C3.4 - Considerations for Effective Low Power Wirless Sensor Systems in Industrial Environments
- SENSOR+TEST Conferences 2011
2011-06-07 - 2011-06-09
- Proceedings SENSOR 2011
- C3 - Wireless Sensors II
- M. Grazier - Texas Instruments, Nashua, New Hampshire (USA), T. Almholt - Texas Instruments, Dallas, Texas (USA)
- 423 - 438
This paper addresses key considerations for enabling robust low power wireless sensor links for use in large scale industrial settings.Applications include large, multi-story buildings that have complicated layouts and use building materials such as metal, reinforced concrete, and corrugated metal plates which are not friendly to RF communication systems. We will review wireless communication theory and discuss how to enable robust and reliable communication in these types of environments. We will review a generic RF communication channel and then offer techniques to limit or eliminate typical intereferers to radio systems.
We will begin by the reviewing most frequently observed impairments in a radio channel. Next we will present techniques to combat each of these impairments. Then we will discuss the importance of radio performance parameters such as channel selectivity, alternate and adjacent channel rejection, robust signal synchronization and good receiver sensitivity using best practice radio modulation such as FSK(frequency shift keying) or DSS(direct sequence spectrum).
We will proceed to the typical system level techniques to improve radio performance like CSMA ( listen before talk), automatic acknowledgments, receive signal strength indicators, antenna diversity and forward error correction. We will conclude with a discussion of how advanced transceiver functionality and fast RF settling times enable ultra low power wireless sensors to be powered by energy harvesters for solar cells and piezo electrics devices.