Forward Error Correction Encoding On The Multiple Input/Multiple Output Free Space Optical Communications Channel
Abstract
As a high bandwidth, narrow beamwidth channel, free space optical (FSO) communications can potentially achieve high data rates with a low probability of detection and intercept. However, in addition to the additive white Gaussian noise typical of radio frequency communications, atmospheric turbulence adds random, relatively long duration fades to the channel, which significantly decrease overall throughput. This thesis explores how various forward error correction (FEC) techniques affect the channel capacity of a multiple input/multiple output (MIMO) system. A statistical model of the channel is developed from the existing literature. Thirteen coding and modulation schemes are implemented in software and tested against this channel model under different simulated levels of noise and turbulence. Codes are compared by characteristics such as energy per bit and outage thresholds to determine which characteristics of the different codes most critically affect performance. Key performance indicators for each code include average bit error rate, overall throughput, and variability. A recommendation is made to implement variable-level coding in future advanced technology demonstrators or prototypes developed for the FSOMIMO system.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2019
- Accession Number
- AD1080302
Entities
People
- Paul C. Keeley
Organizations
- Naval Postgraduate School