Fundamental Channel Estimation
Experiment with how a wireless channel (h) distorts a known pilot signal (x) and how we recover it.
Actual Channel (h):
Estimated Channel (Ä¥):
Estimation Error:
Formula: y = hx + n | ĥ = mean(y/x)
1. Received Signal (y)
Notice the rotation (phase shift) and scaling (magnitude) compared to the original pilot at (1,0).
2. Equalized Signal (y / ĥ)
After dividing by our estimate ĥ, the points should cluster back around (1,0).
How the Simulator Works
The Workflow
- Transmit (x): We send a known "Pilot" symbol (1 + 0j).
- Distort (h): The channel rotates and scales the signal.
- Contaminate (n): Random noise is added to the signal.
- Estimate (Ä¥): The receiver calculates the channel by comparing y to x.
- Recover: We divide the received signal by the estimate to "undo" the distortion.
The Math
1. Received Signal:
y = h ⋅ x + n
2. Least Squares Estimate:
ĥ = mean(y / x)
3. Equalization (Recovery):
xest = y / ĥ
*Since our pilot x = 1, the math simplifies to ĥ = mean(y).