Data rate limitation in modulated Johnson noise communication
Problem
The paper proposes a communication technique using modulated Johnson noise, yet experimental results reveal very low data rates (about 26 bps at 1.5 m, falling to 22 bps at 4.5 m) and question its practicality because of antenna and power constraints, as well as skepticism about whether the approach violates basic thermodynamic principles.
Pain points
- Throughput only about 26 bps at 1.5 m, dropping to 22 bps at 4.5 m
- Antenna and power constraints require specific RF switches (e.g., ADG90x), adding noise and complexity
- Questions about energy source, seemingly violating the second law of thermodynamics
- Interference and decoding difficulty in multi‑transmitter real‑world scenarios
- Doubts about practical use cases, lacking clear commercial or engineering demand
Questions to verify
- Can the data rate be increased to at least 100 bps in a real deployment?
- Is there a cost‑effective antenna or RF switch solution that can reduce noise?
- How will the system's decoding performance be affected in multi‑user or non‑ideal environments?
Evidence
quote
26 bps at 1.5 m: And what exactly do we expect to carry with this communication channel? If you add horned antennas it becomes a ridiculous design just to gain a few more bytes. If you add antenna arrays then it's no longer cheap. Your transmitter's output power is basically hard limited by Boltzmann constant, so just increasing range means you will have a bad time decoding it. Digital tricks, cryogenics... maybe a few more bytes, but is it enough?I'm really struggling to see if this can be useful for anything.
quote
Shouldn't this be impossible by the second law of thermodynamics? Receiving more energy when a resistor in thermal equilibrium is connected to an antenna seemingly implies that energy gets transferred from an antenna with a resistor to a an antenna without a resistor, even at thermal equilibrium.
Disclaimer: this card is distilled by AI from community discussions as “pain point evidence”. It is a starting point for need analysis and validation, not a “validated market need”. AI has analytical limits; please open the original discussion above to manually verify before key decisions.