Time based signal detector for operating in a presence search mode and absence search mode during peak times and off peak times

• US 5,140,702 A
• Filed: 06/05/1990
• Issued: 08/18/1992
• Est. Priority Date: 06/05/1990
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Laflin, Timothy C.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Charouel, Lisa D.
• Application Number:
  US07/534,587
• Time in Patent Office: 805 Days
• Field of Search: 455/161, 455/166, 455/343, 455/229, 455/167, 455/296, 455/231, 455/181, 455/222, 455/67, 340/825.44, 340/825.47, 340/825.40, 340/311.1
• US Class Current: 455/166.1
• CPC Class Codes: H04L 7/0338 the correction of the phase error being performed by a feed forward loop
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0248 dependent on the time of the day, e.g. according to expected transmission activity
• CPC Class Codes: H04W 88/026 using digital address codes
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A receiver capable of receiving a plurality of signals, wherein more of the signals are received at a peak time than at an off peak time, comprises the method of a first step for determining if the signals are being received by searching in a first search mode and a second step for determining if the signals are not being received by searching in a second search mode. Selection circuitry activates the first step during the peak time and activates the second step during the off peak time. The first and second search modes comprise searching for the signal and searching for noise, respectively.

Claims

1. An apparatus comprising:

a receiver capable of receiving a plurality of signals, wherein more of the signals are received at a peak time than at an off peak time;

first means for determining if the signals are being received by searching in a first search mode;

second means for determining if the signals are not being received by searching in a second search mode; and

third means for activating the first means during the peak time and activating the second means during the off peak time.

2. The apparatus according to claim 1 wherein the third means for activating comprises fourth means for comparing the current time with a predetermined time for defining the peak time and off peak time.

3. The apparatus according to claim 1 wherein the third means comprises fourth means for storing information regarding whether the receiver is synchronous to the signals received during each of a plurality of time periods, wherein the peak time comprises the time periods when the receiver is synchronous more than fifty percent of the time periods.

4. In a receiver capable of receiving a plurality of signals, wherein more of the signals are received at a peak time than at an off peak time, the method comprising the step of selecting a signal present search mode during the peak time and a signal absent search mode during the off peak time, wherein the peak time is determined by the steps of:

(a) determining whether the receiver is synchronous to the signals received during each of a plurality of time periods;

(b) storing information in response to an affirmative determination of step (a) indicating the peak time for the time periods; and

(c) storing information in response to a negative determination of step (a) indicating an off peak time for the time periods.

5. An apparatus comprising:

a receiver capable of receiving a plurality of signals, each signal having transitions between first and second states occurring at a predetermined baud rate, wherein more of the signals are received at a peak time than at an off peak time;

first means for determining if the signals are being received by searching for the signal having the predetermined baud rate;

second means for determining if the signals are not being received by searching for noise; and

third means for activating the first means during the peak time and activating the second means during the off peak time.

6. The apparatus according to claim 5 wherein the third means for activating comprises fourth means for comparing current time with a predetermined time for defining the peak time and off peak time.

7. The apparatus according to claim 5 wherein the third means comprises fourth means for storing information regarding whether the receiver is synchronous to the signals received during each of a plurality of time periods, wherein the peak time comprises the time periods when the receiver is synchronous more than fifty percent of the time periods.