welcome to communication engineering ladies here in this session are we going to explain you basics regarding the SBS C double sideband supprised carrier so this session is all about what is the SBS see why there is a need of DSBs see how DSP AC signal can be generated what is that DSP AC signal and how it is important to solve problems based on BS BSC so all those things that I will be discussing in this session now see before we go for double sideband single carrier I have already explained you amplitude modulated signal and that we have seen and we have derived its equation AM signal and that equation was this output of AM signal that is why D is equals to AC cos Omega CT plus mu AC by 2 also Omega C plus Omega MD plus mu AC by 2 cos of Omega C minus Omega M T where this is carrier this is carrier signal and this is upper sideband signal and this is lower sideband signal and we have seen some other forms even where we have seen like amplitude modulated signal is this and you can simplify this in this term but this is carrier signal and this is sidebands now see when we talk about information then information is not there with carrier signal so in M signal we send information plus carrier signal so information is there inside bands so upper sideband and lower segment that is having information while in carrier signal there is no information so usually we are wasting power in carrier signal when we send and they could modulated signal so ultimately in the AM signal it is having major drawback o carrier signal which is what we are sending over modulated signal so in the SPS C we will be suppressing this it means we don't send this so this is what the component which we eliminate and DSPs C and that is what AM signal without carrier so DSPs T is AM signal without carrier means double sideband suppressed carrier it is having two sidebands upper segment and lower sideband it is not having carrier signal which is what we are sending in AM signal so this is what we need to keep in our mind the SBAC means what the SBHC means double sideband suppress period where we don't send carrier signal we only send upper sideband and lower sideband now see we have already derived power transmission of a.m. so in power transmission of a.m. there are two components of power one is carrier power and one is sideband power carrier power is PC and sideband power that is nu square by 2 into PC when mu is modulating index so when we send the word segment carrier double sideband suppressed carrier in that case we did we don't send this signal which is carrier signal so only this component that we are able to send in DSPs C now C it is how it is creating at one day so for that I am just considering one example of modulating index that is equals to 1 so if modulating index is 1 then you will be finding transmitted power that is PC plus if you place one over here so 1 by 2 means 0.5 PC now see in yes see we don't send this in days BAC we don't send this on this component that we are sending so ultimately we are saving this much amount of power when we signed information so this is what the basic advantage which is rapid DSPs C in which we don't send the carrier signal we only send upper sideband and lower sideband and that is what solving issue of power transmission by very large amount the reason is major part of power you can see if you consider the total power of AM signal that is 1.5 C 1.5 PC form U is equal to 1 so information power is only 0.5 DC it means only 33 percentage power that is there with sidebands and 66 percentage power that is there with failure so if you send DSPs C you will be saving this much amount of power which is major part off and it with modulated signal so this is the basic advantage now question is what is the basic case which is there with DSBs C so I will explain you that by a basic block diagram where here one can see we have two signals what is modulating signal which is low frequency signal and second is carrier signal that is high frequency signal now by using product modulator we can multiply this two signal and we can generate DSPs C output signal like C we have HP that is modulating signal and we have seen D that is carrier signal so output of product modulator that is yd that is equals to X plane into CD well CT is carrier signal you see cos Omega Sadie so our D SBAC output that is a CHP cos Omega C D so this is what the basic out output which is with the SBAC and that is how we can generate the SBAC signal in future I will explain you different methods of generation of DSP SC but in layman's language we can understand like this is what DSPs signal now question is how DSPs signal will look like so for that I'm considering one example where here you have this modulating signal now to generate DSPs a signal we just need to consider and well above this so similar negative angle of that I am plotting here so this is modulating signal by red color I am just creating one envelope which is of exactly same out magnitude in opposite direction so this is what amazing now when we send signal by multiplying carrier signal then what happens is this carrier signal that is getting multiplied with this so it will be creating this kind of output now what will happen here when 0 crossing of this modulating signal is happening at that time output will be having 180 degree phase reversal reversal so here output is having 180 degree phase reversal so here signal is going like this so it should go in this direction if there is no phase reversal but here because of phase reversal signal will having phase reversal like this and this will be the output so ultimately here few points that we need to understand first phase in DSPs see we don't send carrier signal in DSPs see we don't send carrier signal second point is only lower side men and upper sideband signal is then it's only lower segment and upper segment signal that is there in DSBs see and third point that is it has 180 degree phase reversal and zero kasi Oh modulating signal like C as I have told this is modulating signal so here modulating signal that is all that you first so when modulating signal is positive right so I did an output is positively multiplied with CD but when modulating signal that is negative like phase viewer when zero crossing is happening modulating signal will be negative so at the time output negative x CD so that will be 180 degree phase reversal now when you see its frequency response of DSP a signal so in frequency response of the SBHC signal here that is frequency and here that is amplitude so in that you will be finding that is two sidebands lower segment and upper side way lower segment that is I think 1 C Omega C minus Omega M and upper segment that is having frequency Omega C plus Omega M and you will be finding Omega C that is carrier signal that is having 0 magnitude so only lower sideband and of assignment that is what we are forwarding and output side in DSBs see and here if you see what is the bandwidth then bandwidth of this that will be this much and if you see the difference between these two frequency Omega C plus Omega M minus Omega C minus Omega M so that will be 2 Omega M so bandwidth of DSBs C that is similar to the bandwidth of AM signal so there is no change in bandwidth but we provide reduction in power transmission in the SBAC that we can see over here so in DSPs C we save power in terms of transmission power in if we sieep and it will be 2 Omega M well we don't send carrier signal so here even you can see in AM signal we have removed this carrier signal we only send upper sideband and lower sideband so we see you at 3 moment of power in terms of transmission by you having d sv SC in amplitude modulation and basic generation of vs d HD signal that will be by product modulator where by just multiplying modulating signal with carrier signal we have the SBHC signal and that is what we can generate it like this I give modulating signal is like this make that and carrier signal that is what we are sending it over modulating signal and when 0 coursing is happening at a time carrier signals phase reversal will be there so here this signal by blue color one can see this is d SB SC signal well that will be phrase reversal at zero crossing of modulating signal so these are the basics which we need to understand when we send DSBs signal or channel in nitration I will explain different types of modulation for generation of d SB SC Sun cover total for different methods by which we can generate d SB SC and that will helpful to you to understand how we can generate BSBA signal thank you so much for watching this video you can give me your valuable suggestions your solutions are most welcome to me it concludes what is that which is required over here so probably you should send me your valuable suggestions definitely I will take care of all those suggestions and based on my understanding I will try to sort out all those queries thank you so much for watching this video