Abstract: In an ultra wide bandwidth communications system a spreading waveform is generated in a transmitter. The spreading waveform is shaped according to shape data, which specifies desirable and undesirable frequency ranges. The shaped spreading waveform is combined with source data and fed to a voltage controlled oscillator for modulation. The combined modulation signal is then transmitted to a receiver so that a spectrum of the transmitted signal has a predetermined shape.

Abstract: A method and arrangement for forming an address for use in signal predistortion. The arrangement is used to form a corrector table address employed in the signal predistortion to compensate for signal distortions. The signal distortions are compensated for using corrector coefficients that are placed in the corrector table and retrieved from the table on the basis of the address. The arrangement includes calculation means that, on the basis of the received signal, calculate a result corresponding to the squaring of a received signal. The arrangement further comprises summing means that, if required, sum up the results corresponding to the squaring, the sum forming a base address. The arrangement further comprises error correction means that correct the calculated base address by means of an address correction value.

Abstract: An improved satellite communications system allows for greater spectral efficiency by requiring just two frequencies for wireless communications between a first ground-based station and a second ground-based station via a satellite. Both the first station and the second station use the first frequency to transmit signals to the satellite; the satellite transponds the signals it receives on the first frequency to the second frequency and transmits the signals to the first and second stations on the second frequency. Use of two frequencies in such a manner results in some own-signal interference. The first station preferably stores its outgoing signals in memory and then subtracts out these stored signals to eliminate the its own-signal interference. The second station may likewise store and subtract out its transmissions, but this is not required.

Abstract: The radio resource management server 1 receives radio link quality information measured by the radio base station 2 and radio link quality information measured by the radio base station 3 and thus detects the occurrence of interference. Upon the occurrence of the interference, the transmission power of the radio base station causing the occurrence of interference is controllably reduced to suppress the interference. In the method of controllably varying the transmission power of a radio base station, depending on the number of radio terminals or traffic volume, oscillation of a service area occurs. However, according to the present invention, the transmission power is changed on the occurrence of interference, without depending on the number of radio terminals or traffic volume, so that the area oscillation does not occur after the transmission power has been once stabilized.

Abstract: A Power Amplifier (PA) exhibits non-linear characteristics as a result of Amplitude Modulation-Phase Modulation (AM-PM) conversions resulting in intermodulation. Inter-modulation affects the RF signal spectrum at the output of the PA. The invention presents a method and apparatus for reducing intermodulation generated at the output of a PA as a result of AM-PM conversion. Presented is a RF power detector utilized in feedback control circuitry where the induction of odd-order harmonics into the feedback path acts to reduce AM-PM intermodulation at the output of the PA. The RF power detector comprises an detector input for receiving RF power and a detector output containing a pre-corrected detected voltage. The RF power detector comprises a pre-correcting circuit for generating odd-order harmonics at a specific power level. The pre-correcting circuit induces odd-order harmonics into the detected portion of output power allowing feedback control circuit to compensate for AM conversions.

Abstract: A method for suppressing electronic equipment operation in the concurrence of modes condition, the equipment having at least one amplification device, includes the step of applying a random modulating signal to at least one node of the amplification device, wherein a transfer ratio or transfer function of the amplification device is modulated. An electronic apparatus adapted to suppress operation in the concurrence of modes condition, the apparatus having at least one amplifier, includes a structure for generating a sequence of random numbers, a device for converting the sequence of random numbers into a random modulating signal, and a structure for applying the random modulating signal to the amplifier, wherein a transfer ratio or transfer function of the amplifier is modulated. The electronic apparatus can include a cellular phone.

Abstract: A calibration device detects a delay or amplitude characteristic of a radio reception section. The characteristic is detected using a calibration signal of a band equal to or close to that used for radio communication.