Inspiration

As we transition from 5G to 6G, the Terahertz (THz) band \(0.1–10\ \mathrm{THz}\) is the final frontier for unlocking ultra-fast, terabit-per-second communication. However, THz waves are notoriously fragile. They suffer from:

  • Extreme free-space path loss
  • Heavy molecular absorption by water vapor in the atmosphere
  • Severe scattering from rough surfaces

Traditional mathematical channel estimation techniques are simply too slow and computationally heavy to track these rapidly fluctuating channels.

We were inspired by the potential of Deep Learning to bypass these hardware limitations. We wanted to build an AI that could "see" through physical distortions and instantly predict channel characteristics, making real-time 6G a reality.


What it does

KKNet-6G: HyperChannel Intelligence

KKNet-6G is an interactive, AI-driven physics lab and inference engine for next-generation wireless networks.

Our project simulates the brutal physical conditions of the THz spectrum on the fly. Users can interactively adjust:

  • Communication Distance
  • Atmospheric Humidity
  • Wall Roughness

As the physical environment changes, our pre-trained neural network instantly processes the raw received time-domain intensity pulse:

$$ I(t) $$

and successfully reconstructs the complex frequency-domain channel response:

$$ H(f) $$

"It achieves stunning accuracy in real-time, completely bypassing traditional, slow mathematical estimators."


How we built it

The project was built in three main phases:


1. The Physics Simulator

We built a deterministic simulator capable of generating realistic THz fading channels.

The simulator incorporates complex physics equations covering:

  • Line-of-Sight attenuation
  • NLoS multipath reflections
  • Molecular absorption peaks

2. The Deep Learning Engine

We trained KKNet, a 1D Convolutional Neural Network (CNN).

The model learns to map:

  • A noisy 1000-point intensity vector
  • Into a high-fidelity 400-point frequency vector

3. The Interactive Dashboard

We used Streamlit to integrate the physics simulator and the PyTorch inference engine together.

We built:

  • Dynamic Plotly visualizations
  • Real-time spectrum graphs
  • Effective CQI evaluation metrics

This allows users to visually inspect:

  • Frequency notches
  • Absorption peaks
  • Multipath fading behavior

in real time.


Challenges we ran into

One of our biggest hurdles was evaluating the model's accuracy correctly.

In wireless communication, signal power drops exponentially with distance according to the Free Space Path Loss (FSPL) equation:

$$ \mathrm{FSPL} = \left( \frac{c}{4\pi d f} \right)^2 $$

Where:

  • \(c\) = speed of light
  • \(d\) = communication distance
  • \(f\) = carrier frequency

When testing the AI across different distances, we discovered that the raw prediction error was unfairly skewed by absolute amplitude loss — even when the AI perfectly reconstructed the shape of the channel.

To solve this, we implemented an Automatic Gain Control (AGC) normalization step, similar to real wireless receivers.


AGC Normalization

# AGC Normalization to correct scalar path loss

gain_factor = torch.sqrt(
    torch.sum(torch.abs(H_f_true)**2) /
    torch.sum(torch.abs(Y_pred)**2)
)

Y_pred = Y_pred * gain_factor

Built With

  • 1d-convolutional-neural-networks-(1d-cnn)
  • automatic-gain-control-(agc)-normalization
  • batch-normalization
  • deep-learning
  • dropout-regularization
  • frequency-domain-channel-estimation
  • github
  • line-of-sight-(los)-&-non-line-of-sight-(nlos)-propagation-modeling
  • machine-learning
  • matplotlib
  • neural-network-inference
  • numpy
  • pandas
  • plotly
  • python
  • pytorch
  • residual-blocks-(resnet-architecture)
  • rf-signal-processing
  • scientific-computing
  • scipy
  • signal-to-noise-ratio-(snr)-modeling
  • streamlit
  • terahertz-(thz)-multipath-fading-simulation
  • wireless-channel-modeling
  • yaml
  • z-score-standardization
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