Method and apparatus for reducing interference among communication systems

• US 5,649,303 A
• Filed: 04/10/1996
• Issued: 07/15/1997
• Est. Priority Date: 09/02/1994
• Status: Expired due to Term

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Brailean, Karen A., Hess, Garry C.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Nguyen, Lee
• Application Number:
  US08/629,455
• Time in Patent Office: 461 Days
• Field of Search: 455/33.1, 455/33.2, 455/33.4, 455/50.1, 455/53.1, 455/54.1, 455/54.2, 455/63, 455/67.3, 455/34.1, 370/337, 370/347, 370/348, 379/59, 379/60
• US Class Current: 455/63.3
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/244 Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]
• CPC Class Codes: H04W 52/38 TPC being performed in particular situations

Abstract

A first communication system (110) is provided with information on communication channels of a second communication system (130), such that these channels can be monitored to determine the likelihood of interference between the systems (110, 130). Based on the monitoring of these channels, a predetermined action is taken with respect to transmission of signal within the first communication system (110) to reduce the likelihood of interference between the systems (110, 130).

Claims

1. In a communication device, a method comprising the steps of:

operating on a first communication system using a time division multiplexed wireless channel;

monitoring a control channel on a second communication system operationally independent of the first communication system, which control channel indicates communications within the second communication system on an adjacent communication channel to the time division multiplexed wireless channel;

determining that there is a potential for interference with users of the second communication system by characterizing transmissions on the control channel; and

based at least upon the monitoring of the control channel and upon a determination that there is a potential for interference with users of the second communication system, automatically taking a predetermined action with respect to subsequent transmissions of signals within the first communication system, in order to reduce interference with respect to users of the second communication system operating on the adjacent communication channel.

2. The method of claim 1, wherein the step of automatically taking a predetermined action includes the step of selecting from amongst a set of predetermined actions that include reducing power of subsequent transmissions, controlling peak frequency deviation of subsequent transmissions, controlling audio modulation bandwidth of subsequent transmissions, and transferring subsequent transmissions to a different wireless channel.

3. The method of claim 1, wherein the step of automatically taking a predetermined action comprises the step of reducing transmit power for subsequent operations on the time division multiplexed channel.

4. A method for reducing a likelihood of interference between first and second independent communication systems, comprising the steps of:

providing a communication unit which transmits signals on a particular channel of the first independent communication system;

providing the communication unit with a list of communication channels for monitoring, the list of communication channels including a control channel used by the second independent communication system to manage transmissions on a channel adjacent to the particular channel;

monitoring, by the communication unit, the control channel for activity indicating communication on the channel adjacent to the particular channel; and

automatically taking, by the communication unit, a predetermined action with respect to subsequent transmissions of signals within the first independent communication system in order to reduce the likelihood of interference between the first and second independent communication systems, based upon the monitoring of the control channel used by the second independent communication system.

5. The method of claim 4, wherein the step of automatically taking a predetermined action comprises the step of executing, by the communication unit, a hand-off algorithm.

6. The method of claim 4, wherein the step of automatically taking a predetermined action comprises the step of adjusting, by the communication unit, a transmit power level.

7. A method for reducing a likelihood of interference between first and second independent communication systems, comprising the steps of:

providing a communication unit which transmits signals on a particular channel of the first independent communication system;

providing the communication unit with a list of communication channels for monitoring, the list of communication channels including a control channel used by the second independent communication system to manage transmissions on a channel adjacent to the particular channel;

monitoring, by the communication unit, the control channel for activity indicating communication on the channel adjacent to the particular channel; and

automatically reducing power with respect to subsequent transmissions of signals within the first independent communication system in order to reduce the likelihood of interference between the first and second independent communication systems, based upon the monitoring of the control channel used by the second independent communication system.

8. A method, comprising the steps of:

providing a communication unit which transmits signals on a first frequency used by a first communication system;

providing the communication unit with a list of communication channels for monitoring, the list of communication channels including a control channel used by a second communication system operating independently from the first communication system;

monitoring, by the communication unit, the control channel for communication activity which indicate potential communication on a second frequency with which the communication unit would interfere if transmitting on the first frequency; and

automatically taking action with respect to subsequent transmissions of signals on the first frequency in order to reduce the likelihood of interference between the first and second independent communication systems, in response to communication activity on the control channel.