What is Beamforming? ("the best explanation I’ve ever heard")

[@trentwashington9648]

Best. Explanation. Period.

[@Dan-qp1el]

Period.

[@northmirko]

Period.Period.

[@ethancooper4154]

Here I am, in my first hardware engineering job for digital audio devices, coming back to the same channel that got me through my first signals and systems class as a sophomore in college. Quality translates, folks! Iain rocks!!!

[@iain_explains]

That's awesome to hear! Thanks for your comment. Good luck in your job. It's always exciting to hear from people starting their careers in industry.

[@officiallounge]

Words are not enough to express how grateful I am to have encountered this channel. Thank you again dear Iain for sharin your knowledge

[@iain_explains]

Thanks for your very nice comment. It's great to hear that you like the videos.

[@PradeepReddy-v9q]

Hands down, the best explanation of Beamforming concept , so far across the internet. Hope the LLMs train on content like these to cater for future generations. Thanks a lot Iain ! Please dont stop making more videos.

[@iain_explains]

Glad you liked it!

[@ainguyensy6006]

That's exactly "the best explanation I've ever heard". Thank you sir!

[@iain_explains]

Glad it was helpful!

[@MAV3NX]

Solid Gold. Like Einstein said, if you can't explain it simply, you don't understand it enough. What a concise visual representation of the basics of beamforming.

[@iain_explains]

Thanks for your nice comment. I'm glad you like the video.

[@ravikantsjadhav]

Superb explaination with great example. Now I also understood how Beamforming Microphones work in my headphones. Thank you!!

[@iain_explains]

Glad it was helpful!

[@irfan_antennas]

Watched 2 times and understood it like nothing else. It is the best explanation.

[@iain_explains]

I'm so glad it helped. And I'm glad you found it useful to watch a second time. I've always tried to put details into my videos, alongside the overall explanations, that will give people extra benefits if they watch the videos multiple times.

[@tianyouhu5973]

Before watching your video I’ve been reading a lot of blog introducing what is beamforming, but I still cannot understand it. Your illustration is so easy to understand. Thank you Sir!

[@iain_explains]

I'm glad you found it useful.

[@JuanMrDude]

It's amazing how good your videos are. With just pen and paper you have made me understand so many concepts! Thank you so much for your contribution.

[@iain_explains]

I'm so glad you like the videos and the format!

[@kloroformd]

It's like noise cancellation headphones. But instead of subtracting by having a reversed waveform, it adds. And just like good noise cancelling headphones, it has to know the distance between the microphones and earpieces.

[@leeamiellina9855]

Clear explanation sir. thank you

[@dcpotomac20850]

I have a master degree in EE, this is the best explanation of beam forming I have seen without all the fancy equations.

[@iain_explains]

I'm glad you liked the explanation.

[@LTEVideoTutorials]

I watched many videos on this topic, but only this video made me visualise the beam forming. Thanks for making such a complicated topic so easy :)

[@iain_explains]

Glad it helped!

[@bobbaberson3654]

Dear Iain, these are all amazing videos. It is really tough to condense such complex material into short videos but maintain understandability of the it. This is really appreciated. You mentioned radar a couple of times. Do you have any plans to make a basic lecture on that? Maybe just simple doppler/ToF/AoA extraction or maybe something on MUSIC algorithm. I have been searching for a while for a decent explanation of MUSIC but it is hard to find one.

[@iain_explains]

I'm glad you like the videos. Thanks for the suggestion of a radar and MUSIC topic video. I'll add it to my "to do" list.

[@iain_explains]

... I just came across this comment again. I've now made a few videos on Radar, and plan to make more. I guess you may have seen them by now, but if not, then the ones I've done so far are: "Why is a Chirp Signal used in Radar?" kzbin.info/www/bejne/gKrRoGB4lsSfgdU , "What is a Stepped Frequency Radar Signal?" kzbin.info/www/bejne/bHu5eJVpgNWJp9U and "How does a Radar Track Manoeuvring Targets?" kzbin.info/www/bejne/n5PZnX6KfLZnsLM

[@sivasenthilkumaranmuthusam5552]

One of the best explanations of beam forming ..

[@iain_explains]

Glad you liked it

[@pinec0ne]

I had so many "aha!" moments during this video that I ended up liking it multiple times, from going to click the "Like" button, forgetting that I had already liked the video just a few minutes before. Great explanation!

[@iain_explains]

Thanks. I'm so glad you found the video helpful.

[@wunxue]

This explain is intuitive and clear. Excellent job.

[@iain_explains]

Glad it was helpful!

[@sajjadahmad8339]

can't be explained better than this, so clear.

[@iain_explains]

Thanks for your comment. I'm glad you liked it.

[@slimjim3921]

Trying to wrap my head around this topic all day, caught your video and boom, mind blown... THANK YOU!

[@iain_explains]

Fantastic! I'm so glad it helped.

[@zahrazarei6858]

Thanks. It was awesome as I watched it for the second time. In practice, how are these delays adjusted and how do we know (in the receiver) which direction is the direction of interest to adjust those delays? Same question for transmit beamforming.

[@iain_explains]

I've got a video coming out on Monday that gives the equation that relates the direction to the delays. Keep an eye out for it.

[@zahrazarei6858]

@iain_explains Thank you so much. Definitely will be so helpful as always

[@adarshiyer8244]

I haven't seen a better explanation for this.. hats off sir

[@iain_explains]

Thanks. I'm glad you liked it.

[@hzmaomao0307]

The most intuisive explaination that I've ever seen!

[@iain_explains]

I'm so glad it was helpful.

[@fifaham]

Thank you Iain. Beam forming is an Amazing principle. So by adding multiple antennas (n Antennas) and injecting a delay circuits and adders we can form those shaped zones and select which receiver to have the best reception from specific direction. I imagine that if we have a programmable delay circuits with algorithm to control those delays and selecting the proper antennas then we can control those beams. Is that what is used in space division multiple access? We maybe able also to have intelligent algorithm that senses the RSSI levels, provide feedback to apply combinations of selecting antennas, adders and delay circuits and eventually automatically select the sending location. I wonder if such a thing already exists?

[@iain_explains]

Yes, that's right. It's exactly what happens in MU-MIMO. The process you've described happens in the matrix operations in the receiver (for receive beamforming) and the transmitter (for transmit precoding). See "What is Multi-User MIMO Communications (MU MIMO)?" kzbin.info/www/bejne/Zp_GeoqindioZ6M

[@CanadianPranks12]

Interesting facts

[@havinganap]

Excellent. The idea of starting with the recieve case is genius!

[@iain_explains]

Thanks. Glad you liked it!

[@jayakrishnankr857]

Curiosity can put u anywhere and some places cant be forgotten .This place too💙

[@antonabik550]

Best beamforming explanation I have seen.

[@iain_explains]

Thanks for your comment. I'm glad you liked it.

[@dhananjaytiwari3213]

Thank you Iain, For making such a wonderful videos and providing us a valuable knowledge. Can you make a videos on DSP Filters (IIR and FIR Filters)? It will be very helpful.

[@iain_explains]

Thanks for the suggestion. They're on my "to do" list.

[@albertpicher832]

You even make it clear to me. Thanks a lot for ur work.

[@iain_explains]

Glad to hear that

[@MehnazRahman-v8x]

One of the best explanations. Thanks.

[@iain_explains]

Glad you think so!

[@ChayD13]

I never liked a KZbin video as much as i like this one. Indeed, it's the best explanation I have ever heard. Thank you so much for your work Prof. I wish I could have a professor like you in my university.

[@iain_explains]

Thanks so much for your very nice comment. I'm so glad you liked the video.

[@pk638684]

Thanks Mr. Iain for explaining in such an easy way the Beamforming.

[@iain_explains]

Glad it was helpful!

[@bennash4848]

So when the signal is cancelled out on the incoming transmission.. what happens to it...? Just got a bit confused at this point? How is a beam formed if it's cancelled out? Or... Have I misinterpreted what you have said?

[@iain_explains]

Yes, you're right, "cancellation" does take a bit of thinking about. One example in real life is at surf beaches, when a wave is coming in to the shore, and another previous wave is going back down the sand causing a ripple in the reverse direction. When the two waves meet, the peaks of the incoming wave add to the peaks of the returning wave creating a splash. But also, the peaks of the incoming wave are "cancelled" by the troughs of the returning wave, causing the water to be smooth a those points.

[@nusch_pl]

Thanks for explaination, now I'm wondering how the transceiver actually tunes to specific wireless client by selecting right delays?. Is it still in PHY or MAC layer ? Also how fast is the switching ? As if we have 4x4 router and two typical 2x2 clients how router assures signal from 3rd device will be still handled without comprising value added of two existing MU-MIMO clients?

[@hausdesigner]

Glad that I’ve found this channel and yeah best explanation I’ve ever heard

[@iain_explains]

Welcome aboard! I'm glad you liked the explanation.

[@MGTOW-nn9ls]

Dear Sir your videos are brilliant. Your explanations very clear .Thank you for sharing your knowledge

[@iain_explains]

Thanks for your nice comment. I'm glad the videos are helping.

[@SeanAM2023]

It's just awesome! Didn't know there is a similar beamforming effect in the receiving end as there is in the transmitting side.

[@iain_explains]

Glad I could help!

[@dimitrisv.1729]

A video with basic beamforming techniques for MIMO(or massive MIMO) systems would be helpful.

[@iain_explains]

Here's a link to my new video on MIMO: kzbin.info/www/bejne/inSUapqDhpuUsKc

[@johneicher6683]

Best explanation in existence.

[@iain_explains]

Thanks. I'm really glad you liked it.

[@xs1l3n7x]

I came here for fun, who else

[@tetianao2053]

Wow. That is the best explanation I’ve ever heard. Thank you so much.

[@iain_explains]

That's great to hear. Glad it was helpful!

[@wangjohn6639]

excellant!such a clear lecture to talk about beamforming. Thx very much

[@iain_explains]

Glad it was helpful!

[@林易-w3j]

Thank you! Professor! You are really good at teaching and educating!

[@iain_explains]

You are very welcome. I'm glad you are finding the videos helpful.

[@hosseinnouruzi730]

frankly it is the best explanation

[@iain_explains]

Thanks. I'm glad you liked it.

[@ibrahimbaras7648]

awesome explanation, I thought at the begneinggg how hw said best explanation , but he worth the name love the material Mr.Iain

[@iain_explains]

Glad you liked it!

[@deepinmoutain]

Thank you very much for the explanation. I have a question. Antennas are fixed on a wireless device. So, the distance between antennas will be the same. How does it work for different frequencies?

[@iain_explains]

Excellent question! The form of beamforming that maximises SNR (that I describe in this video) is inherently narrow band. In practice it doesn't have to be exactly half a wavelength separation, and there are approaches to designing beams that are wide band, but they come with a performance penalty in terms of SNR.

[@ankitbhanu5551]

Such a simple yet clear explanation, which even hour long fancy videos are unable to provide

[@iain_explains]

Glad you liked it

[@TheArtofEngineering]

I just saw your other video! Will watch that now!

[@iain_explains]

Great. I hope it helps.

[@hongliu909]

The best explanation I've seen 👏

[@iain_explains]

Thanks. I'm glad you liked it.

[@ankitaghorui900]

Hi Iain. Thank you for explaining this concept in such a beautiful manner. This video has proved very helpful for me in my first job.

[@iain_explains]

I'm so glad it was helpful!

[@bigdissocute8088]

u explained way better than my professor, thank you sir🥰.

[@iain_explains]

Happy to help

[@철민첩]

Hi, I am a student with master's degree studying communication in south korea. Thank you very much for the good lecture. You are the hope of the wireless communication. I have two questions. 1. If i want to implement a kind of antenna diversity through the two antennas on the receiving side, It is understood that when the awgn noise added to the signal from the two antennas is different, a gain of 3 dB is obtained. As you explained in the video, when i understand physically, don't the signals entered by the two antennas have the same awgn noise? That's the question I had in mind. Since there is a benefit from beamforming, I think it would be right to have different awgn noise, but I don't understand this clearly. 2. According to what i saw in the MIMO channel-related textbook, if the angle spread (dispersion of PAS) is narrow, that is, if the reception beam is narrow, the correlation with adjacent antennas increases. It states that channel capacity and divercity gains are reduced. Performing beamforming on the transmitting side will cause the beam to be browned, which is expected to result in relatively large correlation between the receiving side adjacent antennas. Then, is it okay to understand that it is a technology that has advantages in terms of energy concentration during tx beamforming, but also has disadvantages because of the high correlation? Thank you.

[@kongkong3678]

I am the author of this comment. dispersion of PAS (X) variance of PAS (O)

[@iain_explains]

It all depends on the characteristics of the channel. And I'm not sure you're understanding about the noise. Noise is introduced primarily by amplifiers in the RF "front-ends" of the transmitter and receiver. If each antenna is connected to its own amplifier, then the noise will be different for each antenna's signal. This video might help: "What are Spatial Diversity and Spatial Multiplexing in MIMO?" kzbin.info/www/bejne/g3-kYaukbKqYr7s and "

[@matlepak9694]

Excellent info. I wanted to understand beamforming microphone this explains a lot!

[@iain_explains]

Glad it was helpful!

[@elblanco5]

Woah, that was incredibly well explained!

[@iain_explains]

Thanks. Glad you found it useful.

[@fifaham]

This Beamforming, given fixed delay, is good only for fixed (position) signal source and fixed receiver - not for moving source or moving receiver, otherwise it will be hard to tune the delay in a way to match the movement of the source, or receiver. Has this technology "Beamforming" been used for moving source, or receiver, at all in practical application?

[@iain_explains]

Yes, that's right. When a source/target moves you need to adapt the delays. Then it gets called "Adaptive Beamforming".

[@marcinrybakowski8926]

Great explanations. Is it possible to visualize near field beamforming (beam focusing) in similar way?

[@iain_explains]

Yes, but in that case the delays are not constant between different antenna elements.

[@carmelpule8493]

What is never mentioned in antenna radiation is whether or not the E/M loops being radiated do break down into loops of half wavelength as the loop try to grow in size with distance, In waveguides and cavity resonators it is common to show the stacking of " half wavelength E/M blocks to fit in the available space. A one megacycle wave, has a much larger loop than a 5 GigaHertz signal and though everyone talks about lobes, and directivity, and efficiency, and so on, no one talks about the "stacking of E/M blocks" the size of which depends on the frequency of transmission. So for a given frequency , how many stacked E/M loops exist in it as the wave moves out? I have thought about this for the last 80 years and it seems to me that when one has a directional antenna, or a phased array, all that is happening the system is cutting off and eliminating the peripheral blocks in the stack of E/M blocks in the lobe or in any omnidirectional antenna, I simulated this with a computer algorithm which, when the circumference ( wavefront) of the wave grew larger than a wavelength integers, then the " circumference would accommodate another loop half a wavelength long". The simulation works beautifully and the patterns that emerge make it so obvious, after I saw it, From a central location of the antenna, after the wave settles down, the patterns seems to change from a "polar diagram" to a cartesian diagram where the four symmetrical squares of cartesian coordinates, simultaneously move out their four quarters containing the same pattern of E/M loops as exist in rectangular waveguides contain the higher modes. When I plotted the B and the E field loops far from the antenna they came out to be exactly as occurs in rectangular waveguides with the B loops as normal, and the E loops are exactly the same as the E in the waveguide and the surface currents in a waveguide, It is exactly the same pattern, So it seems, that a centrally placed antenna as a source, will have the near E/M fields going through "a pushy transient pattern" then "a middle field pattern" which I call the settling down zone, and then the far field would resemble the pattern obtained in a rectangular waveguide excited with an electric probe or a magnetic probe as one desires. It is fascination to see the four quarters of cartesian coordinates moving out with additional loops being added as the distance increases, It is remarkable, This stacking of E/M blocks, the size of half a wavelength, in a radiating pattern, is interesting, and in a phased array or a directional antenna, it seems that all one does is to " phase out the peripheral E/M blocks and donate the power to the other half wavelength E/M blocks remaining in the " stacked lobe" There seems to be more going on in radiation than one thinks, and this "stacking effect" needs further discussion . An analogy may be used by looking at Chladni's figures in vibrating sheets or a Jelly block, and after all our radiating medium is not much different from a jelly or a rubber block with its "own impedance" in how it permits our signals to "accelerate " build and decay and reverse those the E/M loops the size of half a wavelength. kzbin.info/www/bejne/raetcpqoiqd5atk

[@iain_explains]

Did you say you’ve been thinking about this for 80 years?! That’s impressive. What antenna systems were you working on 80 years ago? And since then?

[@hello-lb3vf]

phenomenal explanation

[@iain_explains]

Thanks. I'm glad you liked it.

[@oggamer2244]

sir you're so unbelievably amazing ❤❤. truly thank you

[@iain_explains]

So nice of you

[@Ulrich.Bierwisch]

I know beam forming from acoustic cameras that are using an microphone array to create a picture where you can see the source of noise. This allows to analyze what part of a machine, car, plane and such is emitting what noise. Might be a topic for another video.

[@iain_explains]

Thanks for the suggestion. I'll add it to my "to do" list.

[@muhannadaydi2235]

Thank you Pr. for this helpful video. Could you explain Beamspace in MIMO. Best regards

[@iain_explains]

Thanks for the suggestion. I'll put it on my "to do" list.

[@CrazyDBS]

hello, I'm from Brazil and I wanted to know if beamforming also improves latency/ping in online games, thanks

[@franzMTB]

Beam forming technique is only used into half duplex system?

[@robertharvey6725]

Great explanation. I expect that by changing the delay one could cause the beam to sweep.

[@iain_explains]

Yes, that's what's called Adaptive Beamforming.

[@AhtihsirFiles]

Firstly I would like to start off by saying thank you for sharing your knowledge with your videos which really are helpful to students like me. I watched your beamforming videos (in MIMO), I have a couple of doubts sir. Generally received signal from base station (having single antenna) to communication user(having single antenna) is written as: r = h*(root (P)) * x + n , where h is channel, root P is included to say that transmitted s/g power from base station is P (given E[|x|^2]=1) , x is a transmitted signal, and n is noise. Now, can the above equation be modified for a base station with M antennas as: r = h*W*(root (P)) * x + n , where W is beamforming weights. Is this correct? If so, what does this physically mean? Does that mean total power available at the base station is being divided among all antennas or in general how this transmitted power P is being related to weights in the beamforming vector. I'm confused sir, it would be really helpful if you clarify this.

[@iain_explains]

It depends on the norm of W. Generally we would use a W with norm = 1. Then, yes, it represents the total transmit power being allocated across the antennas.

[@AhtihsirFiles]

@@iain_explains Thanks alot for ur reply sir.

[@saranyakrishnan2386]

Thanku sir...understood perfectly

[@iain_explains]

Great. I'm glad it helped.

[@sagarraop]

This is really good one 👍

[@iain_explains]

I'm glad you like it

[@eightysevenmoore]

So… I created a machine monitoring daq using LabVIEW, mics and NI cRIO’s… about 4 months into monitoring a dyno i intuitively came up with this concept not knowing I stumbled upon beam forming by looking at hundreds of high speed wave form data… Thank you sir for plainly consolidating my mad-ness!

[@iain_explains]

I'm so glad my video helped you.

[@AA-gl1dr]

Fantastic lecture. Thank you.

[@iain_explains]

I'm glad you liked it.

[@hwan2909]

I can understand the basic princple of beamforming form your video, but I have a question. Consider 24Ghz freq MIMO radar system, which has the spatial distace between Rx antenna is lambda/2. To acheive +50 degree digital beamforming, the delay time should be (lambda/2)*sin(50degree)/c = 1.6e-11 sec. So, if I want to make 50 degree beamforming, the minimum sampling rate of MIMO system should be 1.6e11 Hz, which is too high to make a real system. I want to know how can I solve this problem.. Thanks.

[@FinalDestinationAllah]

Please upload more video on analog and digital communication, radios,SatCom,latest technologies

[@iain_explains]

Thanks for the topic suggestions. I've got them on my "to do" list (but it's getting to be a long list ...)

[@standardcoder1184]

6:40 Shouldn't that be 3 time the delay (and not twice) if we want the signal from non-equatorial source?

[@fnegnilr]

Great explanation! You just picked up another subscriber....

[@iain_explains]

Welcome aboard!

[@AetherXIV]

great explanation. Now my question is... will this increase a person's exposure to harmful EMF?

[@zahrazarei6858]

Thank you so much for the precise and clear explanation on this topic. I would appreciate it if you explain about coodbook based precoder and combiner in mmwave, too. I have faced some troubles understanding this topic.

[@iain_explains]

Thanks for the suggestion. I've added it to my "to do" list.

[@lephong8947]

Perfect explanation. Thank you Sir!

[@iain_explains]

Glad it was helpful!

[@markcraddock803]

Thanks a ton Ian. Not what I thought beamforming was. Excellent explanation of the theory of beamforming. Do you offer any in house training?

[@iain_explains]

I'm glad you liked the video. I'm not offering in-house training or tutoring at the moment, but potentially will in future. For now, the videos will have to do. Please do let me know if there are particular topics that you'd like to hear more about if I haven't covered it so far. Check out my web page which shows a fully categorised list of the videos: iaincollings.com

[@vikramgaud6276]

Thank you sir, for all of your videos; those are amazing😍. I have one doubt if we consider BS and UE then beamforming is used at BS only or at the UE side or both?

[@iain_explains]

It can be used by any communication device that has multiple antennas. So yes, it can be used at both the Base Station and the User Equipment, if they have multiple antennas.

[@vikramgaud6276]

@@iain_explains Thank you 😊

[@youssefguirat6419]

Best explanation ! Thank you !

[@iain_explains]

Glad it was helpful!

[@turan8737]

Thanks for perfect explanation sir

[@iain_explains]

Glad you liked it.

[@mehmetfatihayten8269]

great video, thank you!

[@hamedforouzandeh7274]

It's a little bit confusing for me as I thought most of the beamforming is done on the transmitter end while your explanation is mostly from receiver point of view. Would you please elaborate on this?

[@iain_explains]

Beamforming can (and is) done at either (or both) the transmitter and/or the receiver.

[@baghdadiabdellatif1581]

Thank you. The best explanation

[@iain_explains]

Glad it was helpful!

[@robertocabiecesdiaz3775]

I am trying to understand the MUSIC algorithm. Any link to easily understand it?

[@parisqasemian307]

You are very gooooood🌷🌷

[@idan1242]

amazing explanation very clear! but if im using only one channel/device does it better to turn off beamforming for smoother connection? thank you!

[@iain_explains]

I'm not sure what you're asking, sorry. Beamforming is a technique for increasing the radiated/received power in a particular direction. In its most basic version, it is tuned for a specific channel/user. In more advanced implementations, it can be tuned for multiple channels/users.

[@AK-xv9st]

Very clear explanation sir. What if I want to make a plot like that? Do you have an idea to make a beam pattern plot using Matlab or Python? thanks

[@iain_explains]

You might like to watch this video: "How does Antenna Spacing affect Beamforming?" kzbin.info/www/bejne/l57IoaycbpJ4Z9k and you'll be able to find the Matlab code I wrote for it on my webpage: iaincollings.com under the "Multiple Antenna Communications" heading on the "Digital Communications" page.

[@cchurchus]

Great explanation, Iain

[@iain_explains]

Glad you liked it

[@CHIUCHINGLIANG]

Thank you for the introduction

[@iain_explains]

You're welcome

[@TheArtofEngineering]

Fantastic explanation. I want to use 2 inverted L antennas to create a phased array. My existing vertical L is a 20m (14Mhz) with a little loading coil to resonate on 40m (7Mhz). How do I reconcile the distance between the antennas to the delay "harness" design required....Is 1/4 wavelength optimal.....could I compromise somehow to get it to work on both bands? I guess I would need a different delay for each of the bands?? Or is it a daft idea! :) 73 de VK2AOE

[@iain_explains]

You'll definitely need to match the delay to the centre frequency of the band .. seperate delays for seperate bands. There are wide-band beamforming techniques, but it's always a trade-off. Beamforming works best when it's narrowband.

[@TheArtofEngineering]

@@iain_explains Thanks....I loved your explanation it made the concept clear. As with all Engineering the devil resides in the detail. Thanks for the answer.

[@iain_explains]

I'm glad I've been able to help.

[@emanuelepulcidoria2857]

Thanks Iain, this is a very good explanation. It is based on the simple case of a single known frequency incoming wave. What happens if you do not know the frequencies of the waves you are picking up, or is this something you must know beforehand?

[@iain_explains]

If you don't know the frequency or the direction, then you need to do some sort of beam scanning, and search for the signal. There's a lot of research on this topic. Maybe I should think about making a video on it.

[@emanuelepulcidoria2857]

@@iain_explains Thanks Iain, I was researching the beamforming topic to better understand the towed array bearing ambiguity for submarines and indirectly your video explains this ambiguity quite well. But how you process and determine the direction of more complex signals composed of all different frequencies it is still not really clear for me.

[@支言骗语]

Very helpful video sir ! And could you explain the difference between beamforming and mimo precoding? It seems that precoding is cand like more optimal version of beamforming.

[@支言骗语]

I see in some books what they call transmitter beamforming is basically precoding. I am very confused since most people when talking about beamforming talk about carrier phase, and when talking about precoding talk about data symbols.

[@支言骗语]

Are they equavlent? Is precoding basically another way to adjust carrier phase and amplitude through adjust data symbol ? And could you explain what kind of beamforming is actually deployed in systems such as LTE and 802.11ac, are they just steering carrier phase at each tx antenna. Or are they trying to find the "optimal" precoding matrix to maximize rx SNR? If the latter is true, do the reciver need to do some post process to understand the precoded signal ?I found a lot of information conflicts with each other about this topic.

[@支言骗语]

Sorry for my poor english expression. And thank you very much.

[@iain_explains]

Thanks for the question. I've added it to my "to do" list for an upcoming video. In summary, traditional beamforming (BF) refers to the phase adjustments between antenna elements in order to "direct" the energy, so as to maximise the SNR in the direction of interest. "Digital BF" includes amplitude and phase differences between the antenna elements (again, to maximise the SNR). "Precoding" is a more general term, that includes BF, but also includes other cost functions (not just maximising SNR). Many precoding techniques require the transmitter to know the channel gains.

[@flyingpinguu]

Thanks this made me understand it better! It still left me with a question though. If you look at an angle such that the phase shifting is exactly a whole period, the waves will still add up constructively there. How is it made that these side maxima are so weak in phased array antennas?

[@iain_explains]

Yes, that's a good observation. This effect depends on how far apart the antennas are spaced. Check out this video for more details: "How does Antenna Spacing affect Beamforming?" kzbin.info/www/bejne/l57IoaycbpJ4Z9k

[@ayushidube4032]

Very illustrative and logical thank you 😊

[@iain_explains]

Glad it was helpful!

[@tariqislam9388]

Very useful. Very well explained.

[@iain_explains]

Glad it was helpful!

[@hassannoghrey2157]

thank you so much for your video. I have a question? for a mathematic student, which books or courses do you propose to learn these concepts deeply? best.

[@iain_explains]

Here's a good book: D. Tse and P. Viswanath, “Fundamentals of Wireless Communication”

[@hassannoghrey2157]

@@iain_explains Thank you so much

[@wunxue]

How far is far enough for considering the wave front to be flat?

[@FreemanEvents]

Thanks mate for the explanation. Makes sense.

[@iain_explains]

Glad it helped

[@betanapallisandeepra]

Good explanation… 😊 thank you

[@iain_explains]

Glad it was helpful!

[@emielregiss]

Well, the speed of light is ~ 3x10^8 m/s. So if our antennas are for example 30 cm apart from each other, then if my calculations are correct the time delay would be around 1 ns (nano second). Can it make such a difference? Are our electronic devices so sensitive and accurate to detect even this? For comparison let me add that for example for LTE the symbol duration is around 71 us (micro second) which made me wondering whether a few nano seconds can make a difference here.

[@iain_explains]

Well, it's no different to how your brain uses your eyes to work out how far away something is. And your eyes are even less than 30 cm apart!

[@emielregiss]

@@iain_explains Good catch:) So you are saying that our mobile phones are so advanced to detect this? That is very interesting. I am no expert in electronics, just curious how it works.