Raptor Code based on punctured LDPC for Secrecy in Massive MiMo

Abstract

In the future Fifth-Generation networks, the eavesdropping is a critical threat due to their broadcast-based transmission. This problem can be addressed with the cryptographic protocols. However, this method is complex and difficult because of the dynamic topology of wireless networks, which does not allow an efficient management of security keys. As a complement solution, Physical-layer security (PLS) is integrated to enhance secrecy in wireless networks. The PLS exploits the schemes features of this layer, namely the modulation, Massive Multi-Input Multi-Output(m-MiMo) and channel coding. The fountain code is one of those systems where the secrecy is provided when the destination retrieves packets encoded before the intruder. Nevertheless, the secrecy can not be guaranteed when eavesdropper uses large number of the antennas as in the m-MiMo. The feature of m-MiMo should be considered to secure main channel with fountain codes. Therefore, we propose to use Raptor code which is a class of fountain code, aided by an Artificial noise (AN) and the punctuated data to reduce the efficient of intruder channel. This allows the main channel to retrieve the signal before eavesdropper. The numerical results show that using Raptor code in massive MiMo enhances the reliability and the security on the channel of legitimate user, while minimizes the abilities of intruders to spy on data.