Cellular radio communication system with frequency reuse

• US 7,227,850 B2
• Filed: 04/04/2001
• Issued: 06/05/2007
• Est. Priority Date: 04/04/2001
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Dahlman, Erik, Parkvall, Stefan
• Primary Examiner(s): NGUYEN, HANH N
• Application Number:
  US09/825,353
• Publication Number:
  US 20020145988A1
• Time in Patent Office: 2,253 Days
• Field of Search: 370/335, 370/342, 370/329, 370/331, 370/330, 370/315, 370/316, 370/208, 370/426, 370/432, 370/441, 370/320, 370/341, 455/447, 455/450, 455/452.1, 455/62, 455/63, 455/436, 455/422.1, 455/442, 455/448, 455/446, 455/453
• US Class Current: 370/330
• CPC Class Codes: H04B 7/2618 using hybrid code-time division multiple access [CDMA-TDMA]
• CPC Class Codes: H04L 5/0021 in which codes are applied as a frequency-domain sequences, e.g. MC-CDMA
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04W 16/12 Fixed resource partitioning
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection

Abstract

Different frequency reuse values are associated with different channels, e.g., different types of channels in a cellular communications system. For a high speed downlink shared type of channel, the frequency reuse may be greater than one in order to achieve higher data rates. On the other hand, the frequency reuse may be set to one for other channel types, e.g., dedicated channels including both uplink and downlink dedicated channels. Alternatively, the frequency reuse may also be set greater than one for channels in addition to the downlink shared channel, e.g., one or more dedicated downlink channels, while a frequency reuse of one is deployed for one or more uplink dedicated channels. Using different frequency reuse values reduces inter-cell interference, particularly at cell borders, while still maintaining existing soft handover schemes for dedicated channels if one or more of the channels is a code division multiple access (CDMA) type of channel.

Claims

1. A method for use in cellular communications system having a first type of channel and a second type of channel different from the first type of channel, comprising:

establishing a connection with a mobile radio in a first cell that includes the first type of channel being assigned a first frequency for a first uplink or downlink channel direction and the second type of channel being assigned a second different frequency for a second uplink or downlink channel direction, where the first and second uplink or downlink channel directions may be different or the same;

associating a first frequency reuse for the first type of channel such that the first type of channel in the first uplink or downlink channel direction in a second cell adjacent to the first cell is assigned a third frequency different from the first and second frequencies, and

associating a second frequency reuse for the second type of channel such that the second type of channel in the second uplink or downlink channel direction in the second cell adjacent to the first cell is assigned the second frequency,

wherein one of the channels is a code division multiple access (CDMA) channel.

2. The method in claim 1, wherein the first type of channel is a shared channel and the second type of channel is a dedicated channel.

3. The method in claim 2, wherein the shared channel is a downlink channel and the second type of channel includes a downlink dedicated channel associated with the downlink shared channel.

4. The method in claim 2, wherein the second channel type also includes an uplink dedicated channel, associated with the downlink shared channel.

5. The method in claim 2, wherein the first channel type is a high speed downlink shared channel.

6. The method in claim 2 wherein the first channel type is a high speed uplink shared channel.

7. The method in claim 1, wherein the first type of channel is a downlink channel and the second type of channel is an uplink channel.

8. The method in claim 7, wherein the first type of channel includes multiple downlink channels and the second type of channel includes one uplink channel associated with the multiple downlink channels.

9. The method in claim 1, wherein the first type of channel is a channel not configured to use soft handover, and the second type of channel is a channel that is configured to use soft handover.

10. The method in claim 1, wherein the other of the first and second channels is an orthogonal frequency division multiplexing (OFDM) channel.

11. A control node for use in a cellular radio communications system in which a connection may be established with a mobile radio in a first cell that includes a first type of channel associated with a first frequency for a first uplink or downlink channel direction and a second different type of channel associated with a second different frequency for a second uplink or downlink channel direction, where the first and second uplink or downlink channel directions may be different or the same, comprising:

a memory configured to store frequency reuse values for different types of channels including the first and second channel types, and

a controller configured to associate a first frequency reuse with the first type of channel in the first cell and a second frequency reuse with the second type of channel in the first cell,

wherein the controller is further configured to assign a third frequency different from the first and second frequencies to the first type of channel in the first uplink or downlink channel direction in a second cell adjacent to the first cell and to assign the second frequency to the second type of channel in the second uplink or downlink channel direction in the second cell adjacent to the first cell, and

wherein one of the first and second types of channels is a code division multiple access (CDMA) channel.

12. The control node in claim 11, wherein the control node is a radio network controller coupled to one or more base stations.

13. The control node in claim 11, wherein the first channel is not a channel configured to use soft handover, and the second channel is a channel that is configured to use soft handover.

14. The control node in claim 11, wherein the first channel type is a shared channel and the second channel type is a dedicated channel.

15. The control node in claim 14, wherein the first channel type is a high speed downlink shared channel.

16. The control node in claim 11, wherein the first channel type is a high speed uplink shared channel.

17. The control node in claim 16, wherein the second type of channel includes a downlink dedicated channel.

18. The control node in claim 11, wherein the first type of channel includes a downlink channel and the second type of channel includes an uplink channel.

19. The control node in claim 18, wherein the first type of channel includes multiple downlink channels and the second type of channel includes one uplink channel.

20. The control node in claim 11, wherein the first frequency reuse is greater than the second frequency reuse.

21. The control node in claim 11, wherein the other of the first and second channels is an orthogonal frequency division multiplexing (OFDM) channel.

22. A communications node for use in code division multiple access (CDMA) cellular communications system where a connection established with a mobile radio in a first cell includes a first type of channel assigned to a first frequency for a first uplink or downlink channel direction and a second different type of channel assigned to a second different frequency for a second uplink or downlink channel direction, where the first and second uplink or downlink channel directions may be different or the same, comprising:

means for associating a first frequency reuse for the first CDMA channel type used in the first cell;

means for assigning a third frequency different from the first and second frequencies to the first type of channel in the first uplink or downlink channel direction in a second cell adjacent to the first cell,

means for associating a second frequency reuse for the second CDMA channel type used in the cell; and

means for assigning the second frequency in the second uplink or downlink channel direction to the second type of channel in the second cell.

23. The communications node in claim 22, wherein the first type of CDMA channel is a shared channel and the second type of CDMA channel is a dedicated channel.

24. The communications node in claim 23, wherein the shared channel is a downlink channel and the second type of channel includes a downlink dedicated channel.

25. The method in claim 24, wherein the second type of CDMA channel also includes an uplink dedicated channel.

26. The communications node in claim 22, wherein the first type of CDMA channel is a high speed downlink shared channel and the second type of CDMA channel is a high speed uplink shared channel.

27. The communications node in claim 26, wherein the first type of CDMA channel includes multiple downlink channels and the second type of CDMA channel includes an uplink channel.

28. A mobile radio node for use in a cellular radio communications system in which a connection may be established with the mobile radio node in a first cell that includes a first type of channel assigned to a first frequency in a first uplink or downlink channel direction and a second type of channel assigned to a second different frequency for a second uplink or downlink channel direction, where the first and second uplink or downlink channel directions may be different or the same, comprising:

circuitry configured to support a communication in the first cell using first type of channel assigned to the first frequency in the first uplink or downlink channel direction and the second type of channel assigned to the second different frequency for the second uplink or downlink channel direction,

wherein the circuitry is further configured to support a communication in a second different cell using the first type of channel assigned to a third different frequency in the first uplink or downlink channel direction and the second type of channel assigned to the second different frequency for the second uplink or downlink channel direction.

29. The mobile radio node in claim 28, comprising:

handover circuitry configured to perform a first type of handover of the communication carried on the first type of channel and to perform a second type of handover of the communication carried on the second type of channel,

wherein at least one of the first and second types of channels is a code division multiple access (CDMA) channel.

30. The mobile radio node in claim 28, wherein the first type of channel has a first frequency reuse and the second type of channel a second different frequency reuse.