Modeling interference between OFDM/OQAM and CP-OFDM: Limitations of the PSD-based model

Abstract

To answer the challenges put out by the next generation of wireless networks (5G), important research efforts have been undertaken during the last few years to find new waveforms that are better spectrally localized and less sensitive to asynchronism effects than the widely deployed Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM). One of the most studied schemes is OFDM-Offset Quadrature Amplitude Modulation (OFDM/OQAM) based on the PHYDYAS filter pulse. In the recent literature, spectrum coexistence between OFDM/OQAM and CP-OFDM is commonly studied based on the Power Spectral Density (PSD) model. In this paper, we show that this approach is flawed and we show that the actual interference injected by OFDM/OQAM systems onto CP-OFDM is much higher than what is classically expected with the PSD based model in the literature. We show that though using OFDM/OQAM in secondary systems is still advantageous, it brings limited gain in the context of coexistence with incumbent CP-OFDM systems.

Coexistence of OFDM and FBMC for Underlay D2D Communication in 5G Networks

“…Interference tables measuring the value of interference injected between different couples of waveforms according to [4]- [6]. model, we are primarily concerned with pathloss, since we wish to evaluate the performance of both waveforms as we vary several distance related parameters such as cluster size, or distance from the BS.…”

“…Fortunately, a number of papers have extensively analysed and precisely modelled the leakage between asynchronous users operating on different parts of the spectrum band, and derived interference tables that we will build our analysis upon [4]- [6]. More precisely, we draw upon the work of [5] to rate the interference from FBMC/OQAM to FBMC/OQAM users, or OFDM to OFDM users.…”

“…More precisely, we draw upon the work of [5] to rate the interference from FBMC/OQAM to FBMC/OQAM users, or OFDM to OFDM users. Additionally, we obtain the interference from OFDM to FBMC/OQAM and from FBMC/OQAM to OFDM according to the recent works of [4] and [6]. These works allow us to rate the value of I{A → B}(l), which corresponds to the interference injected by a subcarrier of waveform A to a subcarrier of waveform B at spectral distance l.…”

“…We build upon our work in [4], which provides interference tables capturing the effects of misaligned D2D users in time and frequency onto OFDMA-based cellular users in the uplink band. We also draw upon the work of [5], [6] in order to characterize the interference imposed between entities utilizing different waveforms.…”

Performance of Fading Channels on Asynchronous OFDM Based Cognitive Radio Networks

“…To the best of the authors knowledge, asynchronous interference can be quantified with the Power Spectral Density (PSD)-based model as in [8]. The PSD is generally used to evaluate the mutual interference between two systems but this method does not consider the real level of interference since the asynchronism is absorbed.…”