editor's blog
Subscribe Now

MIMO: Hardware or Software?

A while back we covered CEVA’s move to multicore for their communications-oriented XC architecture. One of the motivating elements was the complexity of requirements for features like MIMO, the ability to use more than one antenna – and multiple channels formed by the product of the number of sending and receiving antennas. They say that using a software approach provides the flexibility needed for the variety of options, that there are too many differences between options to implement in hardware: there would be too much unshared hardware, and it would be inefficient.

Sounds reasonable. But then came a completely separate announcement from Quantenna. They’re also doing MIMO, but in hardware. They can handle up to 4×4 MIMO (that is, 4 antennas sending, 4 receiving; 16 channels). And they say that it’s not reasonable to expect to be able to meet the performance requirements without doing it in hardware.

Both companies seem to agree on the complexity of the standards they’re implementing. The thing about such WiFi communication is that the environment is constantly changing, and you have to constantly re-evaluate which channels are working best and where to send things. This re-optimization is checked every 100 ms.

In fact, Quantenna says that, if the radar band is unpopulated, it can also be used, although they claim that most boxes don’t take advantage of this, remaining within the crowded non-radar portion, even though the radar portion has the bulk of the available bandwidth.

There is also beam-forming to be done – including “blind” beam-forming, where only one end of the channel can do it. Channel stability has to be rock solid since there’s no buffering for streaming video. Equalization has to be optimized. And in a higher layer, there’s quality-of-service (QoS) for video.

And most of this isn’t established at design time; it’s a constant real-time re-jiggering of parameters to keep things working as efficiently as possible. And it has to work alongside the earlier 802.11n and below standards. And Quantenna says they can handle all of this in hardware, without blowing the silicon budget.

You can imagine that being able to do it in software might be quite convenient and space-efficient. You can also imagine that hardware would provide much higher performance. So which is best?

Rather than get into the middle of adjudicating this myself, I offer both sides the opportunity to state their cases in the comments below. And any of the rest of you that have something constructive to contribute to the discussion, please do.

Meanwhile, you can get more details on Quantenna’s announcement in their release.

Leave a Reply

featured blogs
Dec 2, 2024
The Wi-SUN Smart City Living Lab Challenge names the winners with Farmer's Voice, a voice command app for agriculture use, taking first place. Read the blog....
Dec 3, 2024
I've just seen something that is totally droolworthy, which may explain why I'm currently drooling all over my keyboard....

Libby's Lab

Libby's Lab - Scopes Out Silicon Labs EFRxG22 Development Tools

Sponsored by Mouser Electronics and Silicon Labs

Join Libby in this episode of “Libby’s Lab” as she explores the Silicon Labs EFR32xG22 Development Tools, available at Mouser.com! These versatile tools are perfect for engineers developing wireless applications with Bluetooth®, Zigbee®, or proprietary protocols. Designed for energy efficiency and ease of use, the starter kit simplifies development for IoT, smart home, and industrial devices. From low-power IoT projects to fitness trackers and medical devices, these tools offer multi-protocol support, reliable performance, and hassle-free setup. Watch as Libby and Demo dive into how these tools can bring wireless projects to life. Keep your circuits charged and your ideas sparking!

Click here for more information about Silicon Labs xG22 Development Tools

featured chalk talk

ROHM’s 3rd Gen 650V IGBT for a Wide range of Applications: RGW and RGWS Series
In this episode of Chalk Talk, Amelia Dalton and Heath Ogurisu from ROHM Semiconductor investigate the benefits of ROHM Semiconductor’s RGW and RGWS Series of IGBTs. They explore how the soft switching of these hybrid IGBTs contribute to energy savings and power generation efficiency and why these IGBTs provide a well-balanced solution for switching and cost.
Jun 5, 2024
33,771 views