Photon information efficient communication through atmospheric turbulence
High photon-efficiency (many bits/photon) optical communication is possible with pulse-position modulation and direct detection, and high spectral efficiency (many bits/sec-Hz) optical communication is possible with quadrature-amplitude modulation and coherent detection. These high efficiencies, how...
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| Format: | Article |
| Language: | en_US |
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SPIE
2014
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| Online Access: | http://hdl.handle.net/1721.1/90849 https://orcid.org/0000-0002-6094-5861 https://orcid.org/0000-0001-5634-3123 |
| _version_ | 1826192930900017152 |
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| author | Chandrasekaran, Nivedita Shapiro, Jeffrey H. Wang, Ligong |
| author2 | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science |
| author_facet | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Chandrasekaran, Nivedita Shapiro, Jeffrey H. Wang, Ligong |
| author_sort | Chandrasekaran, Nivedita |
| collection | MIT |
| description | High photon-efficiency (many bits/photon) optical communication is possible with pulse-position modulation and direct detection, and high spectral efficiency (many bits/sec-Hz) optical communication is possible with quadrature-amplitude modulation and coherent detection. These high efficiencies, however, cannot be achieved simultaneously unless multiple spatial modes are employed. Previous work for the vacuum-propagation channel has shown that achieving 10 bits/photon and 5 bits/sec-Hz is impossible with coherent detection, and it requires 189 low diffraction-loss spatial modes at the ultimate Holevo limit, and 4500 such modes at the Shannon limit for on-off keying with direct detection. For terrestrial propagation paths, however, the effects of atmospheric turbulence must be factored into the photon and spectral efficiency assessments. This paper accomplishes that goal by presenting upper and lower bounds on the turbulent channel’s ergodic Holevo capacity for M-mode systems whose transmitters use either focused-beam, Hermite-Gaussian (HG), or Laguerre-Gaussian (LG) modes, and whose receivers do M-mode detection either with or without adaptive optics. The bounds show that use of adaptive optics will not be necessary for achieving high photon efficiency and high spectral efficiency through atmospheric turbulence, although receivers which do not use adaptive optics will need to cope with considerable crosstalk between the spatial patterns produced in their entrance pupils by the M-mode transmitter. The bounds also show the exact theoretical equivalence of the HG and LG mode sets for this application, generalizing a result previously established for the vacuum-propagation channel. Finally, our results show that the FB modes outperform the HG and LG modes in operation with and without adaptive optics. |
| first_indexed | 2024-09-23T09:31:02Z |
| format | Article |
| id | mit-1721.1/90849 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T09:31:02Z |
| publishDate | 2014 |
| publisher | SPIE |
| record_format | dspace |
| spelling | mit-1721.1/908492022-09-26T11:56:52Z Photon information efficient communication through atmospheric turbulence Chandrasekaran, Nivedita Shapiro, Jeffrey H. Wang, Ligong Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology. Research Laboratory of Electronics Chandrasekaran, Nivedita Shapiro, Jeffrey H. Wang, Ligong High photon-efficiency (many bits/photon) optical communication is possible with pulse-position modulation and direct detection, and high spectral efficiency (many bits/sec-Hz) optical communication is possible with quadrature-amplitude modulation and coherent detection. These high efficiencies, however, cannot be achieved simultaneously unless multiple spatial modes are employed. Previous work for the vacuum-propagation channel has shown that achieving 10 bits/photon and 5 bits/sec-Hz is impossible with coherent detection, and it requires 189 low diffraction-loss spatial modes at the ultimate Holevo limit, and 4500 such modes at the Shannon limit for on-off keying with direct detection. For terrestrial propagation paths, however, the effects of atmospheric turbulence must be factored into the photon and spectral efficiency assessments. This paper accomplishes that goal by presenting upper and lower bounds on the turbulent channel’s ergodic Holevo capacity for M-mode systems whose transmitters use either focused-beam, Hermite-Gaussian (HG), or Laguerre-Gaussian (LG) modes, and whose receivers do M-mode detection either with or without adaptive optics. The bounds show that use of adaptive optics will not be necessary for achieving high photon efficiency and high spectral efficiency through atmospheric turbulence, although receivers which do not use adaptive optics will need to cope with considerable crosstalk between the spatial patterns produced in their entrance pupils by the M-mode transmitter. The bounds also show the exact theoretical equivalence of the HG and LG mode sets for this application, generalizing a result previously established for the vacuum-propagation channel. Finally, our results show that the FB modes outperform the HG and LG modes in operation with and without adaptive optics. National Science Foundation (U.S.). Integrative Graduate Education and Research Traineeship (Interdisciplinary Quantum Information Science and Engineering) United States. Defense Advanced Research Projects Agency. Information in a Photon (InPho) Program (DARPA/CMO Contract HR0011-10-C-1059) 2014-10-09T18:43:38Z 2014-10-09T18:43:38Z 2012-10 Article http://purl.org/eprint/type/ConferencePaper 0277-786X http://hdl.handle.net/1721.1/90849 Chandrasekaran, Nivedita, Jeffrey H. Shapiro, and Ligong Wang. “Photon Information Efficient Communication through Atmospheric Turbulence.” Edited by Ronald E. Meyers, Yanhua Shih, and Keith S. Deacon. Quantum Communications and Quantum Imaging X (October 15, 2012). https://orcid.org/0000-0002-6094-5861 https://orcid.org/0000-0001-5634-3123 en_US http://dx.doi.org/10.1117/12.929832 Proceedings of SPIE Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf SPIE SPIE |
| spellingShingle | Chandrasekaran, Nivedita Shapiro, Jeffrey H. Wang, Ligong Photon information efficient communication through atmospheric turbulence |
| title | Photon information efficient communication through atmospheric turbulence |
| title_full | Photon information efficient communication through atmospheric turbulence |
| title_fullStr | Photon information efficient communication through atmospheric turbulence |
| title_full_unstemmed | Photon information efficient communication through atmospheric turbulence |
| title_short | Photon information efficient communication through atmospheric turbulence |
| title_sort | photon information efficient communication through atmospheric turbulence |
| url | http://hdl.handle.net/1721.1/90849 https://orcid.org/0000-0002-6094-5861 https://orcid.org/0000-0001-5634-3123 |
| work_keys_str_mv | AT chandrasekarannivedita photoninformationefficientcommunicationthroughatmosphericturbulence AT shapirojeffreyh photoninformationefficientcommunicationthroughatmosphericturbulence AT wangligong photoninformationefficientcommunicationthroughatmosphericturbulence |