Vestigial Sideband OFDM for Adjacent Channel Coexistence of Wireless Networks with Radio Astronomy

Robust interference avoidance will be a critical feature of wireless communication systems in the future. Avoiding interference to users on adjacent bands is of particular concern with systems employing Orthogonal Frequency Division Multiplexing (OFDM) due to the side lobes of the subcarriers. A number of techniques can be found in the literature for reducing the Out-of-Band (OOB) radiation from OFDM transmitters. In this paper, we consider a scenario wherein OOB radiation must be mitigated on only one side of the OFDM spectrum. We show that a technique derived from analog Vestigial Sideband Modulation (VSB) can provide significant OOB suppression while still retaining most of the implementation advantages of standard OFDM. This technique is suitable for cellular networks in the L- band, where certain frequencies reserved for scientific use need better OOB protection than other frequencies.