Nec Corporation

Nec Home Electronics, Inc.

Nec Corportion

Soichi Tsumura

Kojiro Hamabe

Mariko Matsumoto

Nahoko Takano

Akira Inoue

Takayuki Nagai

Takeshi Kondo

Yukitsuna Furuya

Kaoru Endo

Toshio Asai

Naomichi Takahashi

Susumu Okuyama

Provided are an information distribution device, system, program, and method that can increase the effectiveness of advertisements. The information distribution device selects advertisements to distribute based on viewer attributes collected while distributing content to a display unit.

Information distribution device, information reception device, system, program, and method

Pluralities of state update frames are defined. The base station is configured to transmit a state update data to instruct the mobile station to be set to either an active state or a suspended state, in the state update frames. The base station is configured to transmit a packet only to the mobile station that has been set to the active state by the state update data. The base station notifies the mobile station of a packet transmission by transmitting a control data including a data necessary to receive the packet, earlier than the packet transmission by a predetermined time. The mobile station is configured to receive the control data and the packet when being set to the active state, and is configured to not receive the control data and the packet when being set to the suspended state.

System and method for mobile communication

There is provided a mobile communication system capable of reducing the power consumption in the packet wait state and promptly transmitting a packet when data transmission is requested. At a predetermined synchronization establishment interval start time (T), a base station starts transmission of DPCH (DL) which is a downlink individual channel. A mobile station receives the DPCH (DL) and starts synchronization establishment operation. If the synchronization of the DPCH (DL) is not established by the synchronization establishment interval end time (T), the synchronization establishment operation is continued. If the base station cannot detect transmission of the DPCH (UL) which is an uplink individual channel from the base station by the synchronization establishment interval end time (T), the base station continues transmission of the DPCH (DL) to the mobile station and suspends user data transmission in the state update information to the mobile station and DPCH (DL) to the mobile station and control signal transmission to an upper node layer until the DPCH (UL) transmission is detected.

Synchronization establishment between a mobile station and base station system and method used for them

A mobile communication system includes a base station and a mobile station. The base station includes a transmitting/receiving section that transmits/receives a packet to/from the mobile station. The base station also includes a base station state updating section that notifies the mobile station of transmission/reception state update information that indicates update of a packet receivable state in the mobile station. The mobile station includes a mobile station transmitting/receiving section that transmits/receives the packet to/from the base station. The mobile station also includes a mobile station state updating section that sets, on the basis of the transmission/reception state update information, one of an active state in which the control information for packet transmission can be received and a suspend state in which the control information for packet transmission cannot be received.

Mobile communication system, mobile station, base station, and packet communication method used therefor

There is provided a mobile radio communication system which is capable of reducing a group ID in length with respect to the number of mobile stations and realizing efficiency of air resources. Suspend control of mobile stations is performed by notifying not only control information but also transmission/reception state update information for instructing a state [Active/Suspend] in a status update frame set in advance from a base station to the mobile stations using an HS-SCCH. The base station performs the suspend control by sending, in state update information at timing of a state update frame number of a user ID allocated in advance, a group ID of a user ID allocated to mobile stations desired to be made Active in advance.

Mobile radio communication system and base station, and mobile radio communication method used therefor

In an interpolation synchronous detection method in a radio communication system in which a pilot symbol whose phase point is known is periodically inserted in an information signal to allow interpolation synchronous detection on a receiving side, synchronous detection of the information between the pilot symbols is performed by linearly interpolating a transfer function estimated from the pilot symbols respectively located before and after the information signal, and a reception sampling point timing used for the synchronous detection is updated at the middle point between the pilot symbols respectively located before and after the information signal. A radio communication system is also disclosed.

Interpolation synchronous detection method and radio communication system

A process of assigning frequencies uses propagation loss in a CDMA communication system. A base station measures propagation loss over a channel between the base station and a mobile station. If the measured propagation loss is greater than a certain fixed value, the base station determines that since the mobile station is present in a position distant from the base station, the mobile station may possibly interfere with a base station of another CDMA communication system. The base station assigns a frequency channel which is not adjacent to the frequency band assigned to the other CDMA communication system to the mobile station.

Method of assigning frequency using propagation loss

A frame timing synchronization method of establishing frame synchronization includes the steps of obtaining an integration result, a plurality of number of times, by integrating the square of a complex reception sample from an arbitrary integration start point while shifting an integration range at predetermined intervals, making a search for the maximum integration result from the plurality of integration results, demodulating (despreading) complex reception samples included in a predetermined range having an integration start point as a center corresponding to the maximum integration result while setting the respective samples as demodulation (despreading) start points, and establishing frame synchronization by detecting the portion modulated (spread) by BPSK from the obtained demodulation (despreading) results.

Frame timing synchronization method

A correlator can stop correlation computation on the basis of the value of a despreading code, and decreases the operation ratio of a section operated in accordance with a despreading code pattern to &frac12; that of a conventional scheme (when spreading is performed by BPSK). This correlator reduces the current consumption to about &frac12; that of the conventional scheme (when spreading is performed by BPSK) in a case of a sufficiently high spreading ratio by using a common total adder regardless of the despreading code pattern, thereby realizing lower current consumption than the conventional correlator without decreasing the operation speed.

Correlator for realizing low current consumption

A rate matching method allowing reliable digital communication is disclosed. After setting D&equals;&verbar;n&minus;m&verbar; and Q&equals;n/D, the input symbol string is sequentially divided to produce D symbol strings each consisting of either Q symbols or (Q&plus;1) symbols so as to arrange the input symbols in an arrangement of columns (C) and rows (R). Then, after selecting a single symbol located at a predetermined position for each of the D symbol strings, the output symbol string is provided by deleting the single symbol for each of the D symbol strings when n>m or repeating the single symbol for each of the D symbol strings when n<m.

Rate matching method

In a CDMA receiver for intermittently receiving a spread spectrum received signal using a despreading code and comprising a high-resolution time reference generating section and a low-resolution time reference generating section, a state control section puts, for substantially a reception operation stop time interval, the CDMA receiver into a cold standby state where the high-resolution time reference generating section does not operate while the low-resolution time reference generating section operates. On or immediately before a reception return time instant, the state control section puts the CDMA receiver into a hot standby state where the high-resolution time reference generating section operates.

CDMA receiver comprising a synchronous timing notifying section capable of reaching low consumption of current

A CDMA receiver with a reduced number of high speed adders is provided, wherein integration for one symbol period is performed for each value of spreading code corresponding to a particular user signal by the use of a high speed adder, first and second switches, and a register group. The integrated values are stored in respective first registers of the register group and then despread in accordance with respective spreading codes. As a result, an adder with a slow operational speed can be employed as a first slow speed adder that adds the values from first multipliers, and a second slow speed adder for addition of the values of the first registers. Therefore, a common pilot signal and a user signal can be despread with only one high speed adder.

CDMA receiver with a reduced number of required high speed adders

In a radio apparatus including a plurality of variable-gain amplifiers and at least one frequency converter which are connected in series, a gain controller includes a plurality of gain control lines and a gain control signal generator. The gain control lines are connected to the variable-gain amplifiers, respectively. The gain control signal generator individually generates a plurality of gain control signals which are supplied to the variable-gain amplifiers through the gain control lines, respectively.

Automatic gain control system and method of automatic gain control

A radio apparatus includes a first variable-gain circuit, a second variable-gain circuit, and a demodulator, wherein a band-pass filter is provided between the first and second variable-gain circuits and the demodulator inputs an output of the second variable-gain circuit. An error occurrence probability is detected from an output of the demodulator and a signal level is detected from the output of the second variable-gain circuit. A received signal strength is estimated from the signal level of the output of the second variable-gain circuit using an aggregate gain from the first variable-gain circuit to the second variable-gain circuit, and then the respective first and second gains of the first and second variable-gain circuits are changed in opposite directions depending on the error occurrence probability and the estimated received signal strength.

Method and apparatus using first and second variable gain control

A digital temperature compensation oscillator by which its AFC operation to a receive signal cannot be disturbed by temperature compensation operation. A digital temperature compensation oscillator comprises a temperature sensor, an address creating section, a ROM, latching means, and a voltage-controlled crystal oscillator. The temperature sensor produces an output signal varied according to ambient temperatures. The address creating section converts an output from the temperature sensor into a signal and then creating it as a ROM (read-only memory) address. The ROM stores a control voltage to compensate a frequency variation due to ambient temperatures of a voltage-controlled crystal oscillator. The latching means holds or passes data output from the ROM according to an external control signal. The D/A converter produces a control voltage for the voltage-controlled crystal oscillator according to the latching means. The voltage controlled crystal oscillator is fine adjusted based on two control voltages including the output signal from the D/A converter and an external analog AFC signal.

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Tokyo, Japan

Soichi Tsumura