Calculation of the channel capacity of optical phase damping channel with iteration
The optical signal transmitted on a fiber with phase damping is studied. At the limitation of completely damping, we prove that the channel is in fact a classical channel. The completely phase damping channel maps the coherent state to a Poisson distributed state. Classical information is encoded in the parameter of the coherent state, the general input is a probability distribution of coherent states. The transfer matrix is given after the discretion of the parameter of the coherent state. The quantum Holevo quantity (whose maximum gives the channel capacity) is simplified to Shannon mutual information. We calculate the capacity with iteration. The optimal distribution of the input achieve the channel capacity is a probabilistic mixture of vacuum state (zero input) and a wave packet when the total energy is small, other wave packets appear when the total energy increases. The wave packet phenomenon is apparent.
Xiao-yu Chen Liang Han Gui-quan Liu
Lab.of quantum information China Institute of Metrology Hangzhou, 310034, China Dept.of Physics China Institute of Metrology Hangzhou, 310034, China
国际会议
2006年IEEE信息理论国际会议(Proceedings of 2006 IEEE Information Theory Workshop ITW06)
成都
英文
286-288
2006-10-22（万方平台首次上网日期，不代表论文的发表时间）