Recent content by Asma

Thanks for your answer... It is clear now.. Thanks

But x[n+1] means that the sample is shifted to the left, (less than 0 or means it is positioned at -1) so it is a past value then the system is causal.!

I really confused, I found in a book that the following system, y[n]= x[n+1]-x[n], is not causal! But from the definition of causality that the output y[n0] depends only on the input samples x[n] for n<=n0,,, So I think that this system is causal... If you agree with me please tell me that...

Thanks all,,, just I would like to mention the main difference between them. For the radio station, because all receivers receive the same information, hence it is limited by propagation. But in cellular system, each user wants different information, so it is limited by bandwidth. So the...

Thanks all for your response.. I am doing MSc of information and communication engineering...

Thanks for your answer... :)

Please help me with this... Why a radio station can be broadcast to a whole city from a single antenna, whereas a mobile phone system needs a network of basestations? Thanks,,,

Thanks berkeman.. The band width need to use it was 10kHz, the modem will operate on 2GHz frequency,,and the onboard instrument produces data about 200 bps (fixed),, and each modem will have SNR 50db for 20%of time and 20db for 50% of time,,,these are all my given parameters..

Digital modem design Hello.. I need a help with my design study, I am asked to design modem for UHF, 2 GHz, for rescue helicopter with speed 200km/h, to send 3 types of data, speech, image and onboard instrument data,,, I nearly finish my design,,, but I stuck in point,, as a part from my...

Thanks for your response..

Hi all... I am trying to design digital modem to send 3 things,, audio, data and image, the problem that when I try to send image 640x480 pixel, with JPEJ format, I need to get a value for a transmission time by using the type of modulation scheme and symbol rate, my question is what the...