type of modulation

[Q8RoSe]

Hello I need some helps in some type of modulation like :
Amplitude shift keying (ASK)
Frequency Shift Keying (FSK)
Phase Shift Keying (PSK)
Differential Phase Shift Keying (DPSK)
I need to know the Tx & Rx

regards,
Q8RoSe

 

[audioguru]

Please ask your teacher, look in a text book or look in Google.

 

[silvarblade]

Hello I need some helps in some type of modulation like :
Amplitude shift keying (ASK)
Frequency Shift Keying (FSK)
Phase Shift Keying (PSK)
Differential Phase Shift Keying (DPSK)
I need to know the Tx & Rx

regards,
Q8RoSe

i didn't get your question correctly? you want them explained?or knowledge about receiver and transmitter?

there are a lot books around for e.g for explanation Communication Systems by Simon Haykin although you wont find the RX and Tx diagrams there but it is the best book that i have come across up till now.

 

[Q8RoSe]

Yea i wants knowledge about receiver and transmitter about these modulation and i prefer it in a short passage and there is no problem if they were explaind i would be thanksfull .. i know but i need some help ,.. heheheh no plz idont want my brain exploed its already exploeded heheheh ..
thanks for your help

 

[RadioRon]

Modulation means to change a carrier in some way from one instant to another so as to convey information.

ASK means Amplitude Shift Keying. This means that the amplitude of a carrier is being shifted up and down following a serial bit stream. This can be received using a receiver with an AM detector. It can be transmitted using a transmitter with an Amplitude Modulator. The most common type of transmitter for this kind of modulation is the typical garage door opener, in which an internal oscillator is turned on and off to create the amplitude modulation. In this case the amount of modulation is 100% (On is 100%, Off is 0%).

Frequency shift keying means that the frequency of a carrier is shifted back and forth between two different frequencies following a serial bit stream. Usually the transmitter uses a Frequency Modulator which is fed by the serial bit stream. A frequency modulator is often just an oscillator with a varactor diode placed in the resonant circuit so as to allow a change of capacitance, and hence a change of frequency, when the input voltage changes from 0 to 1 or from 1 to 0. For receiving this kind of signal, an FM receiver is needed.

Phases shift keying means that the phase of a carrier is shifted following a serial bit stream. There are many kinds of phase shift keying and the main difference between them is the amount of phase that is changed. The simplest is binary phase shift keying, in which the phase is changed 180 degrees when the incoming bit stream changes from 1 to 0 or 0 to 1. The BPSK modulator in the transmitter is often just a mixer. Google BPSK for more details. The receiver might use an FM detector, or it might us a PLL type detector to receive such a signal. Many modern devices use phase shift keying, including cell phones. They usually demodulate the signal by mixing to In-phase and Quadrature (I&Q) baseband and then passing these into a DSP to demodulate numerically.

Differential Phase shift keying is a type of phase shift keying. The method of receiving is most commonly done in DSP as mentioned above. See this link for more details:
**broken link removed**

For more details on all of these subjects, find a library and read books about them.

 

[Q8RoSe]

Thank you very much ... but could you please give me few suggestions on what sort of websites should i look in to , to help me get more details about the modulation because as you know i need to write two pages on each type ,,, and thank you

 

[Space Varmint]

2 pages for each one? That's allot! Why don't you just google it? If you can get a hold of an ARRL Handbook you could find everything you need.

Can you fill up any pages with schematics? That might be the way to go. Do a schematic on each one with a write up.

 

[silvarblade]

type 'digital modulation' in google and you will get a lot of hits.some of them are good.

 

[Mikebits]

Thank you very much ... but could you please give me few suggestions on what sort of websites should i look in to , to help me get more details about the modulation because as you know i need to write two pages on each type ,,, and thank you

And to think I was mad about having to write a 5 page paper about euglenophyta over the holiday break. 12 page paper, better you than me...

 

[RadioRon]

And to think I was mad about having to write a 5 page paper about euglenophyta over the holiday break. 12 page paper, better you than me...

Your paper could be a minefield of terminology misunderstandings. I note the method of nutrition is phagocytosis, and that these flagellates which are distinguished by their long pellicle, were first defined by Mr Butschli. Be careful with this one. Some academic institutions (see link) are starting to use thought police and pc wardens so its only a matter of time before this whole field of study is shut down due to incompatibility with pc principles.

**broken link removed**

 

[Q8RoSe]

thanks all for your help ...

 

[Space Varmint]

thanks all for your help ...

Your welcome. Did you figure it all out? Good. Now you can tell me how to do it all.

I got screwed up building an SSB trnasmitter. These yahoos on here attacked the crap out me about matched diodes in a balanced modulator which bugged the hell out me. I've built SSB before but it's been a while. There are tricks to keep the diodes from cracking on ya but the topic is interesting and I think I will redo the balanced modulator when I get a chance. I really like this article about it: **broken link removed**

But I have another bigger problem. I'm trying to mix the transmit frequency up higher and the output of my filter wants to produce a small carrier even when there is no output or supposed to be no output. Part is coming from the local oscillator, maybe I got some leakage though my home made crystal filter. Not sure and have to wait to get back to it. One thing you don't want to do is have a small carrier leaking out over the ham bands or you will never hear the end of it. Allot these guys think nothing of dropping 50 grand on thier transmit equipment and they will even complain if your running atleast a half a KW. They will tell you to, "put some fire in that wire!".

But it's a fun hobby...ham radio. You might wanna try it if you get to where you want to get some hands on.

 

[Q8RoSe]

https://www.electro-tech-online.com/custompdfs/2008/12/13_fsk_2up.pdf
I got this link it will help you

 

[Q8RoSe]

hey ..
which is the best modulation ASK or FSK or PSk and why ?

 

[Nigel Goodwin]

But I have another bigger problem. I'm trying to mix the transmit frequency up higher and the output of my filter wants to produce a small carrier even when there is no output or supposed to be no output. Part is coming from the local oscillator, maybe I got some leakage though my home made crystal filter.

That's because your balanced mixer isn't balanced accurately - yet you claimed the carrier was 120dB down in your previous thread.