Power control in 3G terminals

March 14, 2011 // By Jim Nohrden
Jim Nohrden, Black Sand's VP of Marketing, examines how to tame the three conflcting design goals facing the power control system of a modern mobile device.

We have moved into the “Fourth Wave of Computing”.  One where computation is less about raw horsepower and more about connectivity and power efficiency.  In other words, we are moving from the era of PCs and into the era of smartphones and tablets.  This transition will take us to an ever more intuitive and interactive experience with our electronic devices.  From mobile apps to augmented reality, the next generation of computation devices are wirelessly-connected and always on.

Our everyday lives are becoming more dependent on these next generation devices and we expect them to be reliable and connected at all times.  Advanced wireless standards such as WCDMA, WiFi, and LTE ensure that our products are interoperable with each other and around the world.  We rely on these standards to ensure the robust operation of the mobile products we own.

Balancing TRP, SAR, and ID

In order to provide products that are reliable, fun to use and safe, mobile device designers strive to create products that first can achieve high total radiated power (TRP).  Consumers want devices with elegant industrial design (ID) and hidden antennas, all while simultaneously not violating radiated safety limits, measured as SAR (specific absorption rate).  Balancing these three conflicting goals is no simple task for mobile device designers.

Wireless operators would prefer to see mobile devices with the highest TRP, ensuring the highest data rates and fewest dropped calls.  Consumers make the buying decision based on other factors such as software interface and great ID.  At the same time, government safety regulators must ensure that wireless devices in the market err on the side of safely, limiting wireless SAR emissions that are considered harmful, but possibly also limiting TRP.

A factor affecting these three design goals is the power control system of a mobile device.  In 3G WCDMA and CDMA communications systems, very tight control of mobile device power is also required in order to ensure

Design category: