Abstract: Even in areas where signals from only two or less base stations are available for position calculation, the mobile handset position can be calculated, expanding the position information service area and improving the usefulness. When the number of base stations available for position calculation is three or more, the position calculation is performed based on trilateration. When the number of available base stations is two or one, the position calculation is performed by using a two-station-based position calculation method or a one-station-based position calculation method according to the number of available base stations.

Abstract: A radio handset includes: a signal receiver for receiving signals from a plurality of radio stations; a reception timing analyzer for analyzing reception timings of signals received by the signal reception means; a radio station selector for selecting radio stations to be used in a position calculation; and a position calculator for calculating a position of a signal reception point by using the reception timings of the signals from the selected radio stations. The radio station selector selects the radio stations to be used in the position calculation in such a manner that when reception timings of signals from two or more of the radio stations cannot be separated from one another, it is decided to exclude a signal from at least one of these radio stations.

Abstract: Under a multi-path environment, receive timing for the incoming wave of the minimum propagation delay time cannot be accurately measured using the prior art.

Abstract: A position calculation method that calculates the correct position of a terminal even when errors are not distributed symmetrically for positive and negative values, by calculating the position of a terminal using the delay time of received signals. The method calculates a first range that is a difference between a range from the terminal to each of antenna and a range from the terminal to a base antenna, the range being calculated from a wireless signal delay time; calculates a second range that is a difference between a range from an assumed terminal position for calculation to each antenna and a range from the assumed terminal position for calculation to the base antenna; calculates a likelihood of the position of the terminal, repeats these procedures to obtain a point where the likelihood is maximized, and determines an obtained most likely solution as the position of the terminal.

Abstract: Under a multi-path environment, the receive timing for an incoming wave of the minimum propagation delay time cannot be accurately measured in the prior art. By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation section 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timings that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, the reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time.

Abstract: A positioning method, which is related to a technique to measure a correct position of a terminal by preventing time required for the position measurement, of calculating a position of a receiver according to signals from a plurality of wireless transmitters includes a first step of measuring propagation delay time of the signal from each of the wireless transmitters and calculating a position of the receiver and a standard deviation about measuring distance error, a second step of calculating a positioning error of the receiver a third step of determining, according to the positioning error calculated by the second step, wireless transmitters in directions nearer to a direction in which the positioning error is large, and a fourth step of re-detecting signals from the wireless transmitters determined by the third step and thereby re-calculating the position of the receiver.

Abstract: To extend the areas where a mobile handset can determine its position using radio waves, the present invention provides a mobile handset that is equipped with both position calculation means using radio waves from GPS satellites and position calculation means using RF carriers from cellular base stations. Positioning results obtained from both of these position calculation means are combined and weighted with GPS positioning reliability and cellular positioning reliability, respectively. A weighted mean of these results is then output as a final position calculation result.

Abstract: A location calculation method for calculating, by using propagation delay time of signals received from wireless transmitters, a location of a reception point of the signals to thereby reduce errors in the distance measurement due to an erroneous detection of a path of a received signal includes first step of measuring reception timing of signals received from the wireless transmitters, second step of estimating, according to results of measurement of the reception timing obtained by the first step, an erroneous result of measurement, and third step of removing the results of measurement estimated as the erroneous results by the second step from the results of measurement of the reception timing obtained by the first step, and thereby calculating the location of the reception point.

Abstract: An offset measuring method according to the present invention accurately measures a transmitting time offset of a base station. The offset measuring method for receiving signals from the radio base station and measuring the transmitting time offset of the radio base station includes the steps of calculating estimated values of transmitting time offset based on signals received at a plurality of observation points and selecting a minimum from the estimated offsets to determine the selected minimum value as transmitting time offset of the radio base station.

Abstract: There is provided a heat sink comprising a base plate provided with a plurality grooves and concave portions, each of which has a substantially trapezoidal cross section having a flat bottom face and inclined side faces and is formed into a tapered shape, formed between the adjacent grooves by plastic deformation; and a plurality of thin-sheet fins which are inserted in the grooves and are crimped from both sides by the inclined side faces formed by the plastic deformation of the concave portion.

Abstract: An apparatus, system and method for measuring timing of a signal transmitted from a wireless base station antenna, are disclosed. The apparatus includes an accurate time reception antenna, a cellular antenna that receives the reception time of the signal transmitted from the wireless base station antenna, and a reference clock generator that compares the reception time value and the accurate time value. The system includes an accurate time generator of an accurate time value, a wireless base station antenna that transmits a first signal, and a transmission timing measurement apparatus having a first antenna and a second antenna that receives the accurate time value and the first signal, and that outputs an offset of the first signal from the accurate time value, and may additionally include a center for the storage offsets.

Abstract: At least three base stations transmit a specific signal pattern at given intervals. This allows a mobile station that received this signal pattern to locate itself by using the positional information about the base stations, sending timing (or information on phase shift from the reference time) of each signal pattern from the base stations, and signal pattern receiving time information. At least one of the above base stations changes the sending timing of the signal pattern. On this occasion, the mobile terminal or station is notified of the altered reference time offset (or information on phase shift from the reference time) of the sending timing or updated sending timing of the signal pattern.

Abstract: A wireless position measurement terminal, a wireless position measurement system, and a method for performing delay profile calculation window sizing in a wireless position measurement system, are disclosed. The terminal includes a delay profile calculating circuit, and a window setter connected to the delay profile calculating circuit that varies a range for a delay profile calculating window according to at least one information item within a remote received signal. The terminal may additionally include a memory circuit that stores positional information, wherein the window setter changes the range according to a correlation of the positional information and the information item. The system includes the terminal, and at least three base stations, wherein at least one of the base stations provides the remote received signal to the terminal.

Abstract: In a cellular radio communication system including a plurality of base stations and a plurality of terminals in which one cell is divided into a plurality of sectors, each of the base stations transmits and receives control information by an omnidirectional beam and transmits and receives traffic information by a directional beam. Alternatively, each of the base stations transmits and receives control information by a directional beam with a time difference of the same control information in a plurality of sectors within one cell and transmits and receives traffic information by a directional beam.

Abstract: A coaxial resonant slot antenna having a novel structure is provided to further reduce the dimensions of radio terminals incorporating such an antenna. Also provided are a novel method of fabricating such a coaxial resonant slot antenna and a radio terminal having a novel structure using such a coaxial resonant slot antenna. An entire strip conductor is arranged inside a flat conductive cubic such that the strip conductor is insulated from the conductive cubic. A connection point between the strip conductor and a radio frequency transmission line is provided at a position about 1/4 of wavelength away from one end of the strip conductor. A slot is shaped into a narrow rectangle, a generally upside-down "U", or a generally upside-down "U" having another slot on each end. It is desired that the center slot crosses the strip conductor along the length thereof and in the height direction thereof, the distance between the ends being equivalent to about 1/2 of wavelength used.

Abstract: An antenna of small size is provided which can be mass-produced, which is suitable for use with a portable receiver and which does not require provision of a separate matching circuit. The antenna includes a plurality of meander antennas printed on at least one dielectric film and satisfying respectively different resonance conditions in a frequency band used by the receiver, at least one dielectric solid cylinder for winding the dielectric film therearound, and a dielectric hollow cylinder for covering the dielectric film wound around the dielectric solid cylinder. The individual meander antennas printed on the dielectric film do not make direct electrical contact with each other, and one of the meander antennas connected to a feeder or a helical antenna surrounding the dielectric solid cylinder acts to produce multiple resonance by means of electromagnetic coupling with the other meander antennas, thereby widening the frequency band.