Communication system with adaptive transceivers to control intermodulation distortion

• US 5,001,776 A
• Filed: 10/27/1988
• Issued: 03/19/1991
• Est. Priority Date: 10/27/1988
• Status: Expired due to Fees

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Clark, Edward T.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Urban, Edward
• Application Number:
  US07/263,146
• Time in Patent Office: 873 Days
• Field of Search: 455/295, 455/296, 455/308, 455/309, 455/310, 455/311, 455/255, 455/256, 455/264, 455/235, 455/236, 455/343, 455/226, 455/67, 455/68, 455/88
• US Class Current: 455/226.2
• CPC Class Codes: H04B 1/109 by improving strong signal performance of the receiver when strong unwanted signals are present at the receiver input

Abstract

A transceiver determines the signal quality of a desired signal and the strength of all received signals. When the signal quality of the desired signal is low, and the signal strength of all received signals is high, the receiver is adapted to operate in a higher current mode, thereby minimizing intermodulation distortion. Conversely, when the quality of the desired signal is low and the strength of all received signals is also low, or when the quality of the desired signal is above a threshold, the receiver operates in a lower current mode to conserve power and maximize battery lifetime. Also, when the transceiver adapts to operate in the higher current mode, a command is sent instructing a transmitting party to increase the quality of their message which may enable the listening transceiver to adapt (return) to a lower current mode.

Claims

1. In a two-way radio frequency communication system having at least two transceiving devices, a method for receiving an information signal that may be corrupted by an interfering signal, comprising the steps of:

in at least one transceiving device;

(a) receiving a signal to provide a received signal comprising at least a desired signal;

(ai) mixing the received signal with an injection signal to provide a mixed signal;

(b) determining whether said desired signal has a signal quality above a first threshold after the received signal has been mixed;

(c) determining whether said received signal has a signal strength above a second threshold before the received signal is mixed; and

(d) controlling intermodulation distortion by adjusting at least said injection signal when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold;

(e) transmitting a command code when said signal quality of said desired signal is below said first threshold and said strength of said received signal is above said second threshold;

(f) determining whether said desired signal has a signal quality above a first threshold;

(g) adjusting at least said injection signal when said signal quality of said desired signal is above said first threshold.

2. The method of claim 1, wherein step (d) comprises increasing peak voltage of said injection signal when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold.

3. The method of claim 2, wherein step (d) further comprises reducing rise time of said injection signal when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold.

4. The method of claim 1, wherein step (d) comprises reducing rise time of said injection signal when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold.

5. The method of claim 1, wherein step (d) comprise adjusting at least a portion of said receiver to operate in a higher current mode when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold.

6. The method of claim 5, wherein step (d) further comprises adjusting said receiver to operate in a lower current mode when said signal quality of said desired signal is above said first threshold.

7. In a two-way frequency communication system having at least two transceiving devices, a method for receiving an information signal in the presence of an interfering signal, comprising the step of:

in a first one transceiving device;

(a) a receiving a signal to provide a received signal comprising at least a desired signal;

(b) determining whether said received signal has a signal strength above a second threshold before mixing an injection signal with said received signal;

(c) determing whether said desired signal has a signal quality above a first threshold after mixing said injection signal with said signal; and

,

(d) controlling intermodulation distortion by adjusting at least said injection signal when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold;

(e) transmitting a command code when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold;

(f) determining whether said desired signal has a signal above a first threshold;

(g) adjusting at least said injection signal when said signal quailty of said desired signal is above said first threshold;

at a second transceiving device;

(a) transmitting said desired signal;

p1 (b) receiving said command code;

(c) adjusting said second transceiving device and/or said desired signal in response to receiving said command code; and

(d) transmitting said desired signal.

8. The method of claim 7, wherein step d further comprises adjusting at least a portion of said receiver to operate in a higher current mode when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold.

9. The method of claim 7, wherein step (e) further comprises adjusting said receiver to operate in a lower current mode when said said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold.

10. In a two-way radio frequency communication system having at least two battery powered transceiving devices having at least one converter capable of mixing a received signal with an injection signal to facilitate recovery of an information signal, a method for controlling intermodulation distortion in the battery powered transceiving devices comprising the steps of:

in a first transceiving device;

(a) receiving a signal to provide a received signal comprising at least a desired signal;

(b) determining whether said desired signal has a signal quality above a first threshold after mixing said received signal with an injection signal;

(c) determining whether said received signal has a signal strength above a second threshold before mixing said received signal with said injection signal; and

(d) controlling intermodulation distortion by adjusting at least said injection signal when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold;

(e) transmitting a command code when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold;

(f) determining whether said desired signal has a signal quality above a first threshold;

(g) adjusting at least said injection signal when said signal quality of said desired signal is above said first threshold;

at a second transceiving device;

(a) transmitting said desired signal;

(b) receiving said command code;

(c) adjusting said second transceiving device and/or said desired signal in reponse to recieving said command code; and

,

(d) transmitting said desired signal.

11. A radio frequency transceiving device capable of receiving an information signal that may be corrupted by an interfering signal, comprising:

means for receiving a signal to provide a received signal comprising at least a desired signal;

means for filtering said received signal to substantially provide said desired signal;

means for determining whether said desired signal has a signal quality above a first threshold after the received signal is filtered to provide said desired signal;

means for determining whether said received signal has a signal strength above a second threshold before the received signal is filtered to provide said desired signal; and

,

means for controlling intermodulation distortion by adjusting at least an injection signal when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold; and

,

means for transmitting a command code when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold.

12. The radio frequency receiver of claim 11, wherein said means for controlling comprises means for increasing peak voltage of said injection signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold.

13. The radio frequency receiver of claim 12, wherein said means for controlling further comprises means for reducing rise time of said injection signal when said signal quality of said desired signal is below said first threshold and said signal strength of said received siganal is above said second threshold.

14. The radio frequency receiver of claim 11, wherein said means for controlling further comprises means for reducing rise time of said injection signal when said signal of said desired signal is below said first threshold and said signal strength of said received siganal is above said second threshold

15. The radio frequency receiver of claim 11, which includes means for adjusting at least a portion of said receiver to operate in a higher current mode when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold.

16. The radio frequency receiver of claim 15, which includes means for adjusting said receiver to operate in a lower current mode when said signal quality of said desired signal is above said first threshold,

17. A battery powered radio frequency transceiver for use in a two-way radio frequency communication system having at least two of said battery powered radio frequency transceivers each having at least one convertor for receiving an injection signal and a received signal to facilitate recovery of an information signal that may be corrupted by an interfering signal, and each of said at least two battery powered radio frequency transceivers being capable of controlling intermodulation distortion by adjusting between a low current mode and a high current mode which includes adjusting at least the peak voltage and rise time of said injection signal, said battery powered radio frequency transceiver comprising:

a battery source;

means for receiving a signal to provide a received signal comprising at least a desired signal;

means for mixing said received signal to substantially provide said desired signal;

means for determining whether said desired signal has a signal quality above a first threshold after mixing said received signal;

means for determining whether said received signal has a signal strength above a second threshold before mixing said received signal; and

,

means for controlling intermodulation distortion by adjusting at least an injection signal when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold; and

,

means for transmitting a command code when said signal quality of said desired signal is below said first threshold and said signal strength of said received signal is above said second threshold.