editor's blog
Subscribe Now

Microsemi Moves GNSS Indoors

Much of the cellular build-out in areas that already have coverage is happening through small cells. It’s like we’ve gotten the broad brush strokes in place; now we’re fine-tuning coverage and capacity here and there as needed.

And much of this is happening in buildings – malls, office buildings, and other areas where large numbers of people concentrate.

Which creates a problem: these cells rely on accurate timing from GPS (or GNSS, generically). And, as we’ve seen in our discussions of indoor navigation, GPS isn’t a thing indoors. At least, not for your average receiver.

So what happens is, well, exactly what you’d expect: you put an antenna on the building to receive the GPS signal. That involves getting power up there and then distributing the received signal via coax.

That might not seem like much of a burden for those of you accustomed to setting up a TV satellite dish for your home. But, apparently, this is a bigger deal with big buildings. Running those bulky, shielded wires around isn’t trivial. And, apparently, the operator may even have to rent the space on the roof where the antenna goes. Oi, everyone with their hand out!

So Microsemi has come up with an alternative. They call it an integrated GNSS master – IGM. It will provide the master timing signal for the small cells installed in the building. It’s designed to be installed indoors.

“But there is no GPS signal indoors,” you might reasonably protest. Well, apparently there is – it’s just not a strong signal. (OK, I’m sure you can find places where the signal is pretty much gone. So… yeah, the Panic Room is probably not a good place to mount this. Although… read on…) How do they capture this signal?

First, they have a very sensitive receiver. They also take advantage of assisted GNSS (A-GNSS). That covers a broad range of alternative ways of receiving GNSS signals. Some are sent by Ethernet; some are pre-calculated and sent ahead of time; etc. Together, through what we might call “signal fusion” (by analogy with sensor fusion) with whatever live GPS signal it can detect, these allow the IGM to function indoors. It also improves the time-to-first-fix.

“But you still have to route power and signals,” you might continue to protest. Well, yes and no. There’s no clunky coax: it’s Ethernet. And the unit leverages Power over Ethernet (PoE). So once you’ve plugged the Ethernet cable in, you’re good to go. Much easier to wire; no conduit or high voltages to muck about with.

Microsemi_Integrated_GNSS_Master-IGM-Diagram_cr.jpg 

(Image courtesy Microsemi)

Thinking ahead, could this be leveraged for indoor navigation? That’s not Microsemi’s immediate plan, but they say that, in principle, it could.

You can read more in their announcement.

Leave a Reply

featured blogs
Jan 26, 2022
With boards becoming more complex and lightweight at the same time, designing and manufacturing a cost-effective and reliable PCB has assumed greater significance than ever before. Inaccurate or... [[ Click on the title to access the full blog on the Cadence Community site. ...
Jan 26, 2022
PCIe 5.0 designs are currently in massive deployment; learn about the standard and explore PCIe 5.0 applications and the importance of silicon-proven IP. The post The PCI Express 5.0 Superhighway Is Wide, Fast, and Ready for Your Designs appeared first on From Silicon To Sof...
Jan 24, 2022
I just created a handy-dandy one-page Quick-Quick-Start Guide for seniors that covers their most commonly asked questions pertaining to the iPhone SE....

featured video

AI SoC Chats: Understanding Compute Needs for AI SoCs

Sponsored by Synopsys

Will your next system require high performance AI? Learn what the latest systems are using for computation, including AI math, floating point and dot product hardware, and processor IP.

Click here for more information about DesignWare IP for Amazing AI

Featured Paper

EV Kit for ADI’s nanoPower 300nA Quiescent Current, Synchronous Step-up DC-DC Module

Sponsored by Analog Devices

Learn how to use the MAXM17225 EV kit with detailed procedure and circuit connections to test the MAXM17225’s functionality. Some of the features of the ev kit include a 0.4V to 5.5V input range, a 1.8V to 5V resistor selectable output voltage, and 1A peak inductor current limit.

Find Out More

featured chalk talk

Machine-Learning Optimized Chip Design -- Cadence Design Systems

Sponsored by Cadence Design Systems

New applications and technology are driving demand for even more compute and functionality in the devices we use every day. System on chip (SoC) designs are quickly migrating to new process nodes, and rapidly growing in size and complexity. In this episode of Chalk Talk, Amelia Dalton chats with Rod Metcalfe about how machine learning combined with distributed computing offers new capabilities to automate and scale RTL to GDS chip implementation flows, enabling design teams to support more, and increasingly complex, SoC projects.

Click here for more information about Cerebrus Intelligent Chip Explorer