Nec Corporation

Kosuke Naito

Motoya Iwasaki

Tadashi Ogami

Syuji Yamaguchi

A device performs demodulation of control signals from multiple radio terminals, based on the correlations in the frequency domain between a predetermined code and the orthogonalized control signals and reference signals of the multiple radio terminals obtained by cyclic shifts of the predetermined code. The device includes: a demultiplexer which demultiplexes a reference signal component and a control signal component based on a correlation profile; a path detector which detects a path location or path locations for each radio terminal based on the power values of the reference signal components; extractor which extracts the correlation values of the reference signal components and the correlation values of the control signal components, respectively; and RAKE combiner which combines the extracted values.

Device and method for demodulating control signals

This invention relates to a portable information terminal having a plurality of functions such as a radio communication terminal unit, a data processing terminal unit, a digital camera unit, etc. The portable information terminal comprises a plurality of function processing units which respectively perform the functions; a battery which supplies electric power to the function processing units; a remaining battery charge detecting unit which detects remaining battery charge of the battery; and a power supply control unit. This power supply control unit compares the remaining battery charge with each of power supply limiting values determined in advance with respect to the function processing units, and, when the remaining battery charge becomes lower than at least one of the power supply limiting values of the function processing units, the power supply control unit stops power supply to the at least one of the function processing units and/or outputs warning signals.

Portable information terminal and power supply control method therefor

A multicast message communicating system is disclosed, that comprises a base station for transmitting a multicast message using a multicast channel, and a plurality of mobile stations for receiving the multicast message from the base station, wherein the base station has a receiving portion for receiving transmission power increase request signals from the plurality of mobile stations corresponding to reception powers of the multicast message received from the plurality of mobile stations, a reception power detecting portion for detecting the reception powers of the transmission power increase request signals received from the receiving portion, a transmission power control generating means for deciding and generating a transmission power increase request signal or a transmission power decrease request signal for the plurality of mobile stations corresponding to the received powers.

Multicast message communicating method, multicast message communicating system, base station thereof, and mobile station thereof

A multi-user parallel interference canceler apparatus for repeatedly performing a hard decision over a plurality of stages to improve channel estimation precision, includes a plurality of interference estimation units, a plurality of decision error estimation units, a plurality of combiners, and a plurality of receivers. The interference estimation units are arranged in units of stages and the number of estimation units in each stage corresponds to the number of users. The decision error estimation units are arranged in units of stages. The combiners are arranged in units of stages. The receivers are arranged in a last stage in units of users.

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Tokyo, Japan

Kosuke Naito