Apparatus and method for protecting a communication device operating in an undesirable environment

• US 6,018,514 A
• Filed: 06/29/1998
• Issued: 01/25/2000
• Est. Priority Date: 06/29/1998
• Status: Expired due to Term

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Davidson, Allen L., Bickham, Richard S.
• Primary Examiner(s): MARCELO, MELVIN C
• Application Number:
  US09/106,401
• Time in Patent Office: 575 Days
• Field of Search: 370/217, 370/225, 370/226, 370/252, 455/67.1, 455/67.3
• US Class Current: 370/217
• CPC Class Codes: H03J 7/18 Automatic scanning over a band of frequencies
• CPC Class Codes: H04W 52/36 with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

A desirable operating condition is maintained in a communication device (100) that is operating in an undesirable environment by reducing the number of radio frequency signals being amplified and subsequently transmitted by the communication device (100). The remaining radio frequency signals transmitted will be transmitted at full power, so that coverage area is maintained in a tradeoff for reduced capacity.

Claims

1. A communication device capable of transmitting information on at least two communication channels, the communication device comprising:

a pre-transmitter section for providing at least two input signals; and

an amplifier section for amplifying the at least two input signals for transmission on the at least two communication channels, the amplifier section comprising;

at least two input ports for coupling the at least two input signals to the amplifier section;

a detector for detecting an undesirable operating condition in the communication device; and

at least one decoupler, coupled to the detector, for decoupling at least one of the at least two input signals from the amplifier section in response to the detector detecting the undesirable operating condition.

2. The communication device of claim 1, wherein the amplifier section further includes at least two exciters.

3. The communication device of claim 2, wherein each exciter comprises:

a local oscillator circuit for generating a radio frequency carrier signal; and

a mixer for mixing an input signal of the at least two input signals with the radio frequency carrier signal.

4. The communication device of claim 2, wherein the at least one decoupler is coupled to an exciter of the at least two exciters.

5. The communication device of claim 1, wherein the detector includes a heat sensor.

6. The communication device of claim 1, wherein the communication device further comprises a controller for determining input signal time slot occupancy.

7. The communication device of claim 6, wherein the controller comprises a microprocessor coupled to the detector and the at least one decoupler for selecting at least one of the at least two input signals to be decoupled from the amplifier section.

8. The communication device of claim 6, wherein the controller comprises a digital signal processor coupled to the detector and the at least one decoupler for selecting at least one of the at least two input signals to be decoupled from the amplifier section.

9. A method for protecting a multi-channel communication device in a time division multiple access communication system, comprising the steps of:

generating a plurality of input signals, each input signal occupying at least one time slot per time frame;

amplifying the plurality of input signals using at least one radio frequency amplifier to produce amplified signals;

detecting an undesirable operating condition in the communication device;

selecting at least one input signal of the plurality of input signals based on a quantity of time slots occupied in a time frame to produce at least one selected input signal; and

preventing the at least one selected input signal from being amplified in order to remove the undesirable operating condition.

10. The method of claim 9, wherein the step of detecting an undesirable operating condition in the communication device includes detecting an excessively high operating temperature of the at least one radio frequency amplifier.

11. The method of claim 9, wherein the step of detecting an undesirable operating condition in the communication device includes the failure to detect a normal operating temperature of the at least one radio frequency amplifier.

12. The method of claim 9, wherein the step of amplifying comprises the step of amplifying the plurality of input signals using at least two radio frequency amplifiers.

13. The method of claim 12, wherein the step of preventing comprises the step of decoupling at least one input signal of the plurality of input signals from at least one of the at least two radio frequency amplifiers.

14. The method of claim 12, wherein the step of preventing comprises the step of removing DC supply power from at least one of the at least two radio frequency amplifiers.

15. A method for protecting a multi-channel communication device, the method comprising the steps of:

generating at least two input signals;

amplifying, by an amplifier section, the at least two input signals to produce amplified signals;

detecting an undesirable operating condition in the communication device; and

preventing at least one of the at least two input signals from being amplified in order to remove the undesirable operating condition.

16. The method of claim 15, wherein the step of detecting an undesirable operating condition comprises the step of detecting an excessively high operating temperature of at least one radio frequency amplifier.

17. The method of claim 15, wherein the step of detecting an undesirable operating condition in the communication device comprises the step of failing to detect a normal operating temperature of at least one radio frequency amplifier.

18. A method for protecting a communication device, comprising the steps of:

generating a plurality of input signals, each input signal including user information of at least one user of a communication system containing the communication device;

amplifying the plurality of input signals;

detecting an undesirable operating condition in the communication device;

selecting at least one input signal of the plurality of input signals based on a quantity of users of the communication system having user information included in the at least one input signal to produce at least one selected input signal; and

preventing the at least one selected input signal from being amplified in order to remove the undesirable operating condition.

19. The method of claim 18, wherein the step of selecting comprises the step of selecting a first input signal of the plurality of input signals as the at least one selected input signal, wherein the first input signal includes user information of fewer users than at least a second input signal of the plurality of input signals.