Data transmitting method and data transmitting apparatus accompanied with a plurality of transmitting of receiving antennas

• US 6,473,466 B1
• Filed: 12/07/1998
• Issued: 10/29/2002
• Est. Priority Date: 12/08/1997
• Status: Expired due to Fees

• Current Assignee: Hitachi Denshi Kabushiki Kaisha
• Original Assignee: Hitachi Denshi Kabushiki Kaisha
• Inventors: Tsukamoto, Nobuo, Akiyama, Toshiyuki, Miyashita, Atsushi, Sano, Seiichi, Nakada, Tatuhiro
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Nguyen, Dung X.
• Application Number:
  US09/206,406
• Time in Patent Office: 1,422 Days
• Field of Search: 375/261, 375/298, 375/316, 375/344, 375/295, 375/267, 375/347, 455/132-136, 455/103, 455/562, 455/277.1, 455/96, 455/98, 455/101, 342/82, 342/89, 342/74, 342/79, 370/343
• US Class Current: 375/267
• CPC Class Codes: H04B 7/0608 Antenna selection according to transmission parameters
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 2025/03694 Stop and go

Abstract

A data transmitting apparatus in which in an antenna switching of the data transmitting apparatus, a sudden change of transmission path characteristics is prevented and a state where an automatic equalizing function on the reception side can follow can be held. The apparatus has a processing circuit for gradually switching antennas of the data transmitting apparatus with respect to the time and for continuously switching one antenna from the rated level to the 0 level and for continuously switching the other antenna from the 0 level to the rated level. The apparatus operates so as to always keep the optimum constellation state in which the automatic equalizing process follows.

Claims

1. A control method of a data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising the steps of:

supplying a transmission signal to one of a plurality of transmitting antennas and transmitting said transmission signal;

selecting an appropriate one of said plurality of transmitting antennas in accordance with a state change of said transmission path during the transmission of said transmission signal; and

soft-switching the transmitting antennas from said one transmitting antenna to said selected antenna so as to continuously shift a level of said transmission signal from said one transmitting antenna to said selected transmitting antenna over a predetermined time,

wherein said data transmitting apparatus has a receiving apparatus including a reception demodulating unit with an automatic receiving-frequency-characteristics equalizing function, and said predetermined time is longer than the time that is necessary for processing said automatic equalizing function.

2. A control method of a data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising the steps of:

supplying a transmission signal to one of a plurality of transmitting antennas and transmitting said transmission signal;

selecting an appropriate one of said plurality of transmitting antennas in accordance with a state change of said transmission path during the transmission of said transmission signal; and

soft-switching the transmitting antennas from said one transmitting antenna to said selected antenna so as to continuously shift a level of said transmission signal from said one transmitting antenna to said selected transmitting antenna over a predetermined time,

wherein said information data is modulated by a quadrature amplitude modulation system.

3. A control method of a data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising the steps of:

receiving a transmission signal by one of a plurality of receiving antennas;

selecting an appropriate one of said plurality of receiving antennas in accordance with a state change of said transmission path during the reception of said transmission signal; and

soft-switching said receiving antennas from said one receiving antenna to said selected receiving antenna in a manner such that when said transmission signal is supplied from said receiving antenna to a reception demodulating unit, a signal level of said transmission signal is continuously shifted from said one receiving antenna to said selected receiving antenna over a predetermined time,

wherein said reception demodulating unit has an automatic receiving-frequency-characteristics equalizing function, and said predetermined time is longer than the time that is necessary for processing said automatic equalizing function.

4. A control method of a data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising the steps of:

receiving a transmission signal by one of a plurality of receiving antennas;

selecting an appropriate one of said plurality of receiving antennas in accordance with a state change of said transmission path during the reception of said transmission signal; and

soft-switching said receiving antennas from said one receiving antenna to said selected receiving antenna in a manner such that when said transmission signal is supplied from said receiving antenna to a reception demodulating unit, a signal level of said transmission signal is continuously shifted from said one receiving antenna to said selected receiving antenna over a predetermined time,

wherein said information data is modulated by a quadrature amplitude modulation system.

5. A control method of a data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising the steps of:

supplying a transmission signal to one of a plurality of transmitting antennas and transmitting said transmission signal;

selecting an appropriate one of said plurality of transmitting antennas in accordance with a state change of said transmission path during the transmission of said transmission signal;

soft-switching the transmitting antennas from said one transmitting antenna to said selected antenna so as to continuously shift a level of said transmission signal from said one transmitting antenna to said selected transmitting antenna over a predetermined time;

receiving said transmission signal by one of a plurality of receiving antennas;

selecting an appropriate one of said plurality of receiving antennas in accordance with a state change of said transmission path during the reception of said transmission signal; and

soft-switching said receiving antennas from said one receiving antenna to said selected receiving antenna in a manner such that when said transmission signal is supplied from said receiving antenna to a reception demodulating unit, a signal level of said transmission signal is continuously shifted from said one receiving antenna to said selected receiving antenna over a predetermined time.

6. A method according to claim 5, wherein said step of soft-switching comprises the steps of:

supplying said transmission signal from said one receiving antenna to said reception demodulating unit in a continuously decreasing manner over a predetermined time; and

supplying said transmission signal from said selected receiving antenna to said reception demodulating in a continuously increasing manner.

7. A method according to claim 5, wherein said reception demodulating unit has an automatic receiving-frequency-characteristics equalizing function, and said predetermined time is longer than the time that is necessary for processing said automatic equalizing function.

8. A method according to claim 5, wherein said information data is modulated by a quadrature amplitude modulation system.

9. A data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising:

a transmitting apparatus including a transmission modulating unit, a switching unit for switching an output of said transmission modulating unit to an appropriate one of a plurality of transmission paths in accordance with a state change of said transmission path, a switching control unit for controlling said switching unit, and a plurality of transmitting antennas which receive outputs from said switching unit and are connected to said plurality of transmission paths, respectively; and

a receiving apparatus having a receiving antenna and a reception demodulating unit with an automatic receiving-frequency equalizing function which receives an output of said receiving antenna,

wherein said switching unit includes a path soft switching unit for switching said transmission paths from the path before switching to the path after switching in a manner such that a transmitting level of a transmission signal is continuously shifted from the path before switching to the path after switching over a predetermined time and a soft control unit for generating a control signal to said soft switching unit, and

wherein said predetermined time is longer than the time that is necessary for processing said automatic receiving frequency-characteristics equalizing function.

10. A data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising:

a transmitting apparatus including a transmission modulating unit, a switching unit for switching an output of said transmission modulating unit to an appropriate one of a plurality of transmission paths in accordance with a state change of said transmission path, a switching control unit for controlling said switching unit, and a plurality of transmitting antennas which receive outputs from said switching unit and are connected to said plurality of transmission paths, respectively; and

a receiving apparatus having a receiving antenna and a reception demodulating unit with an automatic receiving-frequency equalizing function which receives an output of said living antenna,

wherein said switching unit includes a path soft switching unit for switching said transmission paths from the path before switching to the path after switching in a manner such that a transmitting level of a transmission signal is continuously shifted from the path before switching to the path after switching over a predetermined time and a soft control unit for generating a control signal to said soft switching unit, and

wherein said information data is modulated by a quadrature amplitude modulation system.

11. A data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising:

transmitting apparatus; and

a receiving apparatus including a plurality of receiving antennas, a selecting unit for selecting one of output paths from said plurality of receiving antennas in accordance with a state change of said transmission path, a selection control unit for controlling said selecting unit, and a reception demodulating unit with an automatic receiving-frequency-characteristics equalizing function which receives an output from said selecting unit,

wherein said selecting unit includes a path soft selecting unit for selecting a receiving antenna output path in a manner such that when a received reception on signal is supplied to said reception demodulating unit, a level of said reception signal is continuously shifted from the receiving antenna output path before selection to the receiving antenna path after selection over a predetermined time, and a soft control unit for getting a control signal for said soft selecting unit in response to said selection control unit, and

wherein said predetermined time is longer than the time that is necessary for processing said automatic receiving frequency-characteristics equalizing function.

12. A data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising:

a transmitting apparatus; and

a receiving apparatus including a plurality of receiving antennas, a selecting unit for selecting one of output paths from said plurality of receiving antennas in accordance with a state change of said transmission path, a selection control unit for controlling said selecting unit, and a reception demodulating unit with an automatic receiving-frequency-characteristics equalizing function which receives an output from said selecting unit,

wherein said selecting unit includes a path soft selecting unit for selecting a receiving antenna output path in a manner such that when a received reception signal is supplied to said reception demodulating unit, a level of said reception signal is continuously shifted from the receiving antenna output path before selection to the receiving antenna path after selection over a predetermined time, and a soft control unit for generating a control signal for said soft selecting unit in response to said selection control unit, and

wherein said information data is modulated by a quadrature amplitude modulation system.

13. A data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising:

a transmitting apparatus; and

a receiving apparatus including a plurality of receiving antennas, a selecting unit for selecting one of output paths from said plurality of receiving antennas in accordance with a state change of said transmission path, a selection control unit for controlling said selecting unit, and a reception demodulating unit with an automatic receiving-frequency-characteristics equalizing function which receives an output from said selecting unit,

wherein said selecting unit includes a path soft selecting unit for selecting a receiving antenna output path in a manner such that when a received reception signal is supplied to said reception demodulating unit, a level of said reception signal is continuously shifted from the receiving antenna output path before selection to the receiving antenna path after selection over a predetermined time, and a soft control unit for generating a control signal for said soft selecting unit in response to said selection control unit,

wherein said transmitting apparatus includes a transmission modulating unit, a switching unit for switching an output of said transmission modulating unit to an appropriate one of a plurality of transmission paths in accordance with a state change of said transmission path, a switching control unit for controlling said switching unit, and a plurality of transmitting antennas which receive outputs from said switching unit and are connected to said plurality of transmission paths, respectively, and

wherein said switching unit includes a path soft switching unit for switching said transmission paths from the path before switching to the path after switching in a manner such that a transmitting level of a transmission signal is continuously shifted from the path before switching to the path after switching over a predetermined time and a soft control unit for generating a control signal to said soft switching unit.

14. An apparatus according to claim 13, wherein said path soft switching unit continuously decreases and increases the output of said transmission modulating unit which passes through said path before switching and said path after switching over said predetermined time, respectively.

15. An apparatus according to claim 13, wherein said predetermined time is longer than the time that is necessary for processing said automatic receiving-frequency-characteristics equalizing function.

16. An apparatus according to claim 13, wherein said information data is modulated by a quadrature amplitude modulation system.

17. A control method of a data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising the steps of:

supplying a transmission signal to one of a plurality of transmitting antennas and transmitting said transmission signal;

selecting an appropriate one of said plurality of transmitting antennas in accordance with a state change of said transmission path during the transmission of said transmission signal; and

soft-switching the transmitting antennas from said one transmitting antenna to said selected antenna so as to continuously shift a level of said transmission signal from said one transmitting antenna to said selected transmitting antenna over a predetermined time,

wherein said information data is modulated by an 8-VSB system.

18. A control method of a data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising the steps of:

supplying a transmission signal to one of a plurality of transmitting antennas and transmitting said transmission signal;

selecting an appropriate one of said plurality of transmitting antennas in accordance with a state change of said transmission path during the transmission of said transmission signal; and

soft-switching the transmitting antennas from said one transmitting antenna to said selected antenna so as to continuously shift a level of said transmission signal from said one transmitting antenna to said selected transmitting antenna over a predetermined time,

wherein said information data is modulated by a multiple level-FM.

19. A control method of a data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising the steps of:

receiving a transmission signal by one of a plurality of receiving antennas;

selecting an appropriate one of said plurality of receiving antennas in accordance with a state change of said transmission path during the reception of said transmission signal;

soft-switching said receiving antennas from said one receiving antenna to said selected receiving antenna in a manner such that when said transmission signal is supplied from said receiving antenna to a reception demodulating unit, a signal level of said transmission signal is continuously shifted from said one receiving antenna to said selected receiving antenna over a predetermined time,

wherein said information data is modulated by an 8-VSB system.

20. A control method of a data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising the steps of:

receiving a transmission signal by one of a plurality of receiving antennas;

selecting an appropriate one of said plurality of receiving antennas in accordance with a state change of said transmission path during the reception of said transmission signal;

soft-switching said receiving antennas from said one receiving antenna to said selected receiving antenna in a manner such that when said transmission signal is supplied from said receiving antenna to a reception demodulating unit, a signal level of said transmission signal is continuously shifted from said one receiving antenna to said selected receiving antenna over a predetermined time,

wherein said information data is modulated by a multiple level-FM.

21. A data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising:

a transmitting apparatus including a transmission modulating unit, a switching unit for switching an output of said transmission modulating unit to an appropriate one of a plurality of transmission paths in accordance with a state change of said transmission path, a switching control unit for controlling said switching unit, and a plurality of transmitting antennas which receive outputs from said switching unit and are connected to said plurality of transmission paths, respectively; and

a receiving apparatus having a receiving antenna and a reception demodulating unit with an automatic receiving-frequency equalizing function which receives an output of said receiving antenna,

wherein said switching unit includes a path soft switching unit for switching said transmission paths from the path before switching to the path after switching in a manner such that a transmitting level of a transmission signal is continuously shifted from the path before switching to the path after switching over a predetermined time and a soft control unit for generating a control signal to said soft switching unit, and

wherein said information data is modulated by an 8-VSB system.

22. A data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising:

a transmitting apparatus including a transmission modulating unit, a switching unit for switching an output of said transmission modulating unit to an appropriate one of a plurality of transmission paths in accordance with a state change of said transmission path, a switching control unit for controlling said switching unit, and a plurality of transmitting antennas which receive outputs from said switching unit and are connected to said plurality of transmission paths, respectively; and

a receiving apparatus having a receiving antenna and a reception demodulating unit with an automatic receiving-frequency equalizing function which receives an output of said receiving antenna,

wherein said switching unit includes a path soft switching unit for switching said transmission paths from the path before switching to the path after switching in a manner such that a transmitting level of a transmission signal is continuously shifted from the path before switching to the path after switching over a predetermined time and a soft control unit for generating a control signal to said soft switching unit, and

wherein said information data is modulated by a multiple level-FM.

23. A data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising:

a transmitting apparatus; and

a receiving apparatus including a plurality of receiving antennas, a selecting unit for selecting one of output paths from said plurality of receiving antennas in accordance with a state change of said transmission path, a selection control unit for controlling said selecting unit, and a reception demodulating unit with an automatic receiving-frequency-characteristics equalizing function which receives an output from said selecting unit,

wherein said selecting unit includes a path soft selecting unit for selecting a receiving antenna output path in a manner such that when a received reception signal is supplied to said reception demodulating unit, a level of said reception signal is continuously shifted from the receiving antenna output path before selection to the receiving antenna path after selection over a predetermined time, and a soft control unit for generating a control signal for said soft selecting unit in response to said selection control unit, and

wherein said information data is modulated by an 8-VSB system.

24. A data transmitting apparatus for transmitting and receiving digitally modulated information data through a transmission path, comprising:

a transmitting apparatus; and

a receiving apparatus including a plurality of receiving antennas, a selecting unit for selecting one of output paths from said plurality of receiving antennas in accordance with a state change of said transmission path, a selection control unit for controlling said selecting unit, and a reception demodulating unit with an automatic receiving-frequency-characteristics equalizing function which receives an output from said selecting unit,

wherein said selecting unit includes a path soft selecting unit for selecting a receiving antenna output path in a manner such that when a received reception signal is supplied to said reception demodulating unit, a level of said reception signal is continuously shifted from the receiving antenna output path before selection to the receiving antenna path after selection over a predetermined time, and a soft control unit for generating a control signal for said soft selecting unit in response to said selection control unit, and

wherein said information data is modulated by a multiple level-FM.