DSSS - Direct Sequence Spread Spectrum

[@taguetrash]

Possibly the only good visualization and explanation of this concept on KZbin!

[@antoniopintus8568]

You are simply a master class teacher! smooth , calm and clear ! not a common thing really !

[@sunnyclassroom24]

Thanks! 😃

[@onnguyen3408]

Thank you Sunny, you are the best telecommunication professor I have ever seen.

[@thezombieguy426]

out of all videos I pick yours because the way you explain concepts is clean and simple to understand

[@sunnyclassroom24]

Thank you for watching! I appreciate.

[@overdrijft]

You're the best, Sunny! All of your videos are ever so helpful.

[@sunnyclassroom24]

Thanks.

[@getanehgeto7873]

A lecture who can be a role model for others, God bless you!

[@srb1855]

Sunny all of your videos are excellent! Thank you for all your effort and exquisite execution.

[@sunnyclassroom24]

Thanks a lot for your compliment and encouragement.

[@080_cse_sanjaykarthicks4]

Thank you for this awesome lecture This guided me to understand this concept and i'm feeling bit more confident to take seminar on this topic after watching this video

[@mohamedisaac924]

man you are even better then my teachers i learned a lot from you thanks ( you're the man )

[@Thinkchronous]

great explanation. I liked how your words were in sync with the animation!

[@sunnyclassroom24]

Thanks a lot for your comment.

[@علياءعلي-ص2ب]

No words can describe how much l'm grateful . Gog bless you ❤️

[@manafsliman3734]

You sir, for sure deserve more subscribers and viewers, thank you so much for your work.

[@drvisalakshipalanisamy6188]

Excellent video lectures . Every concept is covered in a simple and clear manner.Hats off.

[@sunnyclassroom24]

Thanks a lot for your nice comment.

[@NyambeLilonga-w1q]

You are my life saver. Keep it up with the good work.

[@kirklawrence4326]

excellent job at explaining. Clear and concise.

[@raviroogi9030]

Good sunny, I really appreciate your smart explanation

[@rogeliovegam]

Sunny you are a Genius. !!!. Thanks for this clear explanation

[@sunnyclassroom24]

you are welcome and thank you for your kind words, Rogelio.

[@maxwellchiu6859]

Hey Sunny: You didn't mention it but you are actually talking about Barker Codes. I have been looking into Barker Codes and Convolution and this video actually filled in a lot of gaps in my understanding of Barker Codes. I'm not really there yet with Barker Codes, but this video sure helped me get closer. Thanks very much.

[@hanjoradja569]

Good Job Sunny, your video is very helpful, explain with a gentle clearly sound.. make me easy to understand.. GREAT!

[@sunnyclassroom24]

Thank you very much, Hanjo!

[@sangeethmv1233]

Very effective teaching....

[@sunnyclassroom24]

Many many thanks

[@rushikeshwaghmares6476]

So easy to understand concepts , thanks

[@jakubadamczewski3477]

You saved my time, amazing video! Thanks!

[@herethere-o1r]

Thank you, sir! You are doing a great job.

[@劉時淼]

I say to myself that I do really enjoy watching your video.

[@sunnyclassroom24]

Thank you very much!

[@sudarshandevarasam]

you saved me, thank god for sunny

[@sunnyclassroom24]

God bless!

[@SuppaBoii]

Good Job man !!!!!

[@sunnyclassroom24]

Thanks!

[@Abiwrl]

Amazing! Thank you Sunny!

[@sunnyclassroom24]

You are welcome!

[@srinaath9845]

Thank you Sir.You help me out every semester.

[@PatelJitendrabORN2sUCCEED]

wow, Plain and simple.. thankyou

[@MegaJohnhammond]

One of the best benefits is you can transmit multiple channels on the same frequency using different codes for each channel. That's how GPS satellites work.

[@anggasukmabahari6342]

This video are the best! Thank you sir!

[@sunnyclassroom24]

You're very welcome! Thank you for watching!

[@mariodelzo]

One more great video. Thank you!!

[@sunnyclassroom24]

My pleasure!

[@cheelikumar]

best clear & concise explanation sunny....love from india

[@sunnyclassroom24]

Thank you very much! Thanks from Kansas, USA.

[@Infinity2zer0]

Really useful, thanks, that's amazing

[@edsonferreira4800]

Thanks for the all knowledge teacher

[@richenjoshi7054]

You explained it so well, thanks

[@shreyaovalekar6764]

Thank u so much! U made the topic easy to understand

[@TamaDebnath-v2e]

It was really helpful.Thanks a lot.

[@needsomehike]

at 05:40 Sunny says lower power = harder to detect and interfere. But lower power also means that the SNR will be lower so the signal will be more effected by noise=less reliable connection. Can someone please explain that how lower power is better to avoid interference?

[@makharsa12]

yes, this is the idea of the whole DSSS. you need to send at a much lower power because your signal is supposed to look like random noise with low power. But the cost you are paying however, is widening the frequency band (and this what we are doing by XOR your normal data rate to a much higher data rate at 3:25 , you are increasing the bandwidth more of that what you really need) and using all of your available bandwidth to send the one signal. DSSS utilizes the whole bandwidth to lower the SNR needed to be transmitted. when you are sending multiple signals, PNs should be different and all of the signals should have minimal power to avoid having one stronger signal than others. because you are basically using the same bandwidth for all of these signals. And if all your PNs are well crafted to be unrelated to other PN, you can reconstruct all of your signals at the receiving end

[@fahadalhussein5407]

at the receiver end when you do the mathematical operation of correlation with PRN of the RX ( as part of demodulation ), the desired signal will increase in magnitude, on the other hand correlating anything unwanted ( noise , interference etc ) that enters the receiver will result in a low output. for the sake of security, you want your signal to hide in the wireless channel like if it is noise . I might be wrong.

[@windogwow]

This is gold! I do have couple of questions: 1. What is narrowband and wideband? 2. If the bandwidth or the “spread” of a narrowband signal becomes “wider” as shown in the diagram, wouldn’t it cause interference with adjacent frequencies and also become “weaker” to travel far distance? Thank you!

[@keertivaassankaranarayanan3117]

Nice video to understand concepts!

[@stepannovotny4291]

I don't see how you could achieve a 10:1 frequency spread at the physical layer using DSSS, whereas with FHSS you can simply have two receivers where one is tuning while the other is receiving. Any comments? A video on the physical layer would be very valuable. Nice channel by the way!

[@mohammedjawadkalburgi2208]

no doubt ,ur greatest of all

[@raymondthalseth3920]

Fantastic! Thanks :) The use of more than one example is so helpful :)

[@qiucuojimei5852]

Thank you very mich for your great explanation.

[@mdsakilbhuiya8689]

Sunny, you are a great teacher.thanks a lot.

[@damaylaphoenix1155]

which is better ?

[@f4z0]

Excelent job, super clear explanation.

[@allthingsikki7659]

SOOO much helpful, Thank you!

[@testuser_tgo]

Tks so much my man!

[@augmentos]

Awesome as always Sonny. I wonder can FHSS them be blocked/jammed or interupted? Or is it otherwise the most resilient?

[@Nath-pk5nk]

Great video. Can you explain how increasing the spreading factor effects the bit error rate ?

[@linn8007]

you are brilliant

[@alalolol9949]

Thanks for this wonderful video. Could you further explain how DSSS makes Inter-Symbol Interference negligible in the multi-path scenario?

[@DeshantaDevkota]

Thank you sir.

[@johnaweiss]

6:08 Sunny, FHSS was developed in 1942 by a Jewish American refugee who became a Hollywood actress. She invented it to help the Allies defeat the Nazis, but the military REJECTED FHSS, and didn't use it until the 1960's. "Frequency-hopping spread spectrum (FHSS) radio technology was originally patented on August 11, 1942, by actress Hedy Kiesler Markey (Hedy Lamarr) and composer George Antheil. It was originally designed to be a radio guidance system for torpedoes, a purpose for which it was never used. The idea of spread spectrum was ahead of its time. During World War II, Lamarr learned that RF-controlled torpedoes of the United Sates Navy, could easily be jammed by the enemy and veered off-course. This made it more difficult to sink the enemy’s ships. So, Hedy Lamarr brilliantly came up with the idea of a frequency-hopping RF guidance system that would be very hard to jam. Together with George Antheil, they created a RF transmitter device that emulated player-piano capabilities… and frequency hopping was born. They filed a patent in 1942, however, the US government immediately classified the technology. FHSS was not used in time for World War II. It was not until 1957 that further development on spread spectrum occurred [at Sylvania Electronics], and in 1962 frequency-hopping (FHSS) was used for the first time between the US ships at the blockade of Cuba during the Cuban Missile Crisis." www.extremenetworks.com/extreme-networks-blog/happy-birthday-hedy-lamarr-wi-fi-visionary

[@maathoukbenziane1087]

tnks sunny

[@kiwiaburridoo]

I don't understand why it is likely to have low-power signals. Don't make them more difficult to diferentiate them from awgn noise? Sorry if I missed something actually obvious, I'm beginning to learn about data transmission. Oh, and great video Sunny!

[@Eng-Ziaullah]

sir which one is most suitable spread spectrum techniques in term of providing security in wireless networking

[@rasswanth4968]

Good one.

[@sunnyclassroom24]

thanks.

[@shanahmed9710]

Hats off!

[@hassan_mohd]

Thanks thala..

[@sunnyclassroom24]

You are welcome!

[@Sparkydizzle86]

So what is better dsss or fhss? And can unrelated this to dsmr as used by spektrum in rc applications?

[@ananthu4141]

Sir What we do in case of Barker 11 sequence provided with an original data of 3 bits

[@ganeshsahane5766]

thank

[@sunnyclassroom24]

you are welcome

[@udayposia8082]

Best explanation ever, Thank you :-)

[@sunnyclassroom24]

You are welcome!

[@brajmandloi6232]

Great explanation.

[@sunnyclassroom24]

@@brajmandloi6232 thanks

[@NA12495]

Do you have a more in-depth explanation as to why it is immune to noise?

[@CuongHut]

Thank you sir for your video. But as I was taught, when data is modulated with PN code, 1 and 1 is 1, not 0 as your instruction. Correct me if i am wrong. Thank you

[@sunnyclassroom24]

we use different table. Exclusive OR truth table and Truth table (which you mentioned) is different.

[@CuongHut]

@@sunnyclassroom24 I got it, thank you so much.

[@jung1020lee]

i have one question. I have seen a solution that converts and transmits a dsss signal in reverse phase. Is there a difference between normal dsss transmission and reverse phase transmission?

[@aaronacj]

hope this helps get me through CISSP...

[@Mr_ASIC]

how transmitter and receiver sync the PN code to demodulate data ?

[@uttamsharma6358]

Great explanation. I am curious that when is the PN sequence decided and by whom? I know about shift registers but is it decided before session starts or does it keep changing in the middle of session? Is it multi-casted by transmitter or something else?

[@tomatrix7525]

I think the Wireless adapter chooses it at the start of session by randomely choosing an n bit encoding. And there is practically no chance any other device in area will be on that exact same n bit encoding. The probability is negligable.

[@windogwow]

I am only assuming this PN code would be something similar as a “private” key in crypto world which is exchanged before passing data and can be constantly changed for security purpose.

[@mmkvhornet7522]

i believe that the PN sequence is agreed upon beforehand

[@archanarajr6580]

Thanku sir..

[@AnthonyGutierrez-t8y]

I wouldn't consider using more bandwidth an advantage of DSSS. Especially when we're trying to maximize efficiency of the spectrum. However, using more bandwidth is necessary for spreading.

[@kalamsha3044]

thank you

[@sunnyclassroom24]

You are welcome!

[@muhammadsharifhaider2038]

Sir, I think in the truth table 1 and 1 using OR Truth table results 1.

[@rheniuspaul389]

Hello there sir first of all this lecture is op and pease make full video if possible with mathematical analysis and the demodulation part thank you

[@lowspoke9974]

Set 1.25 speed before watching

[@shaunwong7870]

prefer setting 1.5 speed LMAO

[@davidwarner2491]

@@shaunwong7870 me too

[@ApsaraSawin]

Ha ha 😂

[@Felink21]

Always use OR table?

[@ojaspurohit5852]

Why is usage of more BW a benefit?

[@tomhardy6643]

Could U please put the all u wanna say as a text in description?

[@sunnyclassroom24]

will do.

[@WoWPro71]

Isn't it supposed to be XNOR and no XOR?

[@arsalalam5998]

nice.

[@DrN007]

I don't get how it's "spreading" frequency of the signal. Based on the explanation, it's only increasing the frequency required to transmit, while still keeping it narrowband.

[@DrN007]

Unless, it applies many different PNs & transmit them simultaneously?!

[@adityachopra3759]

Looks like a cooking class

[@piyushgarg2402]

bhaiyon aur behno is video ko like karo

[@anurag_singh123]

I always watch this in 2x speed.

[@mohammedjawadkalburgi2208]

keep posting please

[@ahmednor5806]

🙏🙏🌹🌹

[@dungngoviet1834]

OR truth table ?? this is XOR

[@sunnyclassroom24]

XOR is exclusive truth table, which is different from OR truth table.

[@harshitvishwakarma310]

Thats call digital learning ...i hate my education system just blackboard n chalk thing....it sucks

[@sunnyclassroom24]

Now many schools have digital presentation.

[@AlbertSebolino-r3e]

W

[@SazzadHossain-xl1pq]

নাসকসক

[@منتظرطيب-ك3ب]

ل ٦سادس قبل أسبوع ويوم الحسين عليه وسلم في