Abstract: A mobile radio device capable of receiving a radio signal whose frequency band switches, includes a setting unit that when the frequency band of the radio signal is a first frequency band, sets a first threshold corresponding to the first frequency band, and that when the frequency band switches from the first frequency band to a second frequency band different from the first frequency band, sets for a given period, a third threshold that is between the first threshold and a second threshold corresponding to the second frequency band and subsequently sets the second threshold; and a determining unit that determines a travel speed of the mobile radio device, based on a comparison of a moving average obtained by temporally accumulating variations of estimates of propagation characteristics of the radio signal and averaging the accumulated variations by a moving average method using a threshold set by the setting unit.

Abstract: A mobile terminal communicating with a plurality of cells, including a serving cell, has a control unit. The control unit performs at least one control of (a) a first control for causing a path search unit to detect a path for the serving cell more preferentially than paths for cells other than the serving cell, (b) a second control for causing a finger assignment unit to assign a path detected for the serving cell preferentially over paths detected for cells other than the serving cell to a plurality of fingers, and (c) a third control for causing a reference frequency adjustment unit to adjust reference frequency so that the reference frequency is approximated to reference frequency of a base station controlling the serving cell.

Abstract: A mobile terminal has a communication unit for performing wireless communication, a plurality of modem units for performing modulation and demodulation in different communication methods, respectively, and a control unit for obtaining time information indicating a suspension of a wireless communication from a main modem unit in the plurality of modem units, for suspending the main modem unit from performing wireless communication via the communication unit, and for enabling the main modem unit to perform wireless communication via the communication unit on the basis of the time information, wherein, while the main modem unit suspending wireless communication, the control unit enables a sub modem unit in the plurality of modem units to measure a reception level via the communication unit in accordance with the obtained time information.

Abstract: A mobile radio device capable of receiving a radio signal whose frequency band switches, includes a setting unit that when the frequency band of the radio signal is a first frequency band, sets a first threshold corresponding to the first frequency band, and that when the frequency band switches from the first frequency band to a second frequency band different from the first frequency band, sets for a given period, a third threshold that is between the first threshold and a second threshold corresponding to the second frequency band and subsequently sets the second threshold; and a determining unit that determines a travel speed of the mobile radio device, based on a comparison of a moving average obtained by temporally accumulating variations of estimates of propagation characteristics of the radio signal and averaging the accumulated variations by a moving average method using a threshold set by the setting unit.

Abstract: A communication system includes: a base station; and a mobile terminal for sequentially sending a plurality of data packets at a designated data transfer rate and information of velocity of the mobile terminal to the base station; the base station including: a receiver for receiving the data packet and the velocity information; a transmitter for transmitting a request to the mobile terminal to resend a data packet upon detection of an error in the data packet previously received; and a reply controller for setting number of requests to be repetitively sent in accordance with the velocity information and, after the number of requests have been sent, sending command to change the designated data transfer rate to the mobile terminal.

Abstract: A mobile terminal communicating with a plurality of cells, including a serving cell, has a control unit. The control unit performs at least one control of (a) a first control for causing a path search unit to detect a path for the serving cell more preferentially than paths for cells other than the serving cell, (b) a second control for causing a finger assignment unit to assign a path detected for the serving cell preferentially over paths detected for cells other than the serving cell to a plurality of fingers, and (c) a third control for causing a reference frequency adjustment unit to adjust reference frequency so that the reference frequency is approximated to reference frequency of a base station controlling the serving cell.

Abstract: A mobile terminal has a communication unit for performing wireless communication, a plurality of modem units for performing modulation and demodulation in different communication methods, respectively, and a control unit for obtaining time information indicating a suspension of a wireless communication from a main modem unit in the plurality of modem units, for suspending the main modem unit from performing wireless communication via the communication unit, and for enabling the main modem unit to perform wireless communication via the communication unit on the basis of the time information, wherein, while the main modem unit suspending wireless communication, the control unit enables a sub modem unit in the plurality of modem units to measure a reception level via the communication unit in accordance with the obtained time information.

Abstract: A communication system includes: a base station; and a mobile terminal for sequentially sending a plurality of data packets at a designated data transfer rate and information of velocity of the mobile terminal to the base station; the base station including: a receiver for receiving the data packet and the velocity information; a transmitter for transmitting a request to the mobile terminal to resend a data packet upon detection of an error in the data packet previously received; and a reply controller for setting number of requests to be repetitively sent in accordance with the velocity information and, after the number of requests have been sent, sending command to change the designated data transfer rate to the mobile terminal.

Abstract: By providing a interference power estimation unit obtaining the power of interference in a common pilot signal with ten symbols in one slot and outputting the power of interference as the estimate of the amount of interference in the data signal's pilot signal and a signal-to-interference power ratio calculation unit calculating a signal-to-interference power ratio (SIR) using an output of the interference power estimation unit, in a spread spectrum communication method, a correct SIR can be estimated even when the number of symbols of an individual pilot signal in the slot of the data channel is small.

Abstract: Disclosed is a synchronization tracking circuit for synchronizing the phase of a despreading code sequence on a receiving side to the phase of a spreading code sequence on a transmitting side. The synchronization tracking circuit has a DLL circuit for performing synchronization tracking by DLL (Delay Locked Loop) control, and an interference-component estimation unit for estimating an interference component inflicted by another path upon a prescribed path of interest among multiple paths. The DLL circuit, which has an interference elimination unit, executes DLL control based upon a signal from which the interference component from the other path has been eliminated and causes the phase of the despreading code sequence on the receiving side to be synchronized with and track the phase of the spreading code on the transmitting side.

Abstract: By providing a interference power estimation unit obtaining the power of interference in a common pilot signal with ten symbols in one slot and outputting the power of interference as the estimate of the amount of interference in the data signal's pilot signal and a signal-to-interference power ratio calculation unit calculating a signal-to-interference power ratio (SIR) using an output of the interference power estimation unit, in a spread spectrum communication method, a correct SIR can be estimated even when the number of symbols of an individual pilot signal in the slot of the data channel is small.

Abstract: Disclosed is a synchronization tracking circuit for synchronizing the phase of a despreading code sequence on a receiving side to the phase of a spreading code sequence on a transmitting side. The synchronization tracking circuit has a DLL circuit for performing synchronization tracking by DLL (Delay Locked Loop) control, and an interference-component estimation unit for estimating an interference component inflicted by another path upon a prescribed path of interest among multiple paths. The DLL circuit, which has an interference elimination unit, executes DLL control based upon a signal from which the interference component from the other path has been eliminated and causes the phase of the despreading code sequence on the receiving side to be synchronized with and track the phase of the spreading code on the transmitting side.