Method and apparatus for communication unit frequency assignment

• US 5,551,064 A
• Filed: 07/27/1994
• Issued: 08/27/1996
• Est. Priority Date: 07/27/1994
• Status: Expired due to Term

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Royer, Ronald L., Nobbe, Dan W.
• Primary Examiner(s): Eisenzopi, Reinhard J.
• Assistant Examiner(s): Nguyen, Lee
• Application Number:
  US08/281,310
• Time in Patent Office: 762 Days
• Field of Search: 455/62, 455/63, 455/34.1, 455/34.2, 455/54.1, 455/56.1, 455/54.2, 455/53.1, 455/33.1, 379/59
• US Class Current: 455/62
• CPC Class Codes: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04W 16/06 Hybrid resource partitioning, e.g. channel borrowing
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

A method and apparatus for establishing frequency assignments for a fixed radio communication unit of plural fixed radio communication units coupled via a controller. A controller functions to have the communication unit measure transmitted signal strengths, and to request the other fixed radio communication units to transmit at assigned frequencies. The system functions to identify and select one (or more) of the frequencies measured having the lowest signal strength and adjacent channel and/or co-channel interference characteristics beneath set threshold level(s). The system also operates to repeat the process for each fixed radio communication unit, until all are assigned frequencies.

Claims

1. A method of determining frequency assignment for a first of a plurality of fixed radio communication units each coupled to a communication controller, comprising:

(a) requesting all of the plurality of fixed radio communication units except the first fixed radio communication unit to transmit each at a predetermined frequency, and requesting the first fixed radio communication unit to measure a signal characteristic of each of a first group of frequencies including at least each predetermined frequency;

(b) determining a first frequency of the first group of frequencies having a lowest measured signal characteristic;

(c) determining whether an adjacent one of the first group of frequencies has a measured signal characteristic of at least a first predetermined threshold, and if not, selecting the first frequency for use by the first fixed radio communication unit;

(d) when the determining step of step (c) has a positive determination, determining a next frequency of the first group frequencies having a next lowest measured signal strength and repeating step (c) for the next frequency;

(e) repeating step (d) until one of the first group of frequencies is selected or step (d) is repeated a predetermined number of repetitions; and

(f) changing at least one of the first and second predetermined thresholds if step (d) is repeated the predetermined number of repetitions.

2. The method of claim 1 wherein step (c) further comprises (i) determining whether two or more frequencies of the first group of frequencies, together yielding intermodulation interference at the first frequency, have a measured signal characteristic of one of a group consisting of the first and a second predetermined threshold, and (ii) if both determining steps of step (c) have a negative determination, selecting the first frequency.

3. The method of claim 1 further comprising:

(g) performing steps (a) through (e) for all of the fixed radio communication units.

4. The method of claim 3 further comprising repeating a cycle of steps (a) through (g) until a predetermined number of the plurality of fixed radio communication units select a same frequency as selected in a previous cycle.

5. A method of determining frequency assignment for a first of a plurality of fixed radio communication units each having a tunable transceiver and coupled to a communication controller, comprising:

(a) controlling all of the plurality of fixed radio communication units except the first fixed radio communication unit to transmit each at a predetermined frequency, and controlling the first fixed radio communication unit to measure a signal strength of a first group of frequencies including at least each predetermined frequency;

(b) determining a first frequency of the first group of frequencies having a lowest measured signal strength;

(c) determining whether two or more frequencies of the first group of frequencies, together yielding intermodulation interference at the first frequency, have a measured signal strength of at least a first predetermined threshold, and if not selecting the first frequency for use by the first fixed radio communication unit;

(d) when the determining step of step (c) has a positive determination, determining a next frequency of the first group of frequencies having a next lowest measured signal strength and repeating step (c) for the next frequency;

(e) repeating step (d) until one of the first group of frequencies is selected or a predetermined number of repetitions of step (d) is completed; and

(f) changing at least one of the first and second predetermined threshold if step (d) is repeated the predetermined number of repetitions.

6. The method of claim 5 wherein step (c) further comprises (i) determining whether an adjacent one of the first group of frequencies has a measured signal strength of at least one of a group consisting of the first predetermined threshold and a second predetermined threshold, and (ii) if both determining steps of step (c) have a negative determination, selecting the first frequency.

7. The method of claim 5 further comprising:

(g) performing steps (a) through (e) for all of the plurality of fixed radio communication units.

8. A communications unit coupled, to a communications controller unit which is coupled to plural other communications unit, operable for selecting a frequency assignment for a communication channel, comprising:

a transceiver;

control means, coupled to the transceiver and the communications controller unit, for requesting all of the plural other communication units to transmit each at least one predetermined frequency, and for controlling the transceiver to measure a signal characteristic for each of a first group of frequencies including at least each predetermined frequency and send each measured signal characteristic to the control means;

store means, coupled to the control means, for receiving and storing each measured signal characteristic;

comparison means, coupled to the store means, for determining a first frequency of the first group of frequencies having an optimal measured signal characteristic; and

determining means, coupled to the store means and control means, for determining whether an adjacent one of the first group of frequencies has a measured signal characteristic of at least a first predetermined threshold;

wherein the control means is further operable for selecting the first frequency for use by the first communication unit when the determining means has a negative determination and, in response to a positive determination by the determining means, is operable for controlling the comparison means to determine a next frequency of the first group of frequencies having a next lowest measured signal strength, and the determining means to determine whether a further adjacent one of the first group of frequencies to the next frequency has a measured signal strength of at least the first predetermined threshold and, is operable for changing the first predetermined threshold.

9. The communication unit of claim 8 wherein the determining means is further operable for determining whether two or more frequencies of the first group of frequencies, together yielding intermodulation interference at the first frequency, have a measured signal characteristic of at least a second predetermined threshold, and the control means is further operable for selecting the first frequency for use by the communication unit in response to negative determinations by the determining means.

10. The communication unit of claim 8 wherein the communication unit is a radio port and the communications controller unit is a radio port control unit.