Power control in mobile communications system

• US 6,567,459 B1
• Filed: 11/08/1999
• Issued: 05/20/2003
• Est. Priority Date: 05/16/1997
• Status: Expired due to Term

• Current Assignee: HMD Global Oy
• Original Assignee: Nokia Corporation
• Inventors: Holma, Harri, Hakkinen, Hannu
• Primary Examiner(s): Nguyen, Lee
• Application Number:
  US09/436,450
• Time in Patent Office: 1,289 Days
• Field of Search: 375/132, 375/133, 375/135, 375/136, 375/138, 370/345, 370/347, 455/101, 455/69, 455/522, 455/562
• US Class Current: 375/132
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

The invention relates to a power control method in a mobile communications system in which transmission of a signal of one logical connection over the radio path employs hopping, such as frequency hopping, antenna hopping or timeslot hopping. According to the present invention, the method is characterized in that the quality of the signal received on the radio connection is determined on one hopping setting, such as frequency, antenna or timeslot, and the power control is carried out on the radio connection in question from hopping setting to hopping setting so that the transmission power of at least one hopping setting, such as frequency, differs from the transmission power of at least one other hopping setting, such as frequency, used on the same radio connection.

Claims

1. A power control method in a mobile communications system in which transmission of a signal of one logical connection over the radio path employs frequency hopping whereby the transmission frequency on the radio connection is changed at specific intervals among at least two hopping frequencies, the power control method comprising:

transmitting a signal with a certain transmission power at one of the hopping frequencies from a sending end of the radio connection;

determining at the receiving end of the radio connection, based on the quality of the received signal, power adjustment need for the next transmission at the same hopping frequency;

transmitting a power adjustment command to the sending end of the radio connection; and

adjusting at the sending end of the radio connection transmission power of the next transmission at said hopping frequency according to the received power adjustment command, wherein the transmission power is adjusted on said radio connection from hopping frequency to hopping frequency so that the transmission power of at least one hopping frequency used on the radio connection differs from the transmission power of at least one other hopping frequency used on the same radio connection.

2. The power control method according to claim 1, wherein adjusting the transmission power in a timeslot is based on the quality measured in a previous timeslot of the same frequency.

3. The power control method according to claim 1, wherein adjusting the transmission power in a timeslot is based on the quality measured in a previous timeslot.

4. The power control method according to claim 1, wherein the transmission power is only increased on the hopping frequency on which the quality of the received signal was determined, in case the quality determined for the received signal is poor.

5. The power control method according to claim 1, wherein the transmission power is increased on all the other hopping frequencies of the radio connection but the frequency on which the quality of the received signal was determined, in case the quality determined for the received signal is poor.

6. The power control method according to claim 5, wherein the transmission power is reduced on the frequency on which the quality of the received signal was determined.

7. The power control method according to claim 5, further comprising balancing the transmission power differences between the frequencies of the radio connection by increasing a low transmission power level when the difference of the transmission power levels equals the transmitter dynamics.

8. A power control method in a mobile communications system in which transmission of a signal of one logical connection over the radio path employs antenna hopping whereby the antenna used to transmit the radio signal is changed at specific intervals between at least two hopping antennas, characterized in that the method comprises the steps of

determining the quality of the signal received on the radio connection for one-antenna, and

carrying out power adjustment from hopping antenna to hopping antenna on said radio connection so that the transmission power of transmission from at least one antenna used on the radio connection differs from the transmission power of transmission from at least one other antenna used on the same radio connection.

9. A method according to claim 8, characterized by

measuring the received signal quality from timeslot to timeslot, and

adjusting the transmission power in the timeslot being dealt with based on the quality measured in the previous one timeslot of the same antenna.

10. A method according to claim 8, characterized by

measuring the received signal quality from timeslot to timeslot, and

adjusting the transmission power in the timeslot being dealt with based on the quality measured in the previous one timeslot.

11. A method according to claim 8, characterized in that the transmission power is only increased when transmitting via the hopping antenna for which the quality of the received signal was determined, in case the quality determined for the received signal is poor.

12. A method according to claim 8, characterized in that the transmission power on the radio connection is increased when transmitting via all the other hopping antennas but the antenna for which the quality of the received signal was determined, in case the quality determined for the received signal is poor.

13. A method according to claim 12, characterized in that the transmission power is reduced when transmitting via the antenna for which the quality of the received signal was determined.

14. A method according to claim 12, characterized by

determining transmission power dynamics for the transmitter, and

balancing the transmission power differences transmitted from the antennas of the radio connection by increasing a low transmission power level, in case the difference of the transmission power levels equals the transmitter dynamics.

15. A power control method in a mobile communications system in which transmission of a signal of one logical connection over a radio path employs timeslot hopping whereby the timeslot used to transmit the radio signal is changed at specific intervals between at least two hopping timeslots, the method comprising:

determining a quality of the signal received on the radio connection in one timeslot;

transmitting a power control command to a transmitting end of a radio connection; and

based on the power control command, carrying out at the transmitting end power adjustment on said radio connection from hopping timeslot to hopping timeslot so that the transmission power of at least one timeslot used on the radio connection differs from the transmission power of at least one other timeslot used on the radio connection.

16. The power control method according to claim 15, wherein adjusting the transmission power level in a timeslot is based on the quality measured in a previous timeslot.

17. The power control method according to claim 15, wherein the transmission power is only increased in the hopping timeslot in which the quality of the received signal was determined, in case the quality determined for the received signal is poor.

18. The power control method according to claim 15, wherein the transmission power is increased in all the other hopping timeslots of the radio connection but the timeslot in which the quality of the received signal was determined, in case the quality determined for the received signal is poor.

19. The power control method according to claim 18, wherein the transmission power is reduced in the timeslot in which the quality of the received signal was determined.

20. The power control method according to claim 18, further comprising balancing the transmission power differences of the timeslots of the radio connection by increasing a low transmission power level in case the difference of transmission power levels equals the transmitter dynamic.

21. A mobile communications system comprising base stations and mobile stations that communicate over a radio path with the base stations, the mobile communications system employing frequency hopping on the radio connections between the base stations and the mobile station, whereby a transmission frequency is changed at specific intervals among at least two hopping frequencies, the mobile communication system comprising means for adjusting the transmission power levels of one logical connection from hopping frequency to hopping frequency in response to a power control command received from the receiving end of a radio connection so that the transmission power levels of at least two hopping frequencies differ from each other.

22. A mobile communications system comprising base stations (BTS) and mobile stations (MS) that communicate over the radio path with the base stations (BTS), the mobile communications system employing antenna hopping on the radio connection between the base station (BTS) and the mobile station (MS), whereby the signal transfer is changed at specific intervals from antenna to antenna among at least two hopping antennas, characterized in that the mobile communications system is adapted for adjustment of the transmission power levels of one logical connection hopping antenna by hopping antenna so that the transmission power levels of transmissions from at least two hopping antennas differ from each other.

23. A mobile communications system comprising base stations and mobile stations that communicate over a radio path with the base stations, the mobile communications system employing timeslot hopping on the radio connections between the base station and the mobile station, whereby the transmission timeslot is changed at specific intervals among at least two hopping timeslots, the mobile communications system comprising means for adjusting transmission power levels of one logical connection from hopping timeslot to hopping timeslot in response to a power control command received from the receiving end of a radio connection so that the transmission power levels of at least two hopping timeslots differ from each other.