homodyne

from what I have read, homodyne transceiver uses Complex mixing while heterodyne receiver doesn't. Most system nowaday are using homodyne setup, is this correct? I'd thought most are using heterodyne. Anyway, so what exactly is complex mixing? Is it because we're multiplying with a single tone? .....could someone please help me clarify it, I don't think I fully understood it. Thanks

yeah these days most the integrated receivers use the ZIF or homodyne architecture , the ZIF use IQ mixing
but the hetrodyne , in the mixging use the signal osc only

in homodyne the input high frequency signal is directly converted to its baseband equivalent and hence the mixing is very complex... i.e no intermediate frequency is involved...

what is complex mixing?you mean IQ mixing?
It is intended for image rejection

Herterodyne receiver can also use IQ mixing to improve image rejection

the IQ mixing ins't only for image rejection it is also for complex digital modualtion , like QAM , QPSK and so on

khouly

In homo dyne mixing you get directly DC at the output while in Heterodyne you
down convert signal to IF.

So is it true that 99% of the transceiver today are based on homodyne design for its simplicity? Is that true? I was told by someone but I just want to more inputs. Thanks guys.

yeah , i have used alot of IC for CDMA and WCDMA receivers and all are based on the direct conversion architecture "Qualcom , NXP , Silabs " produce them

khouly

ya it is true... though homodyne is a little complex heterodyne has its own set of problems in terms of the detection process....

This is true
Homodyne receivers are preferred because of simplicity & low power & low cost

yeah they are complex , but now the VLSI technology and the DSP can be integrated with the transceiver make the implementation of the direct conversion more and more vesible

khouly

they are depending on system requirement and technology!

what is the advantages and disadvantages of homodyne and heterodyne system?