Verify/lora phy campo

[arlethmichellopez]

Verify RFSAM-LORA-PHY-01 with real US915 reception and decoding sessions

Replace the [FILL: measured CRC-OK frame yield, hard vs soft-decision, at a recorded SNR for one capture] placeholder in ## Field case with actual over-the-air measurements conducted at Electronic Cats, Aguascalientes.

What changed

• ## Field case: Added measured statistics comparing soft vs. hard-decision LoRa demodulation yields across two 30-second US915 capture sessions (FlatSat baseline at 916.0 MHz vs. STM32 verification at 915.0 MHz).
• Frontmatter:
  reviewStatus → verified,
  lastResearched → 2026-09-11.

Measured results

Parameter / Metric	Session 1 (FlatSat Baseline)	Session 2 (STM32 Verification)	Delta / Performance Impact
Center Frequency	916.0 MHz (US915 Ch 8 / Sub-band 2)	915.0 MHz (US915)	—
Bandwidth (BW) / SF	125 kHz / SF7	250 kHz / SF11	—
Estimated SNR	~45.0 dB (Strong / Saturated)	~6.0 dB (Near Sensitivity)	-39.0 dB
Total Visible Frames	12 (30 s IQ capture window)	5 (30 s IQ capture window)	—
Soft-Decision Yield	12 / 12 (100% CRC-OK)	3 / 5 (60% CRC-OK)	-40.0% under low SNR
Hard-Decision Yield	12 / 12 (100% CRC-OK)	1 / 5 (20% CRC-OK)	-80.0% under low SNR
Soft vs. Hard Advantage	No difference (Saturated)	+40 percentage points	Soft-decision advantage

Conditions

• Location: Electronic Cats, Aguascalientes
• Setup Spacing: 1-meter fixed line-of-sight bench test
• SDR Receiver: RTL-SDR (RTL2832U) with stock telescopic antenna
• RF Capture Settings: rtl_sdr -s 1000000 -g 40.2 (30-second raw uint8 I/Q output)
• Spectrum Analyzer: Gqrx 2.17.7
• Flowgraph & Decoder: gr-lora_sdr (GNU Radio Companion flowgraph lora_RX_916.grc) & offline Python script (lora_decode_SF11_fix.py)
• Transceivers Used: Laboratory FlatSat (916 MHz) & STM32F446 + DX-LR30 transceiver (915 MHz, application CRC intentionally corrupted every 2 packets)

Evidence

Session 1 — FlatSat Baseline (916.0 MHz, BW 125 kHz, SF7)

• Gqrx spectrum waterfall showing 916.0 MHz reception:

• GNU Radio flowgraph configured for Soft-Decision (soft_decoding: True):

• GNU Radio flowgraph configured for Hard-Decision (soft_decoding: False):

• Demodulation terminal execution (12/12 CRC-OK, SNR ~45 dB):

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Session 2 — STM32 Verification (915.0 MHz, BW 250 kHz, SF11)

• Gqrx spectrum waterfall showing 915.0 MHz reception:

• Terminal output log for Soft-Decision execution:

• Terminal output log for Hard-Decision execution:

• Metric summary and frame yield validation (3/5 soft vs 1/5 hard):

• Detailed payload logs verifying controlled CRC corruption: