Short-and medium-haul links in inter-data center, access, and metro networks require cost-effective direct-detection (DD) wavelength division multiplexing (WDM) transceivers offering energy efficiency, high information spectral density (ISD) and dispersion tolerance. Single-sideband orthogonal frequency division multiplexing (SSB-OFDM) with direct detection is a potential solution; however, it suffers a penalty from signal-signal beat interference (SSBI) caused by the square-law photodetection. In this paper, a novel DSP-based SSBI mitigation technique, with lower complexity than previously proposed methods, is proposed and assessed through numerical simulations for the first time. The performance improvement is quantified by simulations of 9 × 112 Gb/s 16-QAM SSB-OFDM signal with a net optical ISD of 2.1 (b/s)/Hz. The performance is shown to be similar to that of the more complex receiver-based iterative SSBI compensation technique. Simulations predict an 8.7 dB reduction in the required OSNR at the 7% overhead HD-FEC threshold, and increases of up to 100% in maximum reach over uncompensated standard singlemode fibre (SSMF) using the proposed simplified SSBI compensation technique.