Nippon Hoso' Kyokai

Nec Corporation

Kazuyoshi Shogen

Shoji Tanaka

Yoichi Suzuki

Akinori Hashimoto

Hisashi Sujikai

Noboru Toyama

Tomoki Obuchi

Seiichi Yamawaki

To provide a digital data transmitting apparatus and a digital data receiving apparatus that can realize, even when a transmission channel characteristic changes because of aged deterioration or the like of a relay, improvement of a reception performance following the change. A transmitting apparatusgenerates a multiplexing frame formed by N slots including control information, data, outer parities, stuff bits, and inner parities and added with synchronization, pilot, and a transmission control signal and a parity and transmits data of the respective slots in a transmission system designated by the transmission control signal. In this case, pilot signals are symbols allocated to all signal points in order determined in advance for each of modulation schemes. A receiving apparatusrewrites a phase error tableto calculate a phase error and performs synchronous detection according to the pilot signals. The receiving apparatusalso rewrites a likelihood tableto perform inner code decoding. Consequently, since reception processing adapted to distortion of a transmission channel characteristic can be performed, improvement of a reception performance can be realized.

Digital data transmitting device and digital data receiving device

Digital data transmitting apparatus and digital data receiving apparatus

A corrugated elliptical waveguide medium comprises a corrugated hybrid mode excitation member having an elliptical transverse cross-section for propagating electromagnetic energy therethrough. The excitation member is provided with longitudinally spaced apart parallel corrugations with the teeth of the corrugations defining an inner ellipse and the grooves of the corrugations defining an outer ellipse. The depths of the corrugation grooves on the major and minor axes of the ellipsis are dimensioned such that the tangential electric and magnetic field components of the energy in a circumferential direction are zero on the inner ellipse.

Corrugated elliptical waveguide or horn

Growing community of inventors

Tokyo, Japan

Kazuyoshi Shogen