Recent content by Fisher92

Thanks, I came to the same conclusion.

Homework Statement The problem was actually for a COMMS assignment that I have finished with the exception of the very last easiest part. They wanted percentage of power spilled into gaurd bands - have calculated all the powers now need the percentage... I have two frequency components...

I thought that was interesting too. I don't know if there is any reason for me to use double modulation for this question as it is not really a design question? Whould you amplify the information signal as the textbook does? No information on the nature of the signal makes it hard but there...

Missed something very obvious in my COMMS textbook when we started to design the actual filter... Attached because I thought you might find it interesting - there is also a textbook example of SSB-SC with a filter to eliminate a sideband... Swear I went through this when I first started the...

Hey RM, my lecturer got back to me on this- 1. You do not need to actually design the filter. 2. If you wanted to design a filter with this high a rolloff you would need crystal or ceramic filters. 3. Just work out Q & fc and use them as blocks in the system diagram. 4. Low pass filter is...

To me a mixer is not necessarily DSB-SC - Could be DSB-FC or anything, generic term for a modulator - I was thinking that I wanted DSB-FC for this part of the question - From your answer it is clear that is not the case though. One LO @ 6kHz to be used as a '1st stage' carrier will give all...

How would I determine the heterodyning frequency such that the requirements on the filters are them same. Firstly I need to determine the lower order carrier (this is another oscillator, so I would end up with 8 LO, 4 analog mixers & 4 ring modulators in my design to get the 4 SSB-SC signals?)...

Hmmmmmm... I definitely see your point here. - Good explanation. I have an inkling that this is beyond the scope of the question - although definitely interesting so I will no doubt look into it regardless. - I will consult my lecturer about what it is he wants... The question explicitly...

Yes, all the literature agrees - only reason I can see to force us to this methodology is that the other methods are conceptually more difficult. I suspect this is a question to prove that we understand what SSB-SC is. &FDM Low Pass Filter on all four channels starting at the carrier...

-The question was effectively explain the operation of the superhet but in parts.. One part was the BP filter BW necessary to eliminate the image problem. We ended up having 2fIF... Lecturers response to this was 'filter is centered around fc so it should be twice this...4fIF' Mistake cost me a...

Thanks RM, haven't read any other posts - didn't even get an email for that one for some reason. Firstly, Yes that does sound reasonable. -I agree this is valid & gives better channel separation. In this case I will be keeping the LSB and discarding all the USB with my filters? Since FDM in...

Homework Statement Due to its bandwidth and power efficiency, SSBSC is commonly used in Frequency Division Multiplexing (FDM) systems. FDM systems are used to combine a number of separate information channels into a single transmission. Each channel uses a separate carrier frequency and the...

Righto, Thanks for your help...

RM, the table is the same as before minus the negative powers? This is the distribution plot for the question, sorry about the stupid water mark. I also did an xy scatter plot for the two distribution which look s a bit cleaner. ... My answer for part c is the same as I did the sum...

Power can't be negative can it! Re the sqrt(2), I omitted it on purpose because I stated a 1V rms carrier which would negate the need for the sqrt(2)-unless I am mistaking about why it is there? Yes, we definitely decided to treat them one at a time AND no it doesn't make any sense to assume...