title: Comparison of digital signal-signal beat interference compensation techniques in direct-detection subcarrier modulation systems.
abstract: Single-polarization direct-detection transceivers may offer advantages compared to digital coherent technology for some metro, back-haul, access and inter-data center applications since they offer low-cost and complexity solutions. However, a direct-detection receiver introduces nonlinearity upon photo detection, since it is a square-law device, which results in signal distortion due to signal-signal beat interference (SSBI). Consequently, it is desirable to develop effective and low-cost SSBI compensation techniques to improve the performance of such transceivers. In this paper, we compare the performance of a number of recently proposed digital signal processing-based SSBI compensation schemes, including the use of single- and two-stage linearization filters, an iterative linearization filter and a SSBI estimation and cancellation technique. Their performance is assessed experimentally using a 7 × 25 Gb/s wavelength division multiplexed (WDM) single-sideband 16-QAM Nyquist-subcarrier modulation system operating at a net information spectral density of 2.3 (b/s)/Hz.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Li
authors.forename: M Sezer
authors.initials: MS
authors.lastname: Erkilinc
authors.forename: Lidia
authors.initials: L
authors.lastname: Galdino
authors.forename: Kai
authors.initials: K
authors.lastname: Shi
authors.forename: Benn C
authors.initials: BC
authors.lastname: Thomsen
authors.forename: Polina
authors.initials: P
authors.lastname: Bayvel
authors.forename: Robert I
authors.initials: RI
authors.lastname: Killey