Hitachi, Ltd.

Renesas Technology Corp.

Hiroshi Nogami

Toshihito Habuka

Toyokazu Hori

Naoto Inokawa

Makoto Miyamoto

Tatsuji Matsuura

Masaki Noda

Yukio Fukui

Kazuaki Hori

Masaji Ishigaki

Norio Goto

Kazuyuki Takada

Jun Tozawa

Tetsuya Shibayama

Tomohiro Kataoka

Hiroshi Fujio

The invention comprises: processing for receiving an OFDM packet having a preamble and the following data transmission symbol, in which packet the subcarrier interval of the preamble is set wider than that of the data transmission symbol; processing for estimating a DC offset occurring at a receiving side by using the received preamble; processing for correcting the DC offset on the received data transmission symbol, according to the estimation result of the DC offset; and processing for demodulating the DC offset corrected data transmission symbol. Thus, it is possible to estimate a DC offset and then correct the DC offset according to the estimated value, in the OFDM packet with no nul symbol defined there.

OFDM demodulation method and semiconductor integrated circuit device

Disclosed herein is an encryption and decryption communication semiconductor device comprising at least, a communication interface for performing a transfer of data according to a predetermined communication system, one or two or more encryption/decryption circuits which encrypt or decrypt input data in accordance with a predetermined algorithm, and a plurality of external interfaces for performing the input/output of data from and to external devices. The communication interface, the encryption/decryption circuits and the plurality of external interfaces are formed on one semiconductor chip. In the cryption and decryption communication semiconductor device, input data sent from any one of the plurality of external interfaces is encrypted or decrypted by at least one of the encryption/decryption circuits and is capable of being outputted to any different one of the plurality of external interfaces.

Encryption and decryption communication semiconductor device and recording/reproducing apparatus

A wireless LAN system has auto gain control with no work load applied to its baseband processing block. When the wireless LAN system gets ready to receive a signal, the gain control circuit switches between the receiving antennas. The gain control circuit sets gain setting value time divisional data according to the level of a received signal to roughly control the gain to be set in the LAN and the gain to be set in two programmable gain amplifiers.

Semiconductor integrated circuit device, wireless LAN system, and auto gain control system

A phase change optical disk in which the thermal conductivity of a first region at an outer peripheral position of the disk is set at a value larger than the minimum value of that of a second region. In the optical disk, in order to provide an output characteristic of a uniform reproduced signal when the disk is rotated at a fixed rotation speed, toward an outer peripheral position thereof, the critical cooling rate of a recording film is set at a larger value or the temperature which the recording film is to reach is set at a lower value. Provided is a method of using the phase change optical disk for recording or erasing information, in which method, the power of the laser beam to be directed to an inner peripheral position of the disk is set larger than that directed to an outer peripheral position thereof.

Phase change optical disk and method for using the same

Growing community of inventors

Fujisawa, Japan

Hiroshi Nogami