waveform · coherence · fidelity · BER

Signal Lab

Interactive analyzer for AI- and quantum-secured links across the Space-Ground Integrated Network. Tune two waveforms and observe coherence, quantum fidelity, SNR and modulation-aware BER in real time.

Carrier ψ₁

amplitude A₁1
frequency f₁ (Hz)4
phase φ₁ (°)0

Carrier ψ₂

amplitude A₂0.85
frequency f₂ (Hz)4
phase φ₂ (°)45

Channel

noise σ0.08
phasor superposition
ψ₁ψ₂

coherence ρ

0.712

Pearson xcorr

fidelity F

0.8574

|⟨ψ₁|ψ₂⟩|²

SNR

23.7 dB

σ²=2.13e-3

BER · QPSK

0.00e+0

2 b/sym

QBER

9.13%

BB84 threshold 11%

RMS₁

0.705

√⟨s₁²⟩

RMS₂

0.607

√⟨s₂²⟩

throughput

8.0 b/τ

k·fₛ

FFT spectrum
N
win
K=64 · Δf=0.0078

peak f₁

bin 2

mag 0.501

peak f₂

bin 2

mag 0.427

−3 dB BW

0 bins

2…2

Bloch sphere
F=0.857 · Δφ=45°
|0⟩|1⟩+x−x

|ψ⟩ = cos(θ/2)|0⟩ + e^{iφ} sin(θ/2)|1⟩   ·   θ ← π·clamp(A/2)

QKD channel · BB84
QBER abort · 11%

ticks

0

rolling 40

avg QBER

0.00%

ok

final key

—

session

—

clean

Drives simulateProtocol(module:qkd) on a 0.9 s loop; lab noise σ and fidelity F bias the reported QBER.

formulae · live
s(t) = A · sin(2π f t + φ)
P_signal = A²/2 P_noise = σ²/3
SNR_dB = 10·log₁₀( P_s / P_n )
ρ(s₁,s₂) = Σ(s₁−μ₁)(s₂−μ₂) / √(Σd₁²·Σd₂²)
F(ψ₁,ψ₂) = |⟨ψ₁|ψ₂⟩|² ∈ [0,1]
BER_BPSK = Q(√(2·SNR))
BER_QAM-M ≈ (4/log₂M)(1−1/√M)·Q(√(3·SNR/(M−1)))
QBER ≈ ½(1−F) + ¼σ (BB84 abort > 0.11)

Multi-Orbit SGIN Tier

propagation: τ ≈ 2·d / c
LEO500–2,000 km

Real-time IoT & edge AI inference

RTT ~ 20–40 ms

MEO~10,000 km

GNSS time sync for IoT timestamps

RTT ~ 60–120 ms

GEO~35,786 km

Broadcast, OTA updates, weather data

RTT ~ ≥ 240 ms

IoT Edge Protocol Matrix

protocolbandrangedata ratepower
LoRa / LoRaWANSub-GHz2–15 km0.3–50 kbpsvery low
NB-IoTLTE in-band1–10 km20–250 kbpslow
Zigbee2.4 GHz10–100 m250 kbpslow
BLE 5.x2.4 GHz10–240 m1–2 Mbpsvery low
MQTTTCP/IPglobalapp-layern/a
CoAPUDP/IPglobalapp-layern/a

Dynamic DTN

AI predicts blackout windows and bundles packets until the next pass — replacing TCP retries that break under high BER.

Neural Waveform Shaping

Switch QPSK → 16-QAM → 64-QAM in flight as SNR improves; revert under solar / atmospheric turbulence.

Semantic Compression

Edge inference replaces the 4K stream with a 200-byte event: {wildfire,[lat,lng],t}.