J-QAM
Block Diagram for J-QAM v1.2 (old)

Both the following interactive images are for a setup circa version 1.2.

How the modulator works? (Click on the components below)

Page-1

How the demodulator works? (still need to add more links for the blocks in the picture below, wikipedia is not good with these at all).

Page-1 AGC Descrambler Bit Unstuffer TCM Decoder RX RRC FIR FILTER i i i RX RRC FIR FILTER This is to create a cosine wave sine wave ocilator Adds two number together Down samples by 2 times Modified constant modulus algorithm (very modified) Puts the complex signal to the 4th power. Causes angles to by multiplyed 4 times. Low pass filter to get average point Takes the angle of the given point Rotates the constelation by either 0,90,180,270 Decides what rotation is most likely, and switches DD and AMA Angle difference of recived point and the point that it should be Decides how to adjust the sine wave oscilator Performs complex convolution

 

Jonti Olds
23 Match 2008

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Jonti. Last modified Mon, 31 Aug 2015 06:57:50 GMT.