Re: [Discuss-gnuradio] (GSoC) MIMO stuff in GNU Radio

[YiZiRui Zhou]

On Thu, Feb 20, 2014 at 11:10 PM, Michael Dickens <address@hidden> wrote:

Hi Zhou - I think it would be great to see how far GNU Radio can be pushed with respect to MIMO processing.  With advances in both algorithms and multi-core CPU raw processing capabilities, the added computational requirements for MIMO might be realizable at some reasonable level (IIRC, they were not [for commodity processors] back in 2007-2009 when I looked into this last).  I agree that MIMO is in wireless networking's future; the big question is how much anyone can accomplish in a few month's work towards getting even a basic MIMO system working (within GNU Radio, in this case; but, really, any platform that does not already provide such capabilities).

Your paper / research links are fine, though there must be a few more which are more seminal works on "how to do practical MIMO" which are concise and basic.

SORA is a non-starter for many researchers; compare the number of papers on or using SORA to those using GNU Radio ...

The GR GSoC14 website is < http://gnuradio.org/redmine/projects/gnuradio/wiki/GSoC > and I encourage you to add your proposal to the "Signal-Processing" section.  I think you should be concise yet complete and realistic in what you think you can accomplish in a few months of work on this topic -- for example, you're not going to be able to implement 802.11n but you can probably come up with some basic MIMO using OFDM PHY layer concepts which would prove useful and interesting (taking in multiple data streams, then using MIMO to do encoding, then Tx them to a receiver, which does Rx, decoding, and pushing out multiple data streams; with or without feedback).  MIMO can be very complicated, so I'd encourage you to keep the scope reasonable (yet truly MIMO).  Let me / the list know when your part is up. - MLD

On Feb 20, 2014, at 9:39 AM, YiZiRui Zhou <address@hidden> wrote:
> Glad to hear from you.
>
> To be frank, MIMO is not a novel thing, since it has been proposed for many years. In the past, most research on MIMO stay in theory due to the limitation of signal processing technology. But things are different now. Since 2009, when IEEE passed the 802.11n draft, study on practical MIMO surges. Now, it becomes more prevalent.
>
> There are many research papers on MIMO, many of them are published in Mobicom or Sigcomm, which are all top conferences on Computer Network.
>
> Among them, I think "802.11 with multiple antennas for dummies" is a good guide for someone who are not so familiar with practical MIMO systems. This is the link.
>
> http://homes.cs.washington.edu/~dhalperi/pubs/mimo_for_dummies.pdf
>
> A paper "Rate adaptation for 802.11 multiuser mimo networks" implement MIMO with GNU Radio and USRP, but it focus on uplink transmission only. Also, the details on how to build MIMO systems with USRP is not illustrated, maybe you will be interested on how it works too. This is the link.
>
> https://homes.cs.washington.edu/~gshyam/Papers/turborate.pdf
>
> Other works are not list here for brevity. By the way, some studies on MIMO are based on Sora, another SDR platform.
>
> http://research.microsoft.com/en-us/projects/sora/
>
> In my opinion, MIMO systems will be more ubiquitous in the future. But it seems that there is no relevant standard block (gr-mimo) to achieve this in GNU Radio yet. So I think maybe there is something I can do.

Hi Michael,

As you said, although there is a pile of research papers on MIMO, tutorials and examples on how to build MIMO system are limited. Many researchers are not willing to release their source codes for the sake of maintaining secrecy. But there do exist some works on building practical MIMO systems, I will try to get these ready.

When the preparation gets done, I will try to add my proposal to the GR GSoC website in the following weeks and keep in touch with you / the list. Wish to get valuable advice from you.

Thanks for your encouragement.

Zhou