Abstract: A wireless communication system includes a server and a plurality of wireless communication devices representing nodes assigned to the server. The server sends notification information in which the starting position of a frame is specified. Each wireless communication device includes a notification information processing unit that receives notification information; and includes a communication processing unit that performs communication of the Time Division Duplex (TDD) type, and performs communication of the Carrier Sense Multiple Access (CSMA) type during the periods of time between downlink time period and uplink time period of the TDD type.

Abstract: An apparatus for connection control includes: a memory; a processor coupled to the memory and configured to execute a receiving process configured to receive, via a second wireless apparatus installed near a first wireless apparatus, identification information transmitted from a terminal that is located within a range of a first signal from the second wireless apparatus, the identification information being information configured to identify the terminal, and execute a transmitting process configured to transmit configuration information to the terminal via the second wireless apparatus when the terminal identified by the identification information is allowed to access to the first wireless apparatus that acts as a connection point for the terminal, the configuration information including a parameter for accessing the first wireless apparatus.

Abstract: A radio apparatus includes an amplifier that amplifies electrical power of a signal that is wirelessly transmitted, and a processor that executes a process including: performing, by using a distortion compensation coefficient that compensates distortion generated in the amplifier, distortion compensation of an input signal; reading, from a predetermined memory, a threshold that varies in accordance with the electrical power of the input signal; and comparing the read threshold with a monitoring target which includes the distortion compensation coefficient used with respect to the input signal to monitor whether an abnormality is present in the distortion compensation of the input signal.

Abstract: A radio apparatus includes an amplifier that amplifies electrical power of a signal that is wirelessly transmitted, and a processor that executes a process including: performing, by using a distortion compensation coefficient that compensates distortion generated in the amplifier, distortion compensation of an input signal; reading, from a predetermined memory, a threshold that varies in accordance with the electrical power of the input signal; and comparing the read threshold with a monitoring target which includes the distortion compensation coefficient used with respect to the input signal to monitor whether an abnormality is present in the distortion compensation of the input signal.

Abstract: an amplifier amplifies electrical power of signals. A calculating unit calculates a cumulative value for each of first samples and second samples, between which a difference in electrical power or phase is within a first range, in a first sample group and a second sample group corresponding to a first signal that is a signal before amplification in the amplifier and a second signal that is a signal after amplification in the amplifier. Then, the calculating unit calculates, by using the calculated cumulative value, a phase difference between the first signal and the second signal. The correction unit corrects the phase difference by using a correction amount calculated from the phase difference. The updating unit updates, by using the first signal and the second signal of which the phase difference is corrected, a distortion compensation coefficient that is used to compensate nonlinear distortion generated in the amplifier.

Abstract: an amplifier amplifies electrical power of signals. A calculating unit calculates a cumulative value for each of first samples and second samples, between which a difference in electrical power or phase is within a first range, in a first sample group and a second sample group corresponding to a first signal that is a signal before amplification in the amplifier and a second signal that is a signal after amplification in the amplifier. Then, the calculating unit calculates, by using the calculated cumulative value, a phase difference between the first signal and the second signal. The correction unit corrects the phase difference by using a correction amount calculated from the phase difference. The updating unit updates, by using the first signal and the second signal of which the phase difference is corrected, a distortion compensation coefficient that is used to compensate nonlinear distortion generated in the amplifier.

Abstract: A distortion compensation device compensates a non-linear distortion of a power amplifier included in a wireless communication apparatus that employs the power amplifier to amplify a transmission signal and that transmits the amplified transmission signal. The distortion compensation device includes a bit adjusting unit that, when a width of a distribution of a first parameter among a plurality of calculated parameters is equal to or smaller than a predetermined level, adjusts a bit number of a first address corresponding to the first parameter to be a value obtained by decreasing a first reference bit number and adjusts a bit number of a second address corresponding to a second parameter other than the first parameter to be a value obtained by increasing a second reference bit number.

Abstract: A radio device includes: a peak power reducer that reduces, according to a peak power of a multi-carrier signal obtained by a multiplexing of a plurality of carrier signals, a gain of the carrier signals before the multiplexing; and an output power corrector that corrects a power of the carrier signals before the multiplexing using a power correction value according to an occupied bandwidth of the multi-carrier signal.

Abstract: A distortion compensation device compensates a non-linear distortion of a power amplifier included in a wireless communication apparatus that employs the power amplifier to amplify a transmission signal and that transmits the amplified transmission signal. The distortion compensation device includes a bit adjusting unit that, when a width of a distribution of a first parameter among a plurality of calculated parameters is equal to or smaller than a predetermined level, adjusts a bit number of a first address corresponding to the first parameter to be a value obtained by decreasing a first reference bit number and adjusts a bit number of a second address corresponding to a second parameter other than the first parameter to be a value obtained by increasing a second reference bit number.

Abstract: A distortion compensation apparatus includes: a storage unit that stores a distortion compensation coefficient; a distortion-compensation-coefficient selecting unit that takes a logarithm of power of an input signal and exponentiates a value obtained by taking the logarithm, and that selects a distortion compensation coefficient that is stored in the storage unit according to a value obtained by the exponentiating; a distortion-compensation processing unit that acquires the selected distortion compensation coefficient from the storage unit, and that performs distortion compensation processing on the input signal to the distortion-compensation-coefficient selecting unit using the acquired distortion compensation coefficient; an amplifier that amplifies the signal subjected to the distortion compensation processing; and a distortion-compensation-coefficient updating unit that updates the distortion compensation coefficient stored in the storage unit based on the amplified signal and the input signal to the dist

Abstract: A distortion compensation apparatus including: a processor configured to generate a pre-distortion signal by compensating an input signal for a distortion based on a distortion compensation coefficient and a plurality of delayed signals obtained by delaying the input signal by a plurality of amounts of delay, and an amplifier configured to generate an amplified signal by amplifying the pre-distortion signal, wherein the processor calculates the distortion compensation coefficient based on the input signal, the pre-distortion signal, and the amplified signal, and calculates the plurality of amounts of delay based on the amplified signal.

Abstract: In a distortion compensating unit, a threshold calculating unit calculates a clip threshold to be set in an adjusting unit based on an address value generated by an address generating circuit. For example, the threshold calculating unit calculates the clip threshold by identifying the maximum value of address values generated by the address generating circuit in each adjustment unit period and subtracting a certain offset value from the identified maximum value. The adjusting unit adjusts a distortion compensation coefficient based on an address value received from the address generating circuit and a magnitude relationship with the set clip threshold.

Abstract: A delay quantity estimation apparatus comprises a first correlation value arithmetic unit to calculate a first correlation value as a correlation value between a first input signal and a feedback signal delayed with a first delay value; a second correlation value arithmetic unit to calculate a second correlation value as a correlation value between the first input signal and a feedback signal delayed with a second delay value; and a delay quantity estimation unit to estimate a delay quantity of the feedback signal with respect to the input signal on the basis of the first difference value as a difference between the first correlation value and the second correlation value, wherein the second delay value is a value given by adding a certain value to the first delay value.

Abstract: A distortion compensation device includes a storage unit, an address generator, and a distortion compensation processor. The storage unit stores therein a distortion compensation coefficient for compensating distortion generated in an amplifier for amplifying an input signal. The address generator generates a first address based on a power value of the signal at a current time. Furthermore, the address generator delays, every time a new augend is input, the sum of the power value of the signal at the current time and the augend. The address generator generates a second address based on the sum obtained by calculating a new augend, from the delayed sum. The distortion compensation processor acquires a distortion compensation coefficient corresponding to a combination of the first address and the second address from the storage unit and performs distortion compensation processing on the signal by using the acquired distortion compensation coefficient.

Abstract: A distortion compensation apparatus includes: a storage unit that stores a distortion compensation coefficient; a distortion-compensation-coefficient selecting unit that takes a logarithm of power of an input signal and exponentiates a value obtained by taking the logarithm, and that selects a distortion compensation coefficient that is stored in the storage unit according to a value obtained by the exponentiating; a distortion-compensation processing unit that acquires the selected distortion compensation coefficient from the storage unit, and that performs distortion compensation processing on the input signal to the distortion-compensation-coefficient selecting unit using the acquired distortion compensation coefficient; an amplifier that amplifies the signal subjected to the distortion compensation processing; and a distortion-compensation-coefficient updating unit that updates the distortion compensation coefficient stored in the storage unit based on the amplified signal and the input signal to the dist

Abstract: A distortion compensation apparatus for compensating distortion of an input signal by an amplifier, the apparatus including: a storage unit configured to store a distortion compensation coefficient; a distortion compensation processing unit configured to read the distortion compensation coefficient from the storage unit based on a plurality of first addresses each corresponding to power of the input signal and perform distortion compensation on the input signal; and a distortion compensation coefficient copy unit configured to store the distortion compensation coefficient stored at a third address to a second address in which no distortion compensation coefficient is stored, between a maximum address and a minimum address of the storage unit storing the distortion compensation coefficients out of plurality of first addresses.

Abstract: A distortion compensator compensates for distortion of a signal caused by an amplifier. A storage section stores a plurality of compensation coefficients used for distortion compensation. A selection section selects a compensation coefficient corresponding to an index value indicative of a power level of the signal from among the plurality of compensation coefficients. The selection section determines whether or not the power level is higher than a threshold, and uses, based on a determination result, a first index value calculated without using a logarithmic operation or a second index value calculated by using a logarithmic operation.

Abstract: A transmission apparatus includes a signal processing unit to perform a distortion compensation process on a transmitting signal based on a distortion compensation coefficient, and an updating unit to update a transmission power of the transmitting signal subjected to the distortion compensation process in certain processes, to transmit the transmitting signal at the updated transmission power. The signal processing unit may set a referring range of the distortion compensation coefficient stored in a storage unit, based on the transmitting signal before performing the distortion compensation process and the transmitting signal having the transmission power thereof updated by the updating unit.

Abstract: A wireless apparatus includes amplifying systems each including a storing unit storing a distortion compensation coefficient for compensation for a nonlinear distortion of one or more transmission signals, a compensator compensating for the nonlinear distortion using the distortion compensation coefficient stored in the storing unit, and an amplifier amplifying the transmission signal after distortion compensation.

Abstract: A distortion compensation amplifier device for compensating for distortion of a transmission signal generated by amplifying the transmission signal and for outputting the compensated transmission signal. The distortion compensation amplifier includes a storage unit that stores therein distortion compensation coefficients; a processor that performs distortion compensation processing on the transmission signal by using one of the distortion compensation coefficients; and an amplifier that amplifies the transmission signal that has been subjected to the distortion compensation processing; wherein the processor calculates an average value of the distortion compensation coefficients stored in the storage unit, and calculates the distortion compensation coefficient on the basis of the transmission signal, and the average value.