Abstract: According to the embodiments, a satellite signal acquiring apparatus includes an antenna, a direction sensor, a position sensor and a processor. The antenna receives radio waves from satellites. The direction sensor obtains direction information. The position sensor obtains position information. The processor directs the antenna based on the direction information obtained by the direction sensor to search a search range including a satellite target angle that is associated with the position information obtained by the position sensor for the satellite. The processor calculates a level of reliability of the direction information obtained by the direction sensor. The processor narrows the search range in accordance with the level of reliability.

Abstract: According to the embodiments, a satellite signal acquiring apparatus includes an antenna, a direction sensor, a position sensor and a processor. The antenna receives radio waves from satellites. The direction sensor obtains direction information. The position sensor obtains position information. The processor directs the antenna based on the direction information obtained by the direction sensor to search a search range including a satellite target angle that is associated with the position information obtained by the position sensor for the satellite. The processor calculates a level of reliability of the direction information obtained by the direction sensor. The processor narrows the search range in accordance with the level of reliability.

Abstract: An optical communication system includes an optical transmission apparatus and an optical receiving apparatus. The optical transmission apparatus includes an input port to receive an electric signal, a noise generator to generate noise, a transmission signal generator to generate a transmission signal by multiplexing the noise with the electric signal, and an electric/optical converter to convert the transmission signal into an optical signal and send out the optical signal to an optical transmission path. The optical receiving apparatus connected to the optical transmission apparatus via the optical transmission path and receiving the optical signal through the optical transmission path. The optical receiving apparatus includes an optical/electric converter to convert the optical signal received through the optical transmission path into a receive electric signal and a receiving filter to remove the noise from the receive electric signal.

Abstract: An optical communication system includes an optical transmission apparatus and an optical receiving apparatus. The optical transmission apparatus includes an input port to receive an electric signal, a noise generator to generate noise, a transmission signal generator to generate a transmission signal by multiplexing the noise with the electric signal, and an electric/optical converter to convert the transmission signal into an optical signal and send out the optical signal to an optical transmission path. The optical receiving apparatus connected to the optical transmission apparatus via the optical transmission path and receiving the optical signal through the optical transmission path. The optical receiving apparatus includes an optical/electric converter to convert the optical signal received through the optical transmission path into a receive electric signal and a receiving filter to remove the noise from the receive electric signal.

Abstract: An optical communication system includes an optical transmission apparatus and an optical receiving apparatus. The optical transmission apparatus includes an input port to receive an electric signal, a noise generator to generate noise, a transmission signal generator to generate a transmission signal by multiplexing the noise with the electric signal, and an electric/optical converter to convert the transmission signal into an optical signal and send out the optical signal to an optical transmission path. The optical receiving apparatus connected to the optical transmission apparatus via the optical transmission path and receiving the optical signal through the optical transmission path. The optical receiving apparatus includes an optical/electric converter to convert the optical signal received through the optical transmission path into a receive electric signal and a receiving filter to remove the noise from the receive electric signal.