An Assessment of OFDM Carrier Frequency Offset Synchronization Security for 4G Systems

Orthogonal Frequency Division Multiplexing (OFDM) is becoming widely deployed in fourth generation (4G) wireless communications systems. Synchronization between a transmitter and receiver is required for coherent demodulation of OFDM symbols, but this process is extremely fragile and susceptible to attacks from malicious third parties. Carrier frequency offset estimation and correction in particular is both prerequisite to demodulation and extremely sensitive to errors. In this work, we address security concerns and assess the performance of the popular maximum likelihood (ML) estimation algorithm developed in [1] in the presence of adversarial communications systems. We present performance metrics for OFDM frequency synchronization versus various physical attacks and assess key security improvements.