Secure distributed estimation of radio environment map in hierarchical wireless Cognitive Radio networks

Radio Environment Map (REM) is a map which indicates the radio signal strength (RSS) over a geographical region. With the help of REM, Cognitive Radio (CR) users can opportunistically access the licensed spectrum. Distributed cooperative REM estimation is vulnerable to malicious sensors that submits false sensing reports. In this paper, we develop a secure distributed scheme to estimate the REM in hierarchical wireless CR networks. We formulate the estimation process as a LS problem with two ii-norm constraints using the basis pursuit approach. Reputation factors are introduced to further improve the estimation accuracy. Our scheme enables joint valid estimation result and malicious sensor identification. The performance of the proposed scheme is confirmed by extensive simulation studies.