preamble insertion section 104 inserts AGC preambles corresponding to the number set by a preamble number control section 110 into the transmission signal. The preamble number control section 110 compares a transmission time interval input from a subtraction section 109 with a threshold, decides to insert ten AGC preambles into the transmission signal when the transmission time interval is equal to or greater than the threshold and decides to insert five AGC preambles into the transmission signal when the transmission time interval is smaller than the threshold. By so doing, it is possible to make the transmission efficiency compatible with the error rate characteristic.

Abstract: Herein disclosed are a portable information terminal and a communication system according to the present invention. The portable information terminal comprises an information providing unit 109 for providing information in accordance with a providing method which the information providing unit 109 is set to, a providing pattern data storage unit 104 for storing therein pattern data associating each of the providing methods with a location and a moving speed, a sensor unit 102 for detecting a current location and a moving speed, and a providing method control unit 106 for obtaining the providing method associated with the current location and the moving speed from the providing pattern data storage unit 104 and controlling an output port 108 to change the providing method previously set to the information providing unit 109 to have the information provided in accordance with the providing method indicated by the obtained pattern data.

Abstract: A radio transmitter, comprising: a feedback loop (314) which feedback loop comprises a variable attenuator and a signal analyser, means (300, 302, 304, 306, 308, 310, 312) for transmitting a signal on a predetermined radio channel, means (308) for changing attenuation level and for attenuating the feedback signal, means (316) for defining power levels on the radio channel and on the adjacent channels, means (312) for analysing the power levels to generate first and second results of analysis and for comparing the first and second results of analysis, means (318) for delaying a transmitted signal to derive a reference signal, means (312) for comparing the feedback signal and the reference signal to generate an error vector and means (320) for generating a test alarm.