  In this paper, we propose a novel inter-symbol interference (ISI) mitigation
scheme for molecular communication via diffusion (MCvD) systems with the
optimal detection interval. Its rationale is to exploit the discarded duration
(i.e., the symbol duration outside this optimal interval) to relieve ISI in the
target system. Following this idea, we formulate an objective function to
quantify the impact of the discarded time on bit error rate (BER) performance.
Besides, an optimally reusable interval within the discarded duration is
derived in closed form, which applies to both the absorbing and passive
receivers. Finally, numerical results validate our analysis and show that for
the considered MCvD system, significant BER improvements can be achieved by
using the derived reusable duration.
