Power Efficient Software Defined Radio (SDR) Mobile Architecture Technology for Handheld Devices

ABSTRACT: To meet the demands of next generation military GPS handsets, as well as growing commercial demand for low-power GPS, we propose a GNSS baseband receiver that is flexible for both current and new waveforms, and highly energy efficient. We achieve flexibility through the design of a programmable spreading code generator that is highly compact, yet able to generate all publicly known GPS and Galileo waveforms. Careful attention is also paid to the acquisition and tracking modules to ensure they can handle variable sample and integration rates, as well as newer modulations such as BOC. We achieve energy efficiency through the use of ultra-low voltage operation. Using recently established design principles that allow circuits to operate at voltages near the threshold voltage, along with parallelization of the on-chip microprocessors and baseband circuitry, we plan to demonstrate a receiver that consumes orders of magnitude less power than current flexible receivers. Special attention is paid to the acquisition module, which must be able to acquire long-coded military signals, while consuming very little power. We propose using a newly developed style of ultra-low voltage asynchronous logic to produce such a module. BENEFIT: Of all of the military technology that has dual civilian and commercial use, GPS is perhaps the most successful. It is now being used in a wide variety of commercial applications, has already become a multi-billion dollar industry, and has spawned additional GNSS constellations from other counties. The technology proposed in this project is useful for almost all applications that use GPS. For surveying equipment, there is a desire not only to reduce the power consumption of the equipment and lighten the load, but also support multiple constellations and frequencies, which can greatly increase measurement accuracy. For asset tracking and shipping, ultra-low power portable GPS tags that can store and communicate their location real-time would ensure that freight and critical assets are never lost. Every day users of cell phones can even benefit: almost everyone who has ever used a smartphone's GPS functionality notices how the device heats up and the battery drains quickly. By accomplishing our objectives, we can produce a baseband and navigation processor that can greatly lower the power consumption of global navigation, which will make these applications more feasible, and open the door to new ones.