Channels that Heat Up

TL;DR

This paper investigates a thermal noise channel where heating effects influence noise variance, analyzing capacity at low and high power levels, revealing when heating benefits or limits communication capacity.

Contribution

It introduces a model of a heating-influenced additive noise channel and characterizes its capacity behavior at different power regimes, including conditions for bounded capacity.

Findings

Heating can be beneficial at low power levels.

Capacity remains bounded under certain high-power conditions.

The capacity slope at zero power is explicitly computed.

Abstract

This work considers an additive noise channel where the time-k noise variance is a weighted sum of the channel input powers prior to time k. This channel is motivated by point-to-point communication between two terminals that are embedded in the same chip. Transmission heats up the entire chip and hence increases the thermal noise at the receiver. The capacity of this channel (both with and without feedback) is studied at low transmit powers and at high transmit powers. At low transmit powers, the slope of the capacity-vs-power curve at zero is computed and it is shown that the heating-up effect is beneficial. At high transmit powers, conditions are determined under which the capacity is bounded, i.e., under which the capacity does not grow to infinity as the allowed average power tends to infinity.