Radio device

• US 6,590,532 B1
• Filed: 12/18/2001
• Issued: 07/08/2003
• Est. Priority Date: 06/23/1999
• Status: Expired due to Fees

• Current Assignee: Japan As Represented By President of National Cancer Center, Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Japan As Represented By President of National Cancer Center, Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Doi, Yoshiharu, Ohgane, Takeo, Ogawa, Yasutaka
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): MULL, FRED H
• Application Number:
  US09/926,769
• Time in Patent Office: 567 Days
• Field of Search: 342/378, 342/372, 455/276--27, 455/303-305
• US Class Current: 342/378
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04B 7/0848 Joint weighting
• CPC Class Codes: H04B 7/0851 using training sequences or error signal minimizing error signal H04B7/0854

Abstract

A radio equipment 1000 separates a signal of a specific terminal from signals from adaptive array antennas #1 to #4, based on a reception weight vector calculated by a reception weight vector calculator 20. Reception coefficient vector calculator 22 provides an impulse response of a signal propagation path of the specific terminal. A transmission coefficient vector estimator 32 predicts a propagation path at the time of transmission, from the result of estimation by the reception coefficient vector calculator 22. The transmission weight vector calculator 30 controls, based on the result of prediction by the transmission coefficient vector estimator 32, the antenna directivity at the time of transmission. Thus, degradation of error rate of the down link generated by the time difference between up/down links can be suppressed.

Claims

1. 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 first data area of a first prescribed size provided in said slot so as to distinguish transmission/reception to/from said specific terminal, and

a second data area of a second prescribed size provided in an area succeeding and apart by a prescribed interval from said first data area, in said slot to distinguish transmission/reception to/from said specific terminal;

said reception propagation path estimating circuit provides the first estimation value and a second estimation value of said specific terminal based on data in said first and second data areas, respectively; and

said transmission propagation path estimating circuit predicts propagation path when said transmission signal is transmitted, by extrapolating said first and second estimation values.

2. The radio equipment according to claim 1, wherein

said first data area includes a first training data area, and said second data area includes a second training data area.

3. The radio equipment according to claim 2, wherein

said first training data area is provided at a head of said slot, and said second training data area is provided at a tail of said slot.

4. The radio equipment according to claim 3, wherein

said reception propagation path estimating circuit provides a first reception coefficient vector and a second reception coefficient vector corresponding to an impulse response of said specific terminal of the propagation path from said specific terminal, based on the data of said first and second training data areas, respectively.

5. The radio equipment according to claim 4, wherein

said reception propagation path estimating circuit provides said first reception coefficient vector and said second reception coefficient vector, by ensemble average of each of the signals received by said plurality of antennas and a signal from said specific terminal separated by said reception signal separating circuit.

6. The radio equipment according to claim 1, wherein

the reception signal separating circuit includes

a reception weight vector calculating unit receiving reception signals from said plurality of antennas and providing, on real time basis, a reception weight vector for separating a signal from said specific terminal,

a plurality of first multipliers each receiving at one input reception signals from said plurality of antennas respectively, and receiving 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 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 the 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 plurality of estimation values of the propagation path from said specific terminal, based on the data of said training data area and said data area, respectively; and

said transmission propagation path estimating circuit regresses said plurality of estimation values and predicts propagation path when said transmission signal is transmitted, by extrapolation based on a result of regression.

13. The radio equipment according to claim 12, wherein

said training data area is provided at a head of said slot.

14. The radio equipment according to claim 12, wherein

said reception transmission path estimating circuit successively provides a plurality of reception coefficient vectors corresponding to impulse response from 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.

15. The radio equipment according to claim 14, wherein

said plurality of reception coefficient vectors are successively provided by steepest descent method.

16. The radio equipment according to claim 14, wherein

said plurality of reception coefficient vectors are successively provided by recursive least square method.

17. A radio equipment changing antenna directivity on real time basis and transmitting/receiving signals time divisionally to/from a plurality of terminals, 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 said reception signal separating circuit includes

a reception weight vector calculating unit receiving reception signals from said plurality of antennas and providing, on real time basis, a reception weight vector for separating a signal from said specific terminal,

a plurality of first multipliers each receiving at one input the reception signals from said plurality of antennas respectively and receiving corresponding element of said reception weight vector at the other input, and

an adder adding signals from said plurality of multipliers;

said transmission directivity control circuit includes

a moving speed determining unit determining speed of movement of said specific terminal based on a result of estimation by said reception propagation path estimating circuit,

a transmission weight vector calculating unit providing a transmission weight vector based on a result of estimation by said transmission propagation path estimating circuit,

a switching circuit receiving said transmission weight vector and said reception weight vector, and selectively outputting in accordance with a result of determination by said moving speed determining unit, and

a plurality of second multipliers receiving at one input a transmission signal and receiving an output of said switching circuit at the other input respectively, and applying to said plurality of antennas, respectively.

18. A radio equipment changing antenna directivity on real time basis and transmitting/receiving signals time divisionally to/from a plurality of terminals, 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

the reception signal separating circuit includes

a reception weight vector calculating unit receiving reception signals from said plurality of antennas and providing, on real time basis, a reception weight vector for separating a signal from said specific terminal,

a reception signal level operating unit receiving the reception signals from said plurality of antennas and providing a reception level of the signal from said specific terminal,

a plurality of first multipliers receiving at an input the reception signals from said plurality of antennas respectively, and receiving corresponding elements of said reception weight vector at the other input respectively, and

an adder adding the signals from said plurality of multiplying units; and

said transmission directivity control circuit includes

a reception signal level determining unit determining a reception signal level of said specific terminal based on a result of operation of said reception signal level operating unit,

a transmission weight vector calculating unit providing a transmission weight vector based on a result of estimation by said transmission propagation path estimating circuit,

a switching circuit receiving said transmission weight vector and said reception weight vector and selectively outputting in accordance with a result of determination by said reception signal level determining unit, and

a plurality of multipliers receiving at one input the transmission signal and receiving an output of said switching circuit at the other input respectively, and providing to said plurality of antennas, respectively.