초록

A method of using radio frequency communications is taught for location of an automobile for the convenience of the owner. In addition, a method of using magnetic dead reckoning is taught. Methods and apparatus using cellular phones are taught.

대표청구항 ▼

A method of using radio frequency communications is taught for location of an automobile for the convenience of the owner. In addition, a method of using magnetic dead reckoning is taught. Methods and apparatus using cellular phones are taught. ving corresponding element of said reception weight vec

A method of using radio frequency communications is taught for location of an automobile for the convenience of the owner. In addition, a method of using magnetic dead reckoning is taught. Methods and apparatus using cellular phones are taught. ving corresponding element of said reception weight vector respectively at the other input, and an adder adding signals from said plurality of multipliers; and said transmission directivity control circuit includes a transmission weight vector calculating unit providing a transmission weight vector based on a result of estimation from said transmission propagation path estimating circuit, and a plurality of second multipliers each receiving at one input a transmission signal, and receiving said transmission weight vector at the other input and applying to said plurality of antennas respectively. 7. A radio equipment changing antenna directivity on real time basis and transmitting/receiving signals to/from a plurality of terminals by time division of said signal into a plurality of slots, comprising: a plurality of antennas arranged in a discrete manner; and a transmission circuit and a reception circuit sharing said plurality of antennas for transmitting/receiving signals; wherein said reception circuit includes a reception signal separating circuit for separating a signal from a specific terminal among said plurality of terminals, based on signals from said plurality of antennas, when a reception signal is received, and a reception propagation path estimating circuit estimating a propagation path from said specific terminal based on signals from said plurality of antennas, when said reception signal is received; said transmission circuit includes a transmission propagation path estimating circuit predicting a propagation path when a transmission signal is transmitted, based on a result of estimation by said reception propagation path estimating circuit, and a transmission directivity control circuit updating said antenna directivity when said transmission signal is transmitted, based on the result of estimation by said transmission propagation path estimating circuit; wherein each said slot includes a training data area provided within said slot and having a prescribed number of training data, and a data area provided successive to said training data area and having a plurality of data each representing information to be transmitted/received; said reception propagation path estimating circuit provides a first estimation value and a second estimation value of the propagation path from said specific terminal, based on data of said training data area and said data area, respectively; and said transmission propagation path estimating circuit predicts propagation path when said transmission signal is transmitted, by extrapolation of said first and second estimation values. 8. The radio equipment according to claim 7, wherein said training data area is provided at a head of said slot. 9. The radio equipment according to claim 7, wherein said reception propagation path estimating circuit successively provides a first reception coefficient vector and a second reception coefficient vector corresponding to impulse response of said specific terminal of the propagation path from said specific terminal, based on a plurality of data in said training data area and said data area. 10. The radio equipment according to claim 9, wherein said first reception coefficient vector and said reception coefficient vector are successively derived by steepest descent method. 11. The radio equipment according to claim 9, wherein said first reception coefficient vector and said second reception coefficient vector are successively derived by recursive least square method. 12. A radio equipment changing antenna directivity on real time basis and transmitting/receiving signals to/from a plurality of terminals by time division of said signal into a plurality of slots, comprising: a plurality of antennas arranged in a discrete manner; and a transmission circuit and a reception circuit sharing said plurality of antennas for transmitting/receiving signals; wherein said reception circuit includes a reception signa