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
Jul 12, 2024
I'm having olfactory flashbacks to the strangely satisfying scents found in machine shops. I love the smell of hot oil in the morning....

featured video

Larsen & Toubro Builds Data Centers with Effective Cooling Using Cadence Reality DC Design

Sponsored by Cadence Design Systems

Larsen & Toubro built the world’s largest FIFA stadium in Qatar, the world’s tallest statue, and one of the world’s most sophisticated cricket stadiums. Their latest business venture? Designing data centers. Since IT equipment in data centers generates a lot of heat, it’s important to have an efficient and effective cooling system. Learn why, Larsen & Toubro use Cadence Reality DC Design Software for simulation and analysis of the cooling system.

Click here for more information about Cadence Multiphysics System Analysis

featured paper

DNA of a Modern Mid-Range FPGA

Sponsored by Intel

While it is tempting to classify FPGAs simply based on logic capacity, modern FPGAs are alterable systems on chips with a wide variety of features and resources. In this blog we look closer at requirements of the mid-range segment of the FPGA industry.

Click here to read DNA of a Modern Mid-Range FPGA - Intel Community

featured chalk talk

Power Gridlock
The power grid is struggling to meet the growing demands of our electrifying world. In this episode of Chalk Talk, Amelia Dalton and Jake Michels from YAGEO Group discuss the challenges affecting our power grids today, the solutions to help solve these issues and why passive components will be the heroes of grid modernization.
Nov 28, 2023
29,160 views