Free-space optical communications with channel shortening filter and viterbi equalizer

Sangwoo Lee, Mohsen Kavehrad

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


This paper is about signal processing techniques for airborne free-space optical (FSO) wireless communications through clouds. FSO channel is known to be accompanied by multi-scattering, which causes severe intersymbol interference. Unlike traditional FSO systems relying on optical signal processing devices, this research paper investigates the feasibility of digital signal processing schemes applied to FSO. By having a channel shortening equalizer (CSE or TEQ for time equalization) at the transmitter and a Viterbi equalizer at the receiver, reliable communication at low-to-mid level optical thickness values is shown to be feasible. We also propose how existing TEQ algorithms can be modified to fit into TEQ-in-transmitter configurations. Performance is evaluated in BER, and compared with conventional equalizations.

Original languageEnglish (US)
Pages (from-to)185-196
Number of pages12
JournalInternational Journal of Wireless Information Networks
Issue number4
StatePublished - Dec 2009

All Science Journal Classification (ASJC) codes

  • Hardware and Architecture
  • Computer Networks and Communications
  • Electrical and Electronic Engineering


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