Mitsubishi Denki Kabushiki Kaisha

Other

Mitsubishi Electric Corporation

Akihiro Shibuya

Takahisa Yamauchi

Noriyuki Fukui

Hideto Aikawa

Masaaki Kusano

Michiaki Takano

Tadashi Matsumoto

Youichi Moritani

Hiroshi Usami

Eimatsu Moriyama

Tetsuo Onodera

Kabushiki Kaisha

Kiyoshi Hamaguchi

Yoichi Saito

Ryouichi Fujie

Mitsuhiko Mizuno

A terminal transmits a request for a resource assignment to a base station, and acquires a value of a resource for data transmission. The terminal does not transmit the new data to the base station when the resource for data transmission does not exist, and transmits the new data to the base station otherwise, after acquiring the value. The terminal autonomously transmits, when the new data is transmitted to the base station and a NAK signal is received from the base station, the retransmission data to the base station without sending a transmission request to the base station for resources to transmit the retransmission data.

Communication method, terminal, and base station

In the timing correcting device, a RAKE path detecting circuitdetects a plurality of path candidates to be tracked, from a reception signal, and outputs a 'timing of a path' and a 'detection correlation value' corresponding to each path candidate, as a result of the detection. Next, each tracking-path candidate deciding circuit (, . . . ) generates a predetermined decision standard that is necessary for selecting an optimum path timing from timings of the path candidates, based on an individually allocated result of the detection. Further, the tracking-path selecting circuitselects a timing of an optimum path to be tracked, based on the result of the detection and the predetermined decision standards. Then, a comparator circuitcompares a predetermined reception reference timing given from the outside with the optimum path timing, and calculates a phase difference between the two. Last, the timing correction control circuitcontrols a clock based on the phase difference, thereby to correct the reception reference timing.

Timing correcting device and timing correcting method

A transmitting station receives, from one of receiving-stations to which it has been assigned a communication channel, a retransmission request indicating retransmission of a particular frame, switches the communication with the one receiving station to a communication according to an SAW (Stop and Wait) scheme, retransmits the particular frame according to the SAW scheme to the one receiving station, assigns the communication channel that was assigned to the one receiving station another receiving station, and switches the communication with the one receiving station to the successive transmission upon reception from the one receiving station of a reply indicative of correct reception of the particular frame.

Communication method, communication system and communication apparatus

A control unit measures a phase error between a reference timing of a mobile station and a reception timing from a base station based on reception data from a reception unit and a count from a reference timing counter unit, determines a frequency deviation correction value calculation period corresponding to the measured phase error, and outputs it to a frequency deviation correction value calculation unit. The frequency deviation correction value calculation unit does not calculate a deviation at every reception time when intermittent reception is repeated, but calculates a deviation at intervals following the frequency deviation correction value calculation period given from the control unit.

Timing control device and timing control method

A radio communication apparatus includes a low-rate clock oscillator for generating a low-rate clock signal used for reception timing estimation; a frequency deviation measuring duration controller for determining a deviation measuring duration of measuring a frequency deviation of the low-rate clock signal in accordance with an intermittent time interval of the radio signal; a frequency deviation measuring section for measuring the frequency deviation of the low-rate clock signal over the deviation measuring duration; and a timing counter for correcting the frequency deviation of the low-rate clock signal, for measuring an intermittent span of the received signal in response to the low-rate clock signal after the correction, and for generating the estimated reception timing of the radio signal.

Radio communication apparatus and its reception timing estimating method

The present invention is directed to a TDMA communication system which is adapted to different communication environments or prepares different communication environments and allows each mobile station to be set for working in any one of the different communication environments. The communication system commonly uses a TDMA format that has a fixed frame-length and a constant number of bits for each of the slots composing the frame. The communication environments have prepared respective sets of communication conditions, each set including a transmission power, a modulating method, the number of multiplexed signals, error-correction, an antenna gain, a frequency hopping value and a diversity value. At each mobile station and each base station, one of plural sets of communication conditions for respective environments is selected to establish communication with each other under the selected environment.

Time-division multiple-access communication system

A mobile communication system which comprises a base station and a mobile station that communicates therewith while performing frequency hopping based on a predetermined hopping sequence. Based on the received power of a signal received from the base station at a first frequency in the hopping sequence, the mobile station switches the first frequency to a second one next thereto in the hopping sequence and keeps on communicating with the base station at the second frequency.

Mobile communication system

A radio communication apparatus capable of solving a problem involved in a conventional apparatus in that in addition to a first receiver, a second receiver must be provided for establishing synchronization with a contiguous base station, which causes an increase in a circuit scale and consumed power of a mobile station. The present radio communication apparatus switches, when carrying out handoff from the current base station to a contiguous base station, a receiving frequency of a receiver from the frequency of the current base station to that of the contiguous base station, and a counter to be corrected by a synchronization manager from a first counter to a second counter that is used to establish synchronization with the contiguous base station.

Growing community of inventors

Tokyo, Japan

Akihiro Shibuya