Скачать или смотреть Digital Modulation #7. Types of Constellation Diagram Errors: Quadrature, IQ Imbalance & IQ Offset.

Digital Modulation playlist.
   • Digital Modulation #1. How to Measure Data...  

For access to this presentation materials, membership is required: I need the Material PPT
Sent me an email to [email protected]
If you need the whole playlist material, send me email and we discuss.
Give me some time to response. Thanks.

IQ Imbalance

Difference in gain between the I & Q signal components

Asymmetric constellation. Skewed or Stretched Constellations (non-square shapes)

Quadrature Error

quadrature error is the deviation from angle

for an ideal modulator, the quadrature offset is 0o

skewed constellation phase skew

Imperfect Local Oscillator (LO)

The I and Q carriers may not be exactly 90° apart due to phase imbalances

I/Q Offset / Carrier Leakage

In a constellation diagram, I/Q offset (also known as carrier leakage) refers to a distortion where the entire constellation is shifted away from its ideal origin (0,0 point) due to a DC offset in the I (in-phase) and/or Q (quadrature) channels. 

DC offsets introduced in the I and Q paths