Non-coherent Orthogonal Modulation. Non-coherent implies that phase information is not available to the receiver As a result, zero phase of the receiver can mean any phase of the transmitter
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Since the equation
Represent the envelope of the received signal we can demodulate the received signal using an envelope detector as shown in the next slide
The envelope detector finds the square root of
An alternate way to show the equivalence between the non-coherent matched filter using envelope detector and the non-coherent detector using quadrature detector is illustrated in mathematically in the next few slides
Instead of finding the phase of the signal on the interval 0<t≤Tb. This receiver determines the phase difference between adjacent time intervals.
If “1” is sent, the phase remains unchanged
If “0” is sent, the phase changed by 180◦
Similary we can define for the transmission of symbol 0 for DPSK encoding over the time interval as
Let the binary sequence represents the binary data to be transmitted using DPSK
Let the sequence represents the differentially encoded sequence
The encoding rule can be as follows (there is a reference bit as explained in Ch.3)
Consider the binary sequence shown below find the differentially encoded sequence and the transmitted phase of the carrier
Differential PSK modulator can be realized by the block diagram shown below, where (Xnor operation)