Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Frequency offset and rotating constellation plot

Status
Not open for further replies.
P

phonenaing

Newbie level 1
Joined
Aug 5, 2011
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,286
Hi greeting..

At digital receiver, carrier frequency offsets cause rotating constellation plot. Can someone explain me how this is visualized in mathematical equation. :)

PN
 

This happens because a frequency offset is modeled as a multiplication by exp(j w t) where w is the offset frequency. On a constellation, rotation is a change of phase, when you multiply by exp(j w t), you are adding to the constellation an instantaneous phase of wt, so the constellation is not actually rotated, but symbols are scattered on constant energy circle. Does this answer your question :) ?
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top