A cognitive radio application of OM-OFDM for implementation in DVB-T2

In this paper, the authors have proposed using offset modulation (OM-OFDM) for cognitive radio applications. An examination of the spectrum characteristics of an OM-OFDM transmission demonstrates its strong detection characteristics. Thereafter the methodology behind energy detection is discussed, and a simplified theoretical closed form expression for the probability of a missed detection (P_md) and the probability of a false alarm (P_fa) for an unknown deterministic signal is derived. Then, by using energy detection, the OM-OFDM method is shown to operate at a 15 dB lower average signal-to-noise ratio (SNR) value than an OFDM transmission, while offering similar detection characteristics as an OFDM transmission under Rayleigh fading conditions. The receiver operating characteristic curves in addition indicate that the P_md for an OM-OFDM transmission is 1.3×10^-1 and the P_md for an OFDM transmission is 0.85 (at a P_fa = 10^-1 and average SNR of -5dB) for Rayleigh fading conditions.