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SINR-Based Adaptive Modulation Simulator


SINR-Based Adaptive Modulation

High Power
Low Congestion
Calculated SINR
0 dB
Active Modulation
BPSK
Efficiency (bps/Hz)
0

Simulation Workflow

1. Channel Measurement: The receiver estimates the Desired Signal Power (S), the power from interfering towers (I), and the background thermal noise (N).

2. SINR Calculation: The system computes the SINR. Notice that even if the Signal is strong, increasing Interference will force the system to drop from 16-QAM to BPSK to maintain the link.

3. Feedback (CQI): In a real system, the receiver sends a Channel Quality Indicator (CQI) back to the transmitter, which then updates the modulation order for the next set of "Yellow Sticks" (Symbol Durations).

Mathematical Framework

The SINR (Signal to Interference plus Noise Ratio) is defined as:

SINRlinear = S / (I + N)

Converted to decibels:

SINRdB = 10 · log10(S / (I + N))

Where S is the received signal power, I is the sum of interference powers from other cells, and N is the thermal noise power. This ratio determines the maximum possible Spectral Efficiency.


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