Fixed frequency interference avoidance enhancement

• US 6,760,319 B1
• Filed: 07/05/2000
• Issued: 07/06/2004
• Est. Priority Date: 07/05/2000
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Gerten, Leo Joseph, Harmke, Chuck Bromley, Harnist, Kevin Alan, Mahoney, Mark Robert
• Primary Examiner(s): Vanderpuye, Kenneth
• Assistant Examiner(s): KADING, JOSHUA A
• Application Number:
  US09/610,022
• Time in Patent Office: 1,462 Days
• Field of Search: 370/320, 370/329, 370/332, 370/335, 370/441, 375/132
• US Class Current: 370/335
• CPC Class Codes: H04B 1/715 Interference-related aspects
• CPC Class Codes: H04B 2001/7154 with means for preventing interference

Abstract

A system and method is provided for removing channels in a frequency hopping scheme having strong interference or interferers in a wireless communication system. The present invention employs signal strength measurements on N number channels of the frequency hopping scheme to determine M number of channels to be avoided. The system and/or method then modifies the frequency hopping scheme to avoid transmission over the M channels. The M channels to avoid can be communicated to wireless units involved in the communication system, so that the members of the wireless communication system can frequency hop together over the modified frequency hopping scheme.

Claims

1. A system for avoiding channels having relatively strong interference in a wireless communication environment formed entirely of mobile units employing a frequency hopping scheme comprising:

a power measurement component at each mobile unit adapted to scan N total channels employed in the frequency hopping scheme and measure signal strength of the N channels;

a central control system component at each mobile unit operatively coupled to the power measurement component, the central control system component adapted to receive signal measurement information and modify the frequency hopping scheme to avoid transmitting through M channels of the N total channels;

a first register bank coupled to the central control system component, the first register bank storing synthesizer codes for generating frequency hopping over the N total channels and a second register bank coupled to the central control system, the second register bank storing synthesizer codes for generating frequency hopping over N-M channels; and

a first hop selection kernel component for addressing the first register bank and a second hop selection kernel component for addressing the second register bank, the first hop selection kernel component having a modulo of N for addressing the first register bank and the second hop selection kernel component having a modulo of N-M for addressing the second register bank.

2. A method for avoiding channels having strong interference in a wireless communication system employing a frequency hopping scheme comprising the steps of:

determining M channels with strong interference out of N total channels in the frequency hopping scheme by scanning the N total channels to determine the signal strength of each of the N total channels and identifying M channels above a predetermined signal strength to be avoided, the step of identifying M channels above a predetermined signal strength comprising the steps of identifying channels above a first threshold and placing those channels on a first list and identifying channels above a second threshold and below the first threshold and placing those channels on a second list; and

modifying the frequency hopping scheme to avoid transmitting through the M channels in the frequency hopping scheme.

3. The method of claim 2, wherein the channels on the first list are identified as channels to first avoid and then the channels on the second list are identified as channels to secondly avoid until a total of M channels are identified.

4. A method for avoiding channels having strong interference in a wireless communication system employing a frequency hopping scheme comprising the steps of:

determining M channels with strong interference out of N total channels in the frequency hopping scheme;

modifying the frequency hopping scheme to avoid transmitting through the M channels in the frequency hopping scheme; and

wherein the step of modifying the frequency hopping scheme to avoid transmitting through the M channels in the frequency hopping scheme comprising the steps of defining an alternate register bank of N-M channels, removing synthesizer codes for the M channels to be avoided, loading the alternate register bank with N-M synthesizer codes and reconfiguring the address scheme to address the alternate register bank.

5. A method for avoiding channels having strong interference in a wireless communication system employing a frequency hopping scheme comprising the steps of:

determining M channels with strong interference out of N total channels in the frequency hopping scheme;

modifying the frequency hopping scheme to avoid transmitting through the M channels in the frequency hopping scheme;

wherein the step of modifying the frequency hopping scheme to avoid transmitting through the M channels in the frequency hopping scheme comprising the step of replacing the M channels with guardband channels.

6. A method for avoiding channels having strong interference in a wireless communication system employing a frequency hopping scheme comprising the steps of:

determining M channels with strong interference out of N total channels in the frequency hopping scheme;

modifying the frequency hopping scheme to avoid transmitting through the M channels in the frequency hopping scheme; and

replacing the M channels with guardband channels, determining if any additional channels of the N channels besides the M channels have signal strengths above a predetermined signal strength up to M additional channels, providing an alternate bank register having N-M channels, removing synthesizer codes for the M additional channels to be avoided, loading the N-M register bank with N-M synthesizer codes and reconfiguring the address scheme to address the alternate register bank.

7. A method for avoiding channels having strong interference in a wireless communication system employing a frequency hopping scheme comprising the steps of:

determining M channels with strong interference out of N total channels in the frequency hopping scheme;

modifying the frequency hopping scheme to avoid transmitting through the M channels in the frequency hopping scheme;

wherein the wireless communication system comprises a master device and at least one slave wherein the master performs the step of determining M channels with strong interference out of N total channels in a frequency hopping scheme, and communicates the M channels to be avoided over a communication link between the master and the at least one slave and both the master and the at least one slave perform the step of modifying the frequency hopping scheme to avoid transmitting through the M channels; and

the master further performing the step of determining if the at least one slave supports interference avoidance before the step of communicating the M channels to be avoided over a communication link between the master and the at least one slave.