Non-uniform hierarchical modulation for wireless communication in smart grid

The deregulation and liberalization of power market allows greater integration of renewable power resources at all stages of electrical networks but it makes the balance between supply and demand more difficult to reach. Thus, efficient and reliable communications between electrical network nodes must be guaranteed in order to dynamically use the power system as optimally as possible. The electrical protection decisions and real time pricing are among the categories of power system information. However, these categories have different priorities depending on their importance in the whole power system. Communication system must then take into consideration such requirements. This paper proposes the use of wireless links to transmit these information differentially protected by using non-uniform hierarchical quadrature amplitude modulation (16-QAM) where high (low) reliable symbols are assigned to critical (basic) information.