Der SiRFstar IV Chipsatz
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Introducing SiRFstarIV
Architecture
with SiRFaware Technology
SiRF was founded in 1995 with the vision of bringing the benefits of GPS enabled location to mainstream consumers, and today GPS has become mainstream navigation technology. However location is more than just for navigation. Location, properly done, can enhance a broad range of services from social networking to geo-searching to geo-imaging in a variety of consumer devices – mobile phones, mobile internet devices, netbooks, notebooks, digital cameras, camcorders, gaming machines, wearable platforms, and many more. However this requires devices to be always location aware. Today’s architectures are not optimized for such environments and this is the challenge addressed with SiRFstarIVTM, an architecture that not only improves your navigation experience in smartphones, but also enables continuous location awareness in consumer devices!
Now designers no longer need to choose between continuous location awareness and battery life or depend on a network for assistance that may not be available. SiRFawareTM technology breaks the old GPS performance vs. power trade-off through the fusion of a new high-performance GPS engine, advanced power management, and a smart sensor interface to achieve high sensitivity, fast location fixes while drawing only 50-500 µA. Combined with the active jammer removal, single-SAW design, fail-safe I/O, integrated switchers, single supply voltage, simple RF matching, and small size solution, implementing the SiRFstarIV GPS receivers in a broad range of consumer devices is easier than ever.
High-speed Location Engine Twice the available DSP memory and search speed of the industry leading SiRFstarIIITM architecture for enhanced sensitivity and navigation performance, greater coverage, reduced time to fix and improved positional accuracy.
Adaptive Micropower Manager
Advanced power management with integrated switched-mode regulation to maintain hot-start conditions with minimal energy.Smart Sensor Interface
Intelligent sensor support to improve the location experience, enable greater context awareness, and open the door to superior indoor positioning accuracy.
Continuous location awareness unlocks a world of possibilities for portable consumer electronics products. The current generation of GPS-enabled products may not always be location aware because their GPS receivers are often turned off to conserve power, resulting in long start-up times.
A new level of continuous location awareness is needed to enable instant geo-tagging, LBS (Location Based Services), and location based games. But to achieve continuous location awareness in mass market devices, a location engine must deal with several design constraints:
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Mixed indoor and outdoor use>
Location with or without network aiding>
Limited power budget > Internal noise sources>
Limited board real estate > Fast, easy design cycle > Low BOM costMixed Indoor and Outdoor Use
The old operating model would switch the GPS receiver on only when necessary to get a position fix, but this compromised performance to save power, and getting a position fix indoors was often not possible.
The SiRFstar
IV architecture is optimized for how people really use location-aware products: often indoors with periods of unobstructed sky view when moving from place to place. This new architecture can detect changes in context, temperature, and satellite signals to achieve a state of near continuous availability by maintaining and opportunistically updating its internal fine time, frequency, and ephemeris data while consuming mere microwatts of battery power.
Lack of Network Aiding
Most portable consumer electronics products don’t have continuous wireless connectivity, and are typically constrained by a small battery, limited sky view, and no assistance data. Aside from handsets and smartphones in certain operator networks, even most handsets don’t have network aiding available everywhere.
The new SiRFaware self-assisted GPS mode opportunistically captures satellite fine time, frequency, and ephemeris whenever visibility improves.
Limited Power Budget
The typical design choice for powering a GPS receiver is to either turn it off until a location fix is needed—to save power, compromising location performance, or to leave the receiver on for an extended period of time, draining battery power. SiRFstar
IV architecture eliminates this trade-off via SiRFaware advanced technology features:>
Opportunistic ephemeris decode and advanced power management, allowing the GPS receiver to stay in a hot-start condition nearly continuously while consuming very little power>
Local ephemeris prediction, capturing ephemerides, and predicting them for up to three days in advance, boosting sensitivity and performance>
Dynamic contextual awareness, monitoring temperature change and available sensors to detect movement and predict sky view availability to conserve power and boost performanceInternal Noise Sources
Wireless and portable consumer electronics products are packed with a dense collection of displays, touch screens, backlights, radio transmitters and other noise sources, oftentimes located very close to the GPS antenna.
The SiRFstarIV architecture overcomes this constraint by detecting, tracking, and removing up to eight noise sources.
This feature can be used to rapidly identify issues through the design and production validation phases, and potentially as a patch in production until the jamming issues are fixed.
Limited Board Real Estate
Due to the high level of integration in SiRFstar
IV devices, as few as six external passive components plus a single SAW filter are all that’s required for a complete location solution.Fast, Easy Design Cycle
Consumer products are typically built on platforms, with many permutations for various market segments. The SiRFstar
IV architecture is robust enough to handle design variations that appear late in the development cycle.Low BOM Cost
Few external components are needed, resulting in easy integration, fast time to market, and a low BOM.
SiRFaware—the SiRFstarIV architecture’s defining feature— provides unprecedented flexibility to optimize performance and power profiles in wireless and portable consumer electronics products. To unlock SiRFaware’s full potential, the SiRFstarIV architecture includes SiRF’s new Location Manager Software Suite, host-resident software managers that help provide an extraordinary user experience. Location Manager greatly simplifies managing multiple interfaces and protocols while unlocking all the new, powerful and flexible features of the SiRFstarIV architecture, and also provides support for hybrid location solutions.
Location Manager Software Suite
Software Managers
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Context |
Energy |
Uncertainty |
MEMS |
Protocol |
Software Managers
The Context Manager determines device context—stationary, walking, running, driving, etc.—to optimize navigation performance and power management.
The Energy Manager limits power consumption to the lowest necessary for the requested position accuracy.
The Uncertainty Manager limits time and ephemeris uncertainty to maintain hot start conditions, and also monitors other environmental changes to maintain very low power consumption.
The MEMS Manager coordinates and calibrates all available sensors, selecting the best sensor for a task.
The Protocol Manager abstracts the various A-GPS protocols (SUPL, Control Plane RRC and RRLP, ASN.1 encoding/decoding) from the application, and provides a seamless interface to support multimode A-GPS session management, including multiple simultaneous sessions and more.
Design Benefits
Time to market is critical for any new product development program, requiring streamlined testing and validation capability. With the increasing complexity of location technology and standards-compliance, however, the design and validation effort can be substantial.
The SiRF Location Manager Software Suite offers product designers a choice of pre-integrated solutions, enabling reduced overall program costs. The extensible software suite scales to support several product variants, streamlining the design and validation process. The Location Manager Suite can also be used to test hybrid location capability at the platform validation phase before specific productization.
With standardized location APIs, the Location Manager Suite enables the developer community to benefit from fast development, integration, and testing. Coupling built-in, standards-compliant protocol and session managers with the architecture’s significant 3GPP assisted GPS pass margins, launching an A-GPS device is easier and faster than ever.
In 1995 SiRF was founded on the belief that all mobile and portable products would be location enabled if the location technology could be dramatically improved. The SIRFstarIITM architecture significantly improved urban canyon navigation accuracy and performance. The SIRFstarIII architecture improved sensitivity and time to first fix so much that it became the industry benchmark for portable wireless phones and navigation products. The new SiRFstarIV architecture sets a new standard for performance with breakthrough ultra-low power consumption.
On 26 June 2009, SiRF and CSR merged, creating a leading pure play provider of connectivity and location platforms to enable its customers to address the exciting opportunities in mobile markets.
