Dismiss
InnovationQ/InnovationQ Plus content will be updated on Sunday, June 25, 10am ET, with new patent and non-patent literature collections. Click here to learn more.
Browse Prior Art Database

HIGH EFFICIENCY BATTERY SAVER FOR PL AND CARRIER SQUELCH RADIOS

IP.com Disclosure Number: IPCOM000006750D
Original Publication Date: 1993-Mar-01
Included in the Prior Art Database: 2002-Jan-29
Document File: 2 page(s) / 116K

Publishing Venue

Motorola

Related People

Hunh-Weng Khoo: AUTHOR

Abstract

In scme radios, a battery saver mode for PL was not enabled due insignificant current savings. The sleep period was only 60 msecs and the active time was about 450 msecs. The battery save period is about 12%. This figure was not optimal and could be improved to 84% and more.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 50% of the total text.

Page 1 of 2

MOTOROLA INC. Technical Developments Volume 18 March 1993

HIGH EFFICIENCY BATTERY SAVER FOR PL AND CARRIER SQUELCH RADIOS

by Hunh-Weng Khoo

INTRODUCTION

  In scme radios, a battery saver mode for PL was not enabled due insignificant current savings. The sleep period was only 60 msecs and the active time was about 450 msecs. The battery save period is about 12%. This figure was not optimal and could be improved to 84% and more.

  For a carrier squelch channel, the sleep period was 100 msecs and the active period was 80 msecs. The battery save period was about 56%. The 80 msecs was due to the software sampling squelch logic out for a fvted amount of time before going to sleep again. This figure was also not optimal and could be improved to 84% or more.

  The radio also suffered the loss of the lirst few spoken syllables due to longer PL detect time during battery saver. This prroblem was dependent on when the PL signal appeared and sometimes the radios needed two active PL decode periods to get a PL detect. This is a serious problem as "no shoot" could be received as "shoot?

  Another problem the radio had was that PL detect sensitivity degraded by 2 dBm when battery saver was enabled.

A SCHEME TO IMPROVE

BATTERY SAVER EFFICIENCY

  It is proposed that whenever carrier is present, PL decoder will not be enabled if the current PL transmit- ted has been found to be different from the channel pro- grammed PL. This will shorten the active period and improve the battery saver sleep effZency. In order for this scheme to work, it should be implemented as fol- lows: When the carrier is first detected on a channel, the PL decoder will be activated for 800 msecs (EEPROM programmable if desired). If there is no PL detect on this channel at the end of 800 msecs, the radio will

60

re-enter battery saver mode immediately. PL decode will be locked for this channel until carrier disappears and re-appears. When the radio wakes up from sleep and the carrier is still present but with PL decode locked out, the radio will re-enter battery saver immediately. Consequently, the amount of active time is minimized to 20 msecs due to hardware settling times and RF car- rier detect. Since the sleep,period is 100 msecs, the sleep efficiency is improved to 84%. This is a seven-fold time improvement over the old scheme. The sleep efficiency is of course increased if sleep period is increased.

  The PL decoder will'be unlocked when the radio gets out of battery saver and finds that there is no car- rier. When the carrier appears again, the sequence described above repeats itself.

  In order to make a quick decision about the pres- ence or absence of the cariier, the CA1 line which acts as a quick RF carrier indic&r is used. If the CA1 line is high for 3 consecutive samples, the RF carrier is con- sidered detected. Otherwise, the carrier is not detected. Since the s...