光通信的量子极限：级联码和联合检测接收机
On quantum limit of optical communications: concatenated codes and joint-detection receivers
摘要：
当经典的信息是在一个信道上发送的量子状态调制字母，如自由空间光（FSO）信道，达到最终（Holevo）限制信道容量需要接收机进行联合测量长码字块。在最近的工作中，我们展示了一种纯状态信道的接收器，该接收器可以通过在接收到的码字状态上应用单次光学（酉）变换，然后在单调制符号状态空间上同时（但可分离）投影测量来达到最终容量。在本文中，我们研究的最终权衡光子效率和光谱效率的FSO信道。基于我们的一般结果的纯态量子信道，我们展示了一些第一个具体的例子的代码和实验室可实现的联合检测光接收器，可以实现从根本上更高的（超加性）的信道容量比接收器，物理检测每个调制符号一次一个，是由所有传统的（相干或直接检测）光接收器。
英文摘要：
When classical information is sent over a channel with quantum-state modulation alphabet, such as the free-space optical (FSO) channel, attaining the ultimate (Holevo) limit to channel capacity requires the receiver to make joint measurements over long codeword blocks. In recent work, we showed a receiver for a pure-state channel that can attain the ultimate capacity by applying a single-shot optical (unitary) transformation on the received codeword state followed by simultaneous (but separable) projective measurements on the single-modulation-symbol state spaces. In this paper, we study the ultimate tradeoff between photon efficiency and spectral efficiency for the FSO channel. Based on our general results for the pure-state quantum channel, we show some of the first concrete examples of codes and laboratory-realizable joint-detection optical receivers that can achieve fundamentally higher (superadditive) channel capacity than receivers that physically detect each modulation symbol one at a time, as is done by all conventional (coherent or direct-detection) optical receivers.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
