Matsushita Electric Industrial Co., Ltd.

Akio Teranishi

Ryobun Tachita

Ken Ikeda

Nobuo Genji

Kohji Itoh

Transmitter and receiver system comprises a transmitter comprising means for generating a pseudo noise code, a first mixer for modulating transmission data by the pseudo noise code, phase shifting means for shifting the phase of a reference frequency signal by 90.degree., a second mixer for frequency converting an output of the first mixer by one of the reference signal and the phase-shifted reference signal, a third mixer for frequency-converting the pseudo noise code by the other one of the two reference signals, and adding means for adding outputs of said second and third mixers. The system also comprises a receiver comprising means for shifting the phase of the transmitted signal by 90.degree., arithmetic operating means for multiplying the transmitted signal with the phase shifted signal means, and filter for allowing only the signal regarding the transmission data in an output of the arithmetic operating means to pass.

Transmitting and receiving systems

A GPS receiver comprising a pseudonoise generator for simultaneously generating pseudonoise signals respectively corresponding to satellite electromagnetic waves transmitted from two or more satellites, an oscillator for simultaneously regenerating carrier waves of the plurality of satellite electromagnetic waves, and a plurality of demodulators responsive to the regenerated carrier waves and the pseudonoise signals to demodulate individual satellite electromagnetic waves independently, to thereby regenerate data transmitted from individual satellites, each demodulator being operative, during demodulation, to detect a set of phases of one pseudonoise signal and one regenerated carrier wave relative to one satellite electromagnetic wave on time division basis and including a first mixer for mixing of one pseudonoise signal, a second mixer for mixing of one regenerated carrier wave and a filter, whereby a set of phases of one pseudonoise signal and one regenerated carrier wave is changed to another set at timed relationship with transmission of data from individual satellites to measure a phase of one pseudonoise signal relative to one satellite electromagnetic wave, thereby tracking data transmitted from individual satellites on the basis of the measured phase.

GPS receiver

A diversity receiver provides plural antennas, one receiving part for receiving the radio wave from one of the plural antennas and a control part for selecting one antenna from the plural antennas, wherein the antenna is selected in a manner that an antenna receiving the most intensive radio wave is detected by switching of the plural antennas in-turn in a time period T.sub.1, and the detected antenna is selected for receiving an information of the radio wave in a time period T.sub.2, the plural antennas may be disposed with distances shorter than a wavelength of the radio wave.

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Ebina, Japan

Akio Teranishi