This paper explores the Achievable Information Rate (AIR) of a diffusive Molecular Communication (MC) channel featuring a fully absorbing receiver that counts the absorbed particles during symbol time intervals (STIs) and resets the counter at the start of each interval. The MC channel, influenced by memory effect, experiences inter-symbol interference (ISI) arising from the molecules' delayed arrival. The channel's memory is quantified as an integer multiple of the STI and a single-sample memoryless detector is employed to mitigate complexity in computing the mutual information (MI). To maximize MI, the detector threshold is optimized under Gaussian approximation of its input. The channel's MI is calculated, considering the influence of ISI, in the context of binary concentration shift keying modulation. Two distinct scenarios were considered; independent and correlated source-generated symbols, the latter modeled as a first-order Markov process. For each communication scenario, two degrees of knowledge: ISI-Aware and ISI-Unaware were considered. Remarkably, it is demonstrated that employing a correlated source enables the attainment of higher capacity. The results indicate that the capacity-achieving input distribution is not necessarily uniform. Notably, when the STI is small, corresponding to the case of strong ISI, the maximum AIR is not achieved through equiprobable symbol transmission.

翻译：本文研究了具有全吸收接收器的扩散分子通信（MC）信道的可达信息率（AIR），该接收器在符号时间间隔（STI）内计数吸收的粒子，并在每个间隔开始时重置计数器。受记忆效应影响的MC信道会因分子延迟到达而产生符号间干扰（ISI）。信道的记忆量被量化为STI的整数倍，并采用单样本无记忆检测器来降低计算互信息（MI）的复杂度。为最大化MI，在检测器输入的高斯近似下优化检测阈值。考虑ISI的影响，在二进制浓度位移键控调制背景下计算信道的MI。考虑了两种不同场景：独立符号和由一阶马尔可夫过程建模的相关源生成符号。对于每种通信场景，考虑了两种知识程度：ISI感知和ISI非感知。值得注意的是，研究表明采用相关源可实现更高的信道容量。结果表明，容量最优的输入分布不一定是均匀的。特别地，当STI较小时（对应于强ISI情况），最大AIR并非通过等概率符号传输实现。