摘要:
A disclosed group delay characteristic correcting device corrects group delay characteristics of an analog low-pass filter used to remove aliasing of a digital-analog converter or an analog-digital converter. The group delay characteristic correcting device includes a digital signal processing unit configured to have an all-pass phase circuit at a stage previous to the digital-analog converter or at a stage subsequent to the analog-digital converter so as to correct the group delay characteristics of the analog low-pass filter.
摘要:
A disclosed group delay characteristic correcting device corrects group delay characteristics of an analog low-pass filter used to remove aliasing of a digital-analog converter or an analog-digital converter. The group delay characteristic correcting device includes a digital signal processing unit configured to have an all-pass phase circuit at a stage previous to the digital-analog converter or at a stage subsequent to the analog-digital converter so as to correct the group delay characteristics of the analog low-pass filter.
摘要:
A phase tracking circuit includes a divider part dividing an input signal that includes data sub-carriers and pilot sub-carriers into groups so that each of the groups includes at least one of the pilot sub-carriers, and a correcting part correcting phases of data sub-carriers of the input signal included in one of the groups on the basis of an amount of phase rotation of the at least one of the pilot sub-carriers included in the above one of the groups.
摘要:
A phase tracking circuit includes a divider part dividing an input signal that includes data sub-carriers and pilot sub-carriers into groups so that each of the groups includes at least one of the pilot sub-carriers, and a correcting part correcting phases of data sub-carriers of the input signal included in one of the groups on the basis of an amount of phase rotation of the at least one of the pilot sub-carriers included in the above one of the groups.
摘要:
In a wireless communication apparatus in a time division duplex system, a transmission signal generation unit generates a transmission signal. A power amplifying device amplifies the generated transmission signal. A control signal generation device generates a drain voltage control signal for control of the drain voltage of the power amplifying device, and a gate voltage control signal for control of the gate voltage of the power amplifying device. The switch unit switches off the drain power supply of the power amplifying device during reception in the time division duplex system according to the drain voltage control signal. In addition, the power amplifying device sets a higher gate voltage during reception in the time division duplex system higher than during transmission according to the gate voltage control signal.
摘要:
A radio communication system including a base station apparatus including a first memory to store a schedule for communication using each of a plurality of set values of a predetermined communication element in the physical layer, a first antenna to communicate with a terminal apparatus using a first set value of the plurality of set values in accordance with the schedule stored in the first memory, and a first processor to select a second set value of the plurality of set values if the condition of communication performed with the terminal apparatus by the first antenna using the first set value has deteriorated, and cause the first antenna to perform communication using the selected second set value in accordance with the schedule and the terminal apparatus including a second memory to store the schedule, a second antenna to communicate with the base station apparatus, and a second processor.
摘要:
A mobile communication terminal used in a mobile communication system providing mobile communicating service in a first frequency band is disclosed. The mobile communication terminal comprises a first signal processing circuit for processing signals for the mobile communication service; a second signal processing circuit for processing signals for radio tag communicating in a second frequency band; and an antenna commonly used by the first and second signal processing circuits. The impedance of the antenna is matched with the first signal processing circuit in the first frequency band and matched with the second signal processing circuit in the second frequency band.
摘要:
A wireless communications node, being included in a multi-hop route starting from a source node and terminating at a destination node, has a receiving part configured to receive signals including transmission data prepared by the source node and transferring the received signals to a succeeding node, a preparing part configured to prepare source node data including at least identification data of the source node based on a predetermined portion of the transmission data, and a reporting part configured to report the source node data and relay data to a management node that manages cost data of plural nodes included in an ad hoc network. The relay data include the cost data and station data including at least identification data of the wireless communications node.
摘要:
A wireless communications node, being included in a multi-hop route starting from a source node and terminating at a destination node, has a receiving part configured to receive signals including transmission data prepared by the source node and transferring the received signals to a succeeding node, a preparing part configured to prepare source node data including at least identification data of the source node based on a predetermined portion of the transmission data, and a reporting part configured to report the source node data and relay data to a management node that manages cost data of plural nodes included in an ad hoc network. The relay data include the cost data and station data including at least identification data of the wireless communications node.
摘要:
A MIMO wireless communication system and wireless communication apparatuses are disclosed that increase the practically usable communication channel capacity in the Shannon channel capacity that determines the ratio of maximum signal transmission speed to frequency. Each wireless communication apparatus includes antenna units that transmit and receive radio frequency signals, and a weight controlling unit that provides weights with respect to the antenna units. The antenna units are formed by adaptive array antenna units that can change the directivity by varying weights with respect to antenna elements. The weight controlling unit includes an eigenvalue calculating unit that calculates the eigenvalues of a matrix HH* (H being a channel matrix), an inverse calculation unit that calculates such a channel matrix H′ as to have all eigenvalues within a predetermined range that includes the average value of the calculated eigenvalues, and a directivity adjusting unit that adjusts the adaptive array antenna directivity so that the current channel matrix H approaches the calculated channel matrix H′.