Method of improving quality of radio connection

• US 6,433,737 B2
• Filed: 05/18/2001
• Issued: 08/13/2002
• Est. Priority Date: 11/05/1997
• Status: Expired due to Fees

• Current Assignee: Nokia Telecommunications Oy (Nokia Corporation)
• Original Assignee: Nokia Telecommunications Oy (Nokia Corporation)
• Inventors: Katz, Marcos
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US09/859,415
• Publication Number:
  US 20010024173A1
• Time in Patent Office: 452 Days
• Field of Search: 342/367, 455/507, 455/517, 455/562, 455/69
• US Class Current: 342/367
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04W 16/28 using beam steering

Abstract

The invention relates to a method of improving the quality of a radio connection (170) in a cellular radio network. Relevant for the invention, the cellular radio network includes a base station system (126) and a subscriber terminal (150). A bidirectional radio connection (170) using a directional antenna beam (304) is provided between the base station system (126) and the subscriber terminal (150). In the method, in the base station system (126) an angle of incidence (302) of the directional antenna beam (304) is formed on the basis of a received radio signal (170A) transmitted by the subscriber terminal (150). The base station system (126) transmits a radio signal (170B) to the subscriber terminal (150) in the direction of an angle of departure (308) formed on the basis of the angle of incidence (302). In accordance with the invention, a ratio is formed for the imbalance between the downlink and uplink traffics. The processing of the directional antenna beam (304) of the radio signal (170A, 170B) is controlled on the basis of the formed ratio.

Claims

1. A method of improving the quality of a radio connection in a cellular radio network including a base station system, a subscriber terminal, and a bi-directional radio connection between the base station system and the subscriber terminal using a directional antenna beam, the method comprising:

receiving, by the base system, uplink traffic of the bi-directional radio connection transmitted by the subscriber terminal;

transmitting, by the base station system, downlink traffic of the bi-directional radio connection to the subscriber terminal;

forming a ratio for imbalance between the downlink traffic and the uplink traffic; and

controlling processing of the directional antenna beam on a basis of the ratio.

2. The method of claim 1, wherein the transmitting downlink traffic comprises controlling a forming of the directional antenna beam on the basis of the ratio.

3. The method of claim 1, further comprising controlling processing of the directional antenna beam of the bi-directional radio connection received by the base station system from the subscriber terminal on the basis of the ratio.

4. The method of claim 1, wherein the ratio is formed by subtracting a number of signal received on the uplink traffic during a period of time from a number of signals transmitted on the downlink during that given period of time;

and

dividing a difference thus obtained by a sum of the number of signals transmitted on the downlink traffic and the number of signals received on the uplink traffic, the sum being formed using the number of signals received on the uplink traffic and the number of signals transmitted on the downlink traffic that were used for forming the difference.

5. The method of claim 4, wherein when the ratio obtains a value of about zero, the traffics are deemed balanced.

6. The method of claim 4, wherein when the ratio obtains a value greater than zero, the traffics are deemed unbalanced in such a manner that the downlink traffic is heavier than the uplink traffic.

7. The method of claim 4, wherein when the ratio obtains a value lower than zero, the traffics are deemed unbalanced in such a manner that the uplink traffic is heavier than the downlink traffic.

8. The method of claim 4, wherein when the ratio obtains a value 1, only the downlink traffic has traffic.

9. The method of claim 4, wherein when the ratio obtains a value −

1, only the uplink traffic has traffic.

10. The method of claim 1, further comprising selecting a suitable algorithm for forming the directional antenna beam on the basis of the ratio.

11. The method of claim 1, wherein a width of the directional antenna beam is determined on the basis of the ratio.

12. The method of claim 11, wherein the width of the directional antenna beam depends on an equation in which a proportionality constant is divided by a difference, which difference is formed by subtracting the ratio from a sensitivity parameter which is greater than one.

13. The method of claim 11, wherein the width of the directional antenna beam of the bi-directional radio connection used by the base station system directly depends on an uncertainty time elapsed between a formulation of a last angle of incidence and a use of the bi-directional radio connection.

14. The method of claim 13, wherein the width of the directional antenna beam of the bi-directional radio connection transmitted by the base station system to the subscriber terminal directly depends on the uncertainty time elapsed between the formation of the last angle of incidence and a transmission moment.

15. The method of claim 13, wherein the width of the directional antenna beam of the bi-directional radio connection received by the base station system from the subscriber terminal directly depends on the uncertainty time elapsed between the formation of the last angle of incidence and a reception moment.

16. The method of claim 13, wherein the width of the directional antenna beam is increased in a direction of movement of the subscriber terminal.

17. The method of claim 13, wherein the width of the directional antenna beam of the bi-directional radio connection used by the base station system directly depends on the channel of the radio connection established on a basis of a preceding radio signal received or transmitted by the subscriber terminal.

18. The method of claim 13, wherein the width of the directional antenna beam of the bi-directional radio connection used by the base station system directly depends on a time elapsed between a channel estimation of the radio connection performed on a basis of a preceding radio signal or transmitted by the subscriber terminal, and a use of the bi-directional radio connection.

19. The method of claim 13, wherein the dependence on the uncertainty time is linear or in accordance with any other increasing function.

20. The method of claim 13, wherein the width of the directional antenna beam is changed in predetermined steps.

21. The method of claim 13, wherein the width of the directional antenna beam is changed steplessly.

22. The method of claim 13, wherein the width of the directional antenna beam is inversely affected by a distance between the base station system and the subscriber terminal.

23. The method of claim 13, wherein the method is used in bi-directional radio connections comprising at least one of sporadic and asymmetric traffic.

24. The method of claim 23, wherein the method is used in connection with packet transmission.

25. A cellular radio network comprising:

a base station system;

a subscriber terminal; and

a bi-directional radio connection between the base station system and the subscriber terminal using a directional antenna beam,

wherein the base station system is configured to receive uplink traffic of the bi-directional radio connection transmitted by the subscriber terminal, and the base station system is configured to transmit downlink traffic of the bi-directional radio connection to the subscriber terminal, and wherein the base station system is configured to form a ratio for an imbalance between the downlink traffic and the uplink traffic, and

the base station is configured to control processing of the directional antenna beam of the transmitted or received bi-directional radio connection on a basis of the ratio.

26. The cellular radio network of claim 25, wherein the base station system is configured to form, on the basis of the ratio, the directional antenna beam of the bi-directional radio connection to be transmitted to the subscriber terminal.

27. The cellular radio network of claim 25, wherein the base station system is configured to form, on the basis of the ratio, the directional antenna beam of the bi-directional radio connection received from the subscriber terminal.

28. The cellular radio network of claim 25, wherein the base station system is configured to form the ratio by

subtracting a number of signals received on the uplink traffic during a given period of time from a number of signals transmitted on the downlink traffic during that given period of time; and

dividing the difference thus obtained by a sum of the number of signals transmitted on the downlink traffic and the number of signals received on the uplink traffic, the sum being formed using the number of signals received on the uplink traffic and the number of signals transmitted on the downlink traffic that were used for forming the difference.

29. The cellular radio network of claim 28, wherein when the ratio obtains a value of about zero, the traffics are deemed balanced.

30. The cellular radio network of claim 28, wherein when the ratio obtains a value greater than zero, the traffics are deemed unbalanced in such a manner that the downlink traffic is heavier than the uplink traffic.

31. The cellular radio network of claim 28, wherein when the ratio obtains a value lower than zero, the traffics are deemed unbalanced in such a manner that the uplink traffic is heavier than the downlink traffic.

32. The cellular radio network of claim 28, wherein when the ratio obtains a value of 1, only the downlink traffic has traffic.

33. The cellular radio network of claim 28, wherein the ratio obtains a value of −

1, only the uplink traffic has traffic.

34. The cellular radio network of claim 25, wherein the base station system is configured to select a suitable algorithm for forming the directional antenna beam on the basis of the ratio.

35. The cellular radio network of claim 25, wherein the base station system is configured to determine a width of the directional antenna beam on the basis of the ratio.

36. The cellular radio network of claim 35, wherein the base station system is configured in such a manner that the width of the directional antenna beam depends on an equation in which a proportionality constant is divided by a difference, which difference is formed by subtracting the ratio from a sensitivity parameter which is greater than one.

37. The cellular radio network of claim 35, wherein the base station system is configured to form the width of the directional beam of the bi-directional radio connection to be directly dependent on an uncertainty time elapsed between a formation of a last angle of incidence and a use of the bi-directional radio connection.

38. The cellular radio network of claim 37, wherein the base station system is configured to form a width of the directional antenna beam of the bi-directional radio connection to be transmitted to the subscriber terminal to be directly dependent on the uncertainty time elapsed between the formation of the last angle of incidence and a transmission moment.

39. The cellular radio network of claim 37, wherein the base station system configured to form the width of the directional antenna beam of the bi-directional radio connection received from the subscriber terminal to be directly dependent on the uncertainty time elapsed between the formation of the last angle of incidence and a reception moment.

40. The cellular radio network of claim 37, wherein the base station system is configured to increase the width of the directional antenna beam in a direction of movement of the subscriber terminal.

41. The cellular radio network of claim 37, wherein the base station system is configured to form the width of the directional antenna beam of the bi-directional radio connection used by the base station system to be directly dependent on a channel of the radio connection established on a basis of a preceding radio signal received or transmitted by the subscriber terminal.

42. The cellular radio network of claim 37, wherein the base station system is configured to form the width of the directional antenna beam of the bi-directional radio connection used by the base station system to be directly dependent on a time elapsed between a channel estimation of the radio connection performed on a basis of a preceding radio signal received or transmitted by the subscriber terminal, and a use of the bi-directional radio connection.

43. The cellular radio network of claim 37, wherein the dependence on the uncertainty time is linear or in accordance with any other increasing function.

44. The cellular radio network of claim 37, wherein the width of the directional antenna beam is changed in predetermined steps.

45. The cellular radio network of claim 37, wherein the width of the directional antenna beam is changed steplessly.

46. The cellular radio network of claim 37, wherein the width of the directional antenna beam is inversely affected by a distance between the base station system and the subscriber terminal.

47. The cellular radio network of claim 37, wherein the cellular radio network is used in bi-directional radio connections comprising at least one of sporadic and asymmetric traffic.

48. The cellular radio network of claim 47, wherein the cellular radio network is used in connection with packet transmission.