Multilevel Coding for Physical-Layer Security in Optical Networks

Inhalt:
In this paper, multilevel coding in combination with signal shaping is studied for generating both security against a wiretapper and reliability for the legitimate user. Based on the concept of equivalent bit channels defined by the address bits of M-ary modulation schemes, the effects of using higher-order signaling schemes and signal shaping on the capacity and error rate performance are examined. It is shown that transmission over the LSB channel, encoded via punctured LDPC codes, reduces the resulting security gaps significantly in comparison to binary transmission. Results from numerical simulations cover the theoretical considerations.