Pioneer Electronic Corporation

Hitachi, Ltd.

Kenichiro Kawasaki

Shozaburo Sakaguchi

Takaharu Noguchi

Masafumi Nakamura

Isao Endo

Harushige Nakagaki

Tsutomu Honda

Shinichi Takemura

Shouzaburo Sakaguchi

A signal acquisition method for a GPS receiver which eliminates the necessity of a clock circuit for keeping the current time and also a backup battery for memory is disclosed. According to the signal acquisition method, upon starting of acquisition of a GPS satellite after the power source to the GPS receiver is turned on, using a matched filter, an acquisition operation is performed for objects of all of GPS satellites which may possibly be disposed until after a signal of at least one of the GPS satellites is acquired.

Signal acquisition and reception method for a global positioning system

A method for searching a carrier frequency and code phase of a signal received by a GPS receiver. The method includes steps of: quantizing the received signal; sampling the quantized signal at a first speed by a carrier frequency generated in the receiver; storing the samples in memory at a first speed; reading the samples from memory at a second speed; and determining the correlation between a code of the carrier frequency generated in the receiver and the received signal. The second speed is faster than the first speed.

Signal processing method for a GPS receiver

A signal processing circuit for a GPS receiver wherein the search time for a code phase is decreased to decrease the time required for catching of radio waves of an artificial satellite without increasing the circuit scale very much. The signal processing circuit comprises, in addition to a carrier correlator and a code correlator, a change-over circuit for changing over the connection to the code correlator so that the code correlator operates as a carrier correlator before wave forms of an object artificial satellite are caught but operates as a code correlator after waveforms of the object artificial satellite are caught.

Signal processing circuit for GPS receiver

A magnetic recording/reproducing apparatus for recording a signal onto a magnetic tape and reproducing a recorded signal comprises magnetic heads mounted on a rotary cylinder, a tape driving mechanism, high speed running control device for driving a reel shaft to rotate at a speed higher than a normal recording/reproducing speed, tape-running detecting device, reel motor starting device for generating a ramp voltage having a suitable gradient, a switch for turning on/off the tape running speed control by the high speed running control device and adding device. In the apparatus the cylinder rotation speed follow-up control never comes out in making the high speed running of the tape rise, so that the relative speed between the head and tape is maintained to substantial constant.

Magnetic recording/reproducing apparatus which maintains a constant

A vehicle navigation apparatus comprises a self-contained positioning system, GPS positioning system, and a controller for performing arithmetic operation on the basis of the output of any one of the self-contained positioning system and the GPS positioning system so as to display various navigation information on a display. The controller corrects the bearing data based on the self-contained positioning system with respect to that based on the GPS positioning system if the bearing data of self-contained positioning system differs from that of the GPS positioning system by more than a predetermined value when a vehicle velocity determined on the basis of the position data from any one of the positioning systems exceeds a predetermined value.

Vehicle navigation apparatus

A satellite transmission capturing method for the GPS receiver whereby PLL operation is stopped until the demodulation intensity of a demodulator reaches a predetermined level. The frequency of the reproduced carrier of the demodulator is consecutively changed in increments of a frequency range wider than the PLL capture range in search for satellite transmissions. This allows the demodulation intensity to reach the predetermined level in fewer frequency changing steps than ever before. Thus the time required to capture the desired satellite transmission is reduced. Where the integral time constant of a low pass filter in the demodulator is set to a value smaller than that in effect during PLL operation until the demodulation intensity of the demodulator reaches the predetermined level, a wide band demodulation intensity curve is used in search for satellite transmissions until that level is exceeded. This further widens the frequency range in which to search satellite transmissions, and the time required to capture the desired satellite transmission is further shortened accordingly.

Satellite transmission capturing method for GPS receiver

A GPS receiver comprising a plurality of demodulators. A satellite transmission search range is divided into as many frequency ranges as the demodulators so that one demodulator is assigned to one divided frequency range. Each demodulator searches a target satellite transmission within the frequency range assigned thereto. The GPS receiver of this construction significantly reduces the time required initially to capture the desired satellite transmission.

Growing community of inventors

Saitama, Japan

Kenichiro Kawasaki