It is shown that, particularly for terrestrial cellular telephony, the interference-suppression feature of CDMA (code division multiple access) can result in a many-fold increase in capacity over analog and even over competing digital techniques. A single-cell system, such as a hubbed satellite network, is addressed, and the basic expression for capacity is developed. The corresponding expressions for a multiple-cell system are derived. and the distribution on the number of users supportable per cell is determined. It is concluded that properly augmented and power-controlled multiple-cell CDMA promises a quantum increase in current cellular capacity. >

On the capacity of a cellular CDMA system

In a data communication system capable of variable rate transmission, high rate packet data transmission improves utilization of the forward link and decreases the transmission delay. Data transmission on the forward link is time multiplexed and the base station transmits at the highest data rate supported by the forward link at each time slot to one mobile station. The data rate is determined by the largest C/I measurement of the forward link signals as measured at the mobile station. Upon determination of a data packet received in error, the mobile station transmits a NACK message back to the base station. The NACK message results in retransmission of the data packet received in error. The data packets can be transmitted out of sequence by the use of sequence number to identify each data unit within the data packets.

Method and apparatus for high-rate packet data transmission

A multiple-access MIMO WLAN system that employs MIMO, OFDM, and TDD. The system (1) uses a channel structure with a number of configurable transport channels, (2) supports multiple rates and transmission modes, which are configurable based on channel conditions and user terminal capabilities, (3) employs a pilot structure with several types of pilot (e.g., beacon, MIMO, steered reference, and carrier pilots) for different functions, (4) implements rate, timing, and power control loops for proper system operation, and (5) employs random access for system access by the user terminals, fast acknowledgment, and quick resource assignments. Calibration may be performed to account for differences in the frequency responses of transmit/receive chains at the access point and user terminals. The spatial processing may then be simplified by taking advantage of the reciprocal nature of the downlink and uplink and the calibration.

MIMO WLAN system

A gesture recognition method includes detecting multiple pointers in close proximity to a touch surface to determine if the multiple pointers are being used to perform a known gesture. When the multiple pointers are being used to perform a known gesture, executing a command associated with the gesture. A touch system incorporating the gesture recognition method is also provided.

Gesture recognition method and touch system incorporating the same

Techniques to implement MBMS services in a wireless communication system. In one aspect, a method is provided for processing data for transmission to a plurality of terminals. Frames of information bits (which may have variable rates) are provided to a buffer implementing a matrix. The matrix is padded with padding bits based on a particular padding scheme to support variable frame rates. The frames are then coded based on a particular block code to provide parity bits. The frame of information bits and the parity bits are then transmitted to the terminals. In another aspect, a method is provided for controlling the transmit power of a data transmission to a plurality of terminals. In accordance with the method, TPC streams are received from the terminals and processed to obtain a stream of joint power control commands used to adjust the transmit power of the data transmission.

Multi-media broadcast and multicast service (MBMS) in a wireless communication system

In a spread spectrum communication system, one (W.sub.n) of a series of orthogonal codes for spectrum spreading is assigned to signal-to-noise ratio measurement in a terminal. On the basis of a noise signal detected by de-spreading a signal received from an antenna with the above described orthogonal code (W.sub.n) and a pilot signal, each terminal derives a signal-to-noise ratio. Each terminal transmits the signal-to-noise ratio to the base station as a power control signal. On the basis of signal-to-noise information received from each terminal as the power control signal, the base station controls signal transmission power for each terminal.

Spread spectrum communication system and transmission power control method therefor

A communication system having an excellent communication path capacity characteristic even in an insight transmission environment in which a transmitter and a receiver can see each other directly in an MIMO communication system and a wireless communication device for the communication system, including: a wireless device having a transmitter for distributing transmission data including encoded data and a training signal to a plurality of antennas, and transmitting the data as radio signals from the plurality of antennas at a predetermined timing; a plurality of wireless devices having repeaters each for receiving the radio signal, storing the radio signal into a buffer so that the radio signal is delayed by predetermined time, and transmitting the radio signal delayed; and a wireless device having a receiver for receiving the radio signals from the plurality of second wireless devices by a plurality of antennas and demodulating the encoded data by using the training signal multiplexed on the received radio signal. Each wireless device determines whether relaying operation is necessary or not and transmits a control signal for controlling the relaying operation.

Multi point wireless transmission repeater system and wireless equipments

An electronic blackboard system with a PDP for displaying characters and images. A touch input device with a touch panel surface is provided on the front surface of the PDP. A printer outputs image data onto recording paper. A computer provides control over displays on the PDP as well over the printing operations of the printer according to the input from the touch input device. A frame unit has a board section for holding a display surface and a write-in surface of the electronic blackboard at a specified height. A printer accommodating section accommodates the printer and a computer accommodating section accommodates the computer therein. The computer accommodating section, the printer accommodating section and the board section are arranged in the vertical direction starting from the bottom.

Electronic blackboard system

The document information management system according to the present invention includes a hypertext preparing unit for preparing a hypertext. A file unit storing therein correlated information files. A medium form information preparing unit for prepares a medium for information from information in the hypertext. A medium form output unit outputs the recording paper as a medium form. A selection information adding unit adds selection information. A reader reads the selection information and linkage information from the medium form. A retrieving unit retrieves an appropriate correlated information file, and an output unit for outputs the correlated information file retrieved by the retrieving unit.

Generating and storing a link correlation table in hypertext documents at the time of storage

A radio communication system having a base station and a plurality of radio terminals, wherein each radio terminal having a transmission request transmits a reservation packet at arbitrary timing through a reservation channel in accordance with a CDMA scheme, and the base station assigns a traffic channel and a time slot to be used to each radio terminal requesting a reservation through a reply packet outputted onto a reply channel. On the reservation channel, a short spreading code corresponding to a matched filter is applied.

Takashi Yano

Papers

Spread spectrum communication system and transmission power control method therefor

Multi point wireless transmission repeater system and wireless equipments

Electronic blackboard system

Generating and storing a link correlation table in hypertext documents at the time of storage

CDMA mobile communication system and communication method