In this paper, we investigate the achievable rate of a diffusive Molecular Communication (MC) channel with fully absorbing receiver, which counts particles absorbed along each symbol interval and resets the counter at every interval (reset-counting). The MC channel is affected by a memory effect and thus inter-symbol interference (ISI), due to the delayed arrival of molecules. To reduce complexity, our analysis is based on measuring the channel memory as an integer number of symbol intervals and on a single-sample memoryless detector. Thus, in our model the effect of released particles remains effective for a limited number of symbol intervals. We optimize the detector threshold for maximizing capacity, approximate as Gaussian the received signal distribution, and calculate the channel mutual information affected by ISI, in the case of binary concentration shift keying modulation. To the best of our knowledge, in literature there are no previous investigations on the achievable rate in this type of system. Our results demonstrate that, in general, the optimal input probability distribution achieving the maximum achievable rate may be not uniform. In particular, when the symbol interval is small (strong ISI), the maximum achievable rate does not occur with equiprobable transmission of bits.

翻译：本文研究了具有全吸收接收机的扩散分子通信信道的可达速率，该接收机在每个符号间隔内统计吸收的粒子数，并在每个间隔结束时重置计数器（重置计数）。由于分子延迟到达，分子信道受到存储效应的影响，从而产生符号间干扰。为降低复杂度，我们的分析基于将信道存储量量化为整数个符号间隔，并采用单样本无记忆检测器。因此，在我们的模型中，释放粒子的效应仅在有限数量的符号间隔内持续有效。我们优化了检测阈值以最大化信道容量，将接收信号分布近似为高斯分布，并计算了在二进制浓度偏移键控调制下受符号间干扰影响的信道互信息。据我们所知，文献中尚无针对此类系统可达速率的先前研究。结果表明，通常实现最大可达速率的最优输入概率分布可能不是均匀的。特别地，当符号间隔较小时（强符号间干扰），最大可达速率并非出现在等概率传输比特的情况下。