🤖 AI Summary
This study addresses the challenge of channel modeling for molecular communication under dynamic electric fields, where analytical tractability is hindered by the coupling of stochastic diffusion and complex boundary conditions, rendering conventional partial differential equation approaches ineffective. The work introduces the Cameron–Martin–Girsanov theorem to this domain for the first time, establishing a stochastic analysis framework based on measure transformation to derive closed-form expressions for the channel impulse response with both fully absorbing and passive spherical receivers. Building on this model, a dynamic waveform optimization mechanism is proposed, reformulating bit error rate minimization as a distance optimization problem and yielding a low-complexity Minimum Residual Probability (MRP) algorithm to mitigate inter-symbol interference. The resulting model accurately captures channel dynamics under time-varying electric fields, and the MRP algorithm achieves near-optimal detection performance, significantly enhancing reception probability.
📝 Abstract
Analytical modeling of field-assisted molecular communication under dynamic electric fields is fundamentally challenging due to the coupling between stochastic transport and complex boundary geometries, which renders conventional partial differential equation (PDE) approaches intractable. In this work, we introduce a stochastic framework based on the Cameron-Martin-Girsanov theorem to address this challenge. By leveraging a change-of-measure technique, we derive analytically tractable channel impulse response (CIR) expressions for both fully-absorbing and passive spherical receivers, where the latter serves as an exact mathematical baseline to validate our framework. Building upon these models, we establish a dynamic waveform design framework for system optimization. Under a maximum a posteriori decision-feedback equalizer (MAP-DFE) framework, we show that the first-slot received probability serves as the primary determinant of the bit error probability (BEP), while inter-symbol interference manifests as higher-order corrections. Exploiting the monotonic response of the fully-absorbing architecture and using the limitations of the passive model to justify this strategic focus, we reformulate BEP minimization into a distance-based optimization problem. We propose a unified, low-complexity Maximize Received Probability (MRP) algorithm, encompassing the Maximize Hitting Probability (MHP) and Maximize Sensing Probability (MSP) methods, to dynamically enhance desired signals and suppress inter-symbol interference. Numerical results validate the accuracy of the proposed modeling approach and demonstrate near-optimal detection performance.