Method and arrangement relating to radio communications systems

• US 6,385,457 B1
• Filed: 07/02/1998
• Issued: 05/07/2002
• Est. Priority Date: 07/04/1997
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Dam, Henrik, Karlsson, Jonas
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): BEAMER, TEMICA M
• Application Number:
  US09/109,060
• Time in Patent Office: 1,405 Days
• Field of Search: 455/561, 455/562, 455/277.1, 455/277.2, 455/456, 455/457, 455/450, 455/436, 455/12.1, 455/13.1, 342/371, 342/373, 342/374
• US Class Current: 455/456.2
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A radio communications system includes a radio base station provided with an array antenna. The antenna lobes of the array antenna can be directed onto a terminal with the aid of a generated directional estimate. The directional estimate is based on a signal received from the terminal. A method registers a generated directional estimate together with a terminal recognition character. The directional estimate is read when the radio connection with the terminal changes channel. The antenna lobe is directed on the basis of the direction estimate, immediately communication commences over the new channel. A radio base station is equipped with a database in which the terminal recognition character and the direction estimate are registered.

Claims

1. A method pertaining to a radio communications system which includes at least one base station controller and at least one radio base station which establishes radio communication with at least one terminal and which only passes signaling information between the at least one terminal and the base station controller, and the at least one radio base station having antenna lobes that can be directed towards the one terminal, and said base station controller switching system communication by the at least one terminal from a first to a second radio channel, said method performed by the radio base station comprising the steps of:

a) receiving, over said first radio channel, signals that have a given direction-of-arrival from the one terminal;

b) estimating the direction-of-arrival of the received signals such as to obtain a directional estimate;

c) identifying a terminal recognition character;

d) registering the terminal recognition character and said directional estimate in a storage device;

e) identifying said second radio channel, which is allocated by said base station controller, for communication with the one terminal;

f) reading-out said directional estimate from the storage device;

g) directing the antenna lobe for the second radio channel in accordance with said directional estimate which is read out; and

h) communicating with the one terminal over said second radio channel.

2. A method according to claim 1, wherein identification of the terminal recognition character in accordance with step c) is implemented by decoding an access message sent by the one terminal.

3. A method according to claim 2, wherein the one recognition character is a random number.

4. A method according to claim 1, wherein identification of the terminal recognition character in accordance with step c) is implemented by decoding a channel allocation message in downlink.

5. A method according to claim 4, wherein the terminal recognition character includes an identity of a new allotted channel.

6. A method according to claim 1, wherein the terminal recognition character according to step c) includes an identity of the first radio channel.

7. A method according to claim 1, wherein identification of said second radio channel in accordance with step e) is implemented by receiving a channel activation command that contains channel identity.

8. A method according to claim 1, wherein reading of the directional estimate in accordance with step f) is implemented by reference to said terminal recognition character.

9. A method according to claim 1, wherein the first and the second radio channels are logical channels.

10. A method according to claim 1, wherein the first and the second radio channels are physical channels.

11. A method according to claim 1, further comprising the step of applying the method to a GSM system.

12. A method pertaining to a radio communications system which includes at least one base station controller and at least one radio base station that can establish radio communication with at least one terminal and that only passes signaling information between the one terminal and the base station controller, and the radio base station having antenna lobes that can be directed towards the terminal, and the base station controller switching system communication by the one terminal from a first to a second radio channel, said method performed by the radio base station comprising the steps of:

a) receiving, over said first radio channel, signals that have a given direction-of-arrival from the terminal;

b) estimating the direction-of-arrival such as to obtain a directional estimate;

c) identifying a mobile station recognition character;

d) registering the recognition character and said directional estimate;

e) identifying said second radio channel, which is allocated by the base station controller, for communication with the terminal;

f) reading-out said directional estimate;

g) directing one of the antenna lobes for the second radio channel in accordance with said directional estimate; and

h) communicating with the channel over said second radio channel wherein identification of said second radio channel in accordance with step e) is implemented in conjunction with receiving from the terminal a new access signal that contains the mobile station recognition character.

13. A radio base station having a first connection to a communications network which has at least one of a plurality of terminals placed at its disposal upon request, said radio base station only passing information between the communications network and the plurality of terminals, said radio base station comprising:

at least one array antenna;

at least one transceiver unit which connects with the array antenna and which includes

a) an uplink branch having means for selecting at least one desired radio channel of the array antenna, means for detecting data received in the selected radio channel, means for forwarding the detected data from the selected radio channel over the first connection, and means for generating a directional estimate from data received in the selected radio channel, and

b) a downlink branch having means that receives a bit stream from the first connection, and means for modulating and amplifying said bit stream and for transmitting said bit stream in a radio channel allocated by the communications network via said array antenna;

means in connection with the uplink branch for identifying a mobile station recognition character in the detected data of the uplink branch;

means in connection with the downlink branch for identifying a mobile station recognition character from the bit stream of the downlink branch;

means for linking an obtained directional estimate with said recognition character; and

a database connected to the transceiver unit;

wherein said directional estimate and said recognition character being registered in the data base and read-out therefrom and wherein the uplink branch and downlink branch direct the antenna lobe based upon the direction estimate read-out from the database.

14. A radio base station according to claim 13, wherein the first connection also connects with the database for registering directional estimate and recognition character and for reading-out said directional estimate and said recognition character.

15. A radio base station according to claim 13, wherein the transceiver unit includes a database processor having connections to the uplink branch, the downlink branch and the database, wherein the database processor identifies the mobile station recognition character and obtains said directional estimate from the uplink branch and registers said recognition character and said directional estimate in the database, wherewith the database processor reads-out said recognition character and said directional estimate from the database and informs the uplink branch.

16. A radio base station according to claim 13, wherein the transceiver unit includes a connection between the uplink branch and the downlink branch over which the directional estimate is transmitted.

17. A radio base station according to claim 13 wherein the uplink branch and the downlink branch are each provided with means for directing the antenna lobe in uplink and downlink respectively.

18. A radio base station according to claim 13 wherein the radio base station is connected directly to a base station controller in a GSM system.

19. A radio base station having a first connection to a communications network which has at least one of a plurality of terminals placed at its disposal upon request, said radio base station only passing information between the plurality of terminals and the communications network, said radio base station comprising:

at least one array antenna;

at least one transceiver unit which connects with the array antenna and which includes

a) an uplink branch having means for selecting at least one desired radio channel of the array antenna, means for detecting data received in the selected radio channel, means for forwarding the detected data from the selected radio channel over the first connection, and means for generating a directional estimate from data received in the selected radio channel, and

b) a downlink branch having means that receives a bit stream from the first connection, and means for modulating and amplifying said bit stream and for transmitting said bit stream in a radio channel via said array antenna, wherewith the uplink branch and the downlink branch are adapted to direct the antenna lobe on the basis of a given directional estimate;

means in connection with the uplink branch for identifying a mobile station recognition character in the detected data of the uplink branch;

means in connection with the downlink branch for identifying a mobile station recognition character from the bit stream of the downlink branch;

means for linking an obtained directional estimate with said recognition character; and

a database connected to the transceiver unit;

said directional estimate and said terminal recognition character being registered in the data base and read-out therefrom, wherein the communications network designates the radio channel that shall be used for radio connection with the mobile station, and wherein no message is sent to the radio base station as to which mobile station uses a given channel.