Abstract: An image blurring correction apparatus includes: an optical system that forms a subject image on an image formation plane; an acceleration sensor that detects an acceleration of an apparatus that has the image formation plane; a first calculation circuit that calculates a first state quantity by using the acceleration; a second calculation circuit that calculates, as a second state quantity, an estimate value obtained by estimating a true value of the first state quantity by using the first state quantity and a model; and a third calculation circuit that calculates an amount of image blurring on the image formation plane by using the second state quantity.

Abstract: An image blurring correction apparatus includes: an optical system that forms a subject image on an image formation plane; an acceleration sensor that detects an acceleration of an apparatus that has the image formation plane; a first calculation circuit that calculates a first state quantity by using the acceleration; a second calculation circuit that calculates, as a second state quantity, an estimate value obtained by estimating a true value of the first state quantity by using the first state quantity and a model; and a third calculation circuit that calculates an amount of image blurring on the image formation plane by using the second state quantity.

Abstract: In a transmitting section, a modulator modulates a first carrier with data o be transmitted, thereby producing a modulated output f.sub.m, a local oscillator generates a local oscillating signal to be used as a second carrier f.sub.LO, a mixer mixes the modulated output and the local oscillating signal, thereby generating waves of different frequencies. These waves include an upper side band wave f.sub.LO +f.sub.m and a lower side band wave f.sub.LO -f.sub.m. A transmitting antenna radiates electromagnetic waves into the air, which includes the waves of different frequencies generated by the mixer. In a receiving section, a receiving antenna receives the electromagnetic waves, a diversity section extracts at least one of the upper side band and lower side band waves f.sub.LO +f.sub.m, f.sub.LO -f.sub.

Abstract: According to this invention, a modulator modulates a carrier serving as a fundamental wave with data to be transmitted, thereby to generate a modulated output including at least the fundamental wave and double wave thereof. A transmitting antenna radiates electromagnetic waves into the air, and the electromagnetic waves include the fundamental wave and the double wave included in the modulated output generated by the modulator. A receiving antenna receives the electromagnetic waves including the fundamental wave and the double wave radiated from the transmitting antenna. A diversity section generates an output having a diversity effect on the basis of the fundamental wave and the double wave included in the electromagnetic waves received by the receiving antenna. A demodulator demodulates the output having the diversity effect and generated by the diversity section, thereby to output data corresponding to the data to be transmitted.

Abstract: In a space-division multiplex communication method of executing multiplex communication according to this invention, a plurality of radio beams a--a' to d--d' radiated at same frequency in different directions and rotated at same rotational angular speed .omega. are independently received in synchronism with the rotational angular speed .omega. by a plurality of communication terminals R1 to R3 arranged at arbitrary positions in a space where the radio beams can be received, thereby realizing unidirectional multiplex communication using the same frequency. Interstation bidirectional multiplex communication is performed by introducing a frequency-division system to the communication terminals R1 to R3 of the unidirectional multiplex communication. The space-division multiplex communication method can effectively use a frequency by a multiplex communication system of space-dividing a radio beam.

Abstract: A private branch radio communication system includes a portable radio transmitter and a portable radio receiver. The system further includes first and second repeaters respectively located in first and second areas within a given premises and coupled to each other through an optical fiber cable. A radio signal output from the portable radio transmitter is converted into an optical signal by the first repeater, and is then supplied to the second repeater through the optical fiber cable, and converted into a radio signal which is received by the portable radio receiver.