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: A signal transmission and reception method, and a base station and a mobile terminal therefor are disclosed. In a communication system including a base station and at least a mobile terminal, the transmission of the data signal from the base station to each mobile terminal is controlled in accordance with the manner in which the pilot signal transmitted from the base station to each mobile terminal is received by the mobile terminal. In the signal transmission method, the proper one of a plurality of signal multiplexing schemes is selected based on the control signal received from each mobile terminal, and the transmission signal is multiplexed by the selected signal multiplexing scheme and transmitted to each mobile terminal. The transmission signal includes the data signal and the dedicated pilot signal transmitted to the mobile terminal.

Abstract: It is desired to carry out CDMA communication using an optimum spread code for minimizing inter-channel interference according to communication conditions. For this purpose, under condition that a communication area covered by a base station is variable, notification of spread code reassignment is issued while communication is being made between the base station and a mobile terminal. Thereafter, a currently assigned spread code is changed so as to reduce interference between a channel used for communication in progress and another channel. In spread code reassignment, an adjustment is made to provide the same long code for channels which would otherwise incur significant interference.

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: In a method for locating a position of a terminal with use of weak signals, a combined weight to be used to separate a path from others through correlation calculation is obtained from a plurality of delay profiles measured in course of time. The obtained weight is used to combine the delay profiles and a path detection is carried out on the combined delay profiles.

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: Phase and amplitude deviations, which are generated, for example, by cables connecting an array antenna of a CDMA base station and the base station, are calibrated in the baseband.

Abstract: An apparatus, system and method for measuring timing of a signal transmitted from a wireless base station antenna. The apparatus and system include 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 an accurate time value and the first signal, and that outputs an offset of the first signal from the accurate time value. The method includes receiving an accurate time, receiving the reception time transmitted from the wireless base station antenna, receiving the reception time value and the accurate time value, and comparing of the reception time value and the accurate time value.

Abstract: In a wireless terminal position measuring method for estimating the position of a terminal using signals sent from at least three base stations accommodated by a cellular communication system, position of the terminal is estimates according to the triangulation method by selecting three base stations arbitrarily, a plurality of estimated positions thus calculated are stored in a memory and averaged thereafter to obtain a final estimated position.

Abstract: A radio communication system and method having an array antenna and a weighting arrangement that provides a downlink array weight for a downlink on the basis of information about bearings of a plurality of incoming signals received through a plurality of uplinks, and transmission power control information about transmission data to be transmitted through a downlink.

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, receive timing for the incoming wave of the minimum propagation delay time cannot be accurately measured using 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 timing 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, 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: Phase and amplitude deviations, which are generated, for example, by cables connecting an array antenna of a CDMA base station and the base station, are calibrated in the baseband.

Abstract: A periodical signal is transmitted from a cellular base station. A memory circuit having a capacity of the signal for one cycle is provided. Newly received information is added to information previously accumulated in the memory circuit, and the resultant information is again accumulated in the memory circuit, thereby enabling the received information to be stored in the memory circuit having the capacity for only one cycle of the signal. Conventionally, a large amount of memory has been required to perform coherent adding for a long time period, whereas the present invention can reduce the circuit scale and the amount of memory, and also reduce the number of times of operations required for the long-period coherent adding, when a mobile station is located using a cellular communication system.

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: The disclosed invention provides a wireless communications terminal apparatus that calculates its accurate position, eliminating the influence of a repeater on the calculation without using complicated processing. The terminal apparatus receives signals transmitted from a plurality of radio stations and calculates its position, using the received signals. The terminal apparatus comprises repeater detection means for detecting a signal from a repeater which transmits signals that are generated on the basis of signals transmitted from one of the radio stations and indistinguishable from the signals transmitted from that radio station from among the received signals and position calculation means for calculating its position. When the repeater detection means has detected a signal from a repeater, the position calculation means ignores the detected signal from the repeater and calculates the terminal position, using the received signals from other radio stations.

Abstract: In a system having an uplink and a downlink differing from each other in communication capacity, an array weight for the downlink is estimated. An interference subspace for the downlink is constituted on the basis of bearing information collected from the uplink and transmission control information received from mobile stations. An optimum downlink array weight is estimated on the basis of an array response vector obtained from a signal subspace, and an interference subspace. The appropriate array weight enables the reduction of transmission power by which signals are transmitted by a base station and interference with other cells can be reduced. Consequently, line capacity is increased.

Abstract: A radio terminal that receives signals from a plurality of radio stations to calculate its current position has: interference canceling means for canceling each interference signal from the plurality of received signals; a plurality of delay profile generating means for generating delay profiles of the plurality of interference-canceled received signals with use of respective corresponding codes; and position calculating means for calculating its current position, which is a signal receiving point, with use of the plurality of delay profiles, whereby advantageously reducing the capacity of a memory mounted in the mobile terminal while the position calculation is speeded up

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: 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.