Method and device for transmission power selection and bit rate selection for channels with open loop power control

• US 20020128031A1
• Filed: 01/02/2001
• Published: 09/12/2002
• Est. Priority Date: 01/02/2001
• Status: Active Grant

• Current Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Valkealahti, Kimmo
• Granted Patent: US 6,778,839 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/267 taking into account the information rate

Abstract

A method and device for selecting transmission power and bit rate in a wireless telecommunications network, especially in the context of open loop power control, is disclosed. Transmission power and bit rate are selected in response to input parameters so as to minimize a cost function representing induced interference and transport delay.

Claims

1. A method for providing a transmission signal having appropriate transmission power and bit rate, in a wireless telecommunications system, comprising the steps of:

providing a command signal (39) having a magnitude indicative of calculated transmission bit rate and calculated transmission power, in response to an input parameter signal (47), said calculated transmission bit rate and said calculated transmission power having magnitudes selected to minimize a cost function representing induced interference and transport delay, and

providing the transmission signal (22) having the calculated transmission bit rate and the calculated transmission power, in response to the command signal (39).

2. The method of claim 1, wherein said steps are carried out in an open loop power control system (28).

3. The method of claim 2, wherein the cost function is a linear function of the induced interference and the transport delay.

4. The method of claim 2 further comprising the step of providing a broadcast parameter signal (24), wherein the transmission signal (22) is from a mobile device (20) to a base station (26), the broadcast parameter signal (24) has a magnitude indicative of at least one of the input parameters, and the input parameter signal (47) is provided in response to the broadcast parameter signal (24).

5. The method of claim 2, wherein the input parameter signal (47) has a magnitude indicative of input parameters that include pathloss (L) and total interference (I) as a product (L.I).

6. The method of claim 5, wherein the input parameters also include maximum delay (D), maximum power (P), ebno value (E), chip rate (C), and packet size (S).

7. The method of claim 6, wherein the bit rate (b) is given by

8. The method of claim 7, wherein the transmission power (p) is given by

9. The method of claim 5, wherein the transmission signal (22) is sent from a base station (36) to a mobile device (30), and wherein the product of pathloss and interference is approximately calculated prior to sending the transmission signal (22) in order to determine bit rate and transmission power of the transmission signal (22).

10. The method of claim 9, wherein transmission bit rate and transmission power is calculated at a radio network controller (31).

11. The method of claim 9, wherein the product of pathloss and interference is approximated using a measurement report signal (35) from the mobile device (30), the measurement report signal (35) having a magnitude indicative of measured signal-to-interference ratio.

12. The method of claim 9, wherein the product of pathloss and interference is approximated by statistically examining other active users in a sector.

13. The method of claim 9, wherein the product of pathloss and interference is estimated based on an assumption that the mobile device (30) is located in a sector where interference from outside the sector is a fixed proportion of interference from inside the sector.

14. The method of claim 6, wherein the ebno value is increased when a frame error is detected, and decreased when a frame is received correctly.

15. The method of claim 2, wherein the wireless telecommunications system employs wideband code division multiple access.

17. The device of claim 16, wherein open loop power control is employed.

18. The device of claim 17, wherein the cost function is a linear function of the induced interference and the transport delay.

19. The device of claim 17 further comprising a parameter storage module (55) responsive to a broadcast parameter signal (51), for providing the input parameter signal (47), wherein the transmitter module (44), the parameter storage module (55) and the computing module (43) are located at a mobile device (50), and wherein the broadcast parameter signal (51) has a magnitude indicative of at least one of the input parameters.

20. The device of claim 17, wherein the input parameter signal (47) has a magnitude indicative of input parameters that include pathloss (L) and total interference (I) as a product (L.I).

21. The device of claim 20, wherein the input parameters also include maximum delay (D), maximum power (P), ebno value (E), chip rate (C), and packet size (S).

22. The method of claim 21, wherein the bit rate (b) is given by

23. The method of claim 22, wherein the transmission power (p) is given by

24. The device of claim 20, wherein the transmitter module (44) is located at a base station (66), and wherein the computing module (43) is equipped and programmed to approximately calculate the product of pathloss and interference in order to determine bit rate and transmission power of the transmission signal (22).

25. The device of claim 24, wherein the computing module (43) is located at a radio network controller (71).

26. The device of claim 24, wherein the product of pathloss and interference is approximated using a measurement report signal (65) from the mobile device, the measurement report signal (65) having a magnitude indicative of measured signal-to-interference ratio.

27. The device of claim 24, wherein the product of pathloss and interference is approximated by statistically examining other active users in a sector.

28. The device of claim 24, wherein the product of pathloss and interference is estimated based on an assumption that the mobile device is located in a sector where interference from outside the sector is a fixed proportion of interference from inside the sector.

29. The device of claim 21, wherein the ebno value is increased when a frame error is detected, and decreased when a frame is received correctly.

30. The device of claim 17, wherein the wireless telecommunications system employs wideband code division multiple access.

16. A device for transmitting a signal having appropriate transmission power and bit rate, in a wireless telecommunication system, comprising:

a transmitter module (44), responsive to an command signal (39) having a magnitude indicative of calculated transmission bit rate and calculated transmission power, for providing a transmission signal (22) having the calculated transmission bit rate and the calculated transmission power; and

a computing module (43), responsive to an input parameter signal (47), for providing the command signal (39), said transmission bit rate and said transmission power having magnitudes selected to minimize a cost function representing induced interference and transport delay.