Radio base device, mobile terminal device, reference signal control method, and reference signal control program

• US 20050254450A1
• Filed: 09/18/2003
• Published: 11/17/2005
• Est. Priority Date: 09/20/2002
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Ito, Tadayoshi, Miyata, Takeo
• Granted Patent: US 8,089,923 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04B 7/2681 Synchronisation of a mobile station with one base station
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 56/0085 detecting a given structure in the signal

Abstract

When the number of multiplexed connections of PSs to a CS is changed due to issuance of a connection request from other PS to the CS or the like, the CS selects a unique word pattern (new unique word) optimal for the new number of multiplexed connections, so as to request switching from an old unique word to a new unique word to each PS of the user who has established multiple access. When a response to the request for switching is received from the PS of each user, the CS transmits a synchronous burst signal including the new unique word to the PS, and the PS also returns the synchronous burst signal including the new unique word. Synchronization is thus established.

Claims

1. A radio cell station apparatus to which a plurality of personal stations can establish space division multiple access, said radio cell station apparatus transmitting to and receiving from each of said plurality of personal stations a signal including an already-known reference signal different for each personal station, comprising:

multiplexed connection number detection means for detecting number of multiplexed connections of the personal stations establishing space division multiple access; and

reference signal allocation means for allocating, by switching the reference signals that have been allocated to the personal stations establishing space division multiple access respectively prior to change in the number of multiplexed connections to reference signals capable of maintaining communication quality even after the number of multiplexed connections is changed, the switched reference signals to said plurality of personal stations respectively, when change in the number of multiplexed connections is detected in said multiplexed connection number detection means.

2. The radio cell station apparatus according to claim 1, further comprising storage means for storing a reference signal optimized for each number of multiplexed connections of the personal stations establishing space division multiple access, wherein

when the number of multiplexed connections of the personal stations establishing space division multiple access is changed, said reference signal allocation means selects reference signals optimal for the changed number of multiplexed connections from said storage means and allocates the selected reference signals to said plurality of personal stations respectively.

3. The radio cell station apparatus according to claim 2, wherein

said reference signal stored in said storage means is calculated for each number of multiplexed connections based on a high autocorrelation characteristic and a low cross-correlation characteristic.

4. A personal station establishing space division multiple access to a radio cell station apparatus, said personal station transmitting to and receiving from said radio cell station apparatus a signal including an already-known reference signal different for each personal station, comprising:

means for receiving a request for switching a reference signal from said radio cell station apparatus in accordance with change in the number of multiplexed connections of the personal stations establishing space division multiple access; and

means for switching the reference signal to a reference signal capable of maintaining communication quality even after the number of multiplexed connections is changed and transmitting a response to the request for switching to said radio cell station apparatus.

5. The personal station according to claim 4, further comprising storage means for storing a reference signal optimized for each number of multiplexed connections of the personal stations establishing space division multiple access, wherein

when the request for switching the reference signal is received from said radio cell station apparatus, a reference signal optimal for the changed number of multiplexed connections is selected from said storage means and a response to the request for switching including the selected reference signal is transmitted to said radio cell station apparatus.

6. The personal station according to claim 5, wherein

said reference signal stored in said storage means is calculated for each number of multiplexed connections based on a high autocorrelation characteristic and a low cross-correlation characteristic.

7. A method of controlling a reference signal performed by a radio cell station apparatus to which a plurality of personal stations can establish space division multiple access, said radio cell station apparatus transmitting to and receiving from each of said plurality of personal stations a signal including an already-known reference signal different for each personal station, comprising the steps of:

detecting number of multiplexed connections of the personal stations establishing space division multiple access; and

when change in the number of multiplexed connections is detected in said step of detecting the number of multiplexed connections, switching the reference signals that have been allocated to the personal stations establishing space division multiple access respectively prior to change in the number of multiplexed connections to reference signals capable of maintaining communication quality even after the number of multiplexed connections is changed, and allocating the reference signals to said plurality of personal stations respectively.

8. The method of controlling a reference signal according to claim 7, further comprising the step of storing a reference signal optimized for each number of multiplexed connections of the personal stations establishing space division multiple access, wherein

when the number of multiplexed connections of the personal stations establishing space division multiple access is changed, reference signals optimal for the changed number of multiplexed connections that have been stored are selected and the selected reference signals are allocated to said plurality of personal stations respectively.

9. The method of controlling a reference signal according to claim 8, wherein

the step of storing a reference signal optimized for each number of multiplexed connections of the personal stations establishing space division multiple access further includes the step of calculating a reference signal for each number of multiplexed connections based on a high autocorrelation characteristic and a low cross-correlation characteristic.

10. A method of controlling a reference signal performed by a personal station establishing space division multiple access to a radio cell station apparatus, said personal station transmitting to and receiving from said radio cell station apparatus a signal including an already-known reference signal different for each personal station, comprising the steps of:

receiving a request for switching a reference signal from said radio cell station apparatus in accordance with change in the number of multiplexed connections of the personal stations establishing space division multiple access; and

switching the reference signal to a reference signal capable of maintaining communication quality even after the number of multiplexed connections is changed and transmitting a response to the request for switching to said radio cell station apparatus.

11. The method of controlling a reference signal according to claim 10, further comprising the step of storing a reference signal optimized for each number of multiplexed connections of the personal stations establishing space division multiple access, wherein

when the request for switching the reference signal is received from said radio cell station apparatus, a reference signal optimal for the changed number of multiplexed connections that has been stored is selected and a response to the request for switching including the selected reference signal is transmitted to said radio cell station apparatus.

12. The method of controlling a reference signal according to claim 11, wherein

the step of storing a reference signal optimized for each number of multiplexed connections of the personal stations establishing space division multiple access further includes the step of calculating a reference signal for each number of multiplexed connections based on a high autocorrelation characteristic and a low cross-correlation characteristic.

13. A program for controlling a reference signal performed by a radio cell station apparatus to which a plurality of personal stations can establish space division multiple access, said radio cell station apparatus transmitting to and receiving from each of said plurality of personal stations a signal including an already-known reference signal different for each personal station, causing a computer to execute the steps of:

detecting number of multiplexed connections of the personal stations establishing space division multiple access; and

when change in the number of multiplexed connections is detected in said step of detecting the number of multiplexed connections, switching the reference signals that have been allocated to the personal stations establishing space division multiple access respectively prior to change in the number of multiplexed connections to reference signals capable of maintaining communication quality even after the number of multiplexed connections is changed, and allocating the reference signals to said plurality of personal stations respectively.

14. The program for controlling a reference signal according to claim 13, further causing the computer to execute the step of storing a reference signal optimized for each number of multiplexed connections of the personal stations establishing space division multiple access, wherein

when the number of multiplexed connections of the personal stations establishing space division multiple access is changed, reference signals optimal for the changed number of multiplexed connections that have been stored are selected and the selected reference signals are allocated to said plurality of personal stations respectively.

15. The program for controlling a reference signal according to claim 14, wherein

the step of storing a reference signal optimized for each number of multiplexed connections of the personal stations establishing space division multiple access further causes the computer to execute the step of calculating a reference signal for each number of multiplexed connections based on a high autocorrelation characteristic and a low cross-correlation characteristic.

16. A program for controlling a reference signal performed by a personal station establishing space division multiple access to a radio cell station apparatus, said personal station transmitting to and receiving from said radio cell station apparatus a signal including an already-known reference signal different for each personal station, causing a computer to execute the steps of:

receiving a request for switching a reference signal from said radio cell station apparatus in accordance with change in the number of multiplexed connections of the personal stations establishing space division multiple access; and

switching the reference signal to a reference signal capable of maintaining communication quality even after the number of multiplexed connections is changed and transmitting a response to the request for switching to said radio cell station apparatus.

17. The program for controlling a reference signal according to claim 16, further causing the computer to execute the step of storing a reference signal optimized for each number of multiplexed connections of the personal stations establishing space division multiple access, wherein

when the request for switching the reference signal is received from said radio cell station apparatus, a reference signal optimal for the changed number of multiplexed connections that has been stored is selected and a response to the request for switching including the selected reference signal is transmitted to said radio cell station apparatus.

18. The program for controlling a reference signal according to claim 17, wherein

the step of storing a reference signal optimized for each number of multiplexed connections of the personal stations establishing space division multiple access further causes the computer to execute the step of calculating a reference signal for each number of multiplexed connections based on a high autocorrelation characteristic and a low cross-correlation characteristic.