Optical communication using micro corner cube reflectors

Chu, Patrick; Lo, Nanping R.; Berg, E.; Pister, Kristofer S. J.

doi:10.1109/memsys.1997.581852

Cited by 49 publications

(27 citation statements)

References 5 publications

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“…Beamforming is a signal processing technique that increases the receiver's ability to enhance the desired signal relative to interference and background noise. For example, free-space optical telecommunication smart receivers have been used recently for many applications such as indoor high-speed wireless communication [1][2][3][4][5] . In such systems, infrared (IR) signals offers several advantages over radio signals: (a) IR transmitters and receivers are capable of achieving higher bit rates at lower cost, (b) the IR spectral region has virtually unlimited bandwidth, and (c) IR transmission cannot be intercepted outside the room from which it originated, since IR radiation is blocked by walls and other opaque barriers.…”

Section: Introductionmentioning

confidence: 99%

Smart optical receiver for beamforming and enhancement of field of view in LADAR systems

et al. 2008

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY) ABSTRACTWe propose using the smart antenna principle as the basis of a new design for smart optical receivers in LADAR systems. This paper demonstrates the feasibility of designing a LADAR system with a receiver consisting of an array of photodetectors, which leads to field-of-view enhancement and beamforming by fusing streams of video information received from the detectors. As a proof of concept, we demonstrate this design by fusing several video information streams from different fields of view using our Mathworks Simulink® model. The fusion algorithm uses the fuzzy logic maximum operation on the data output from the cameras. SUBJECT TERMS ABSTRACTWe propose using the smart antenna principle as the basis of a new design for smart optical receivers in LADAR systems. This paper demonstrates the feasibility of designing a LADAR system with a receiver consisting of an array of photodetectors, which leads to field-of-view enhancement and beamforming by fusing streams of video information received from the detectors. As a proof of concept, we demonstrate this design by fusing several video information streams from different fields of view using our Mathworks Simulink ® model. The fusion algorithm uses the fuzzy logic maximum operation on the data output from the cameras.

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Section: Introductionmentioning

confidence: 99%

Smart optical receiver for beamforming and enhancement of field of view in LADAR systems

et al. 2008

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“…Recently, free-space optical communication has attracted considerable attention for a variety of applications [1][2][3][4][5][6][7][8]. Because of the complexity associated with phase or frequency modulation, current free-space optical communication systems typically use intensity modulation with direct detection (IM/DD).…”

Section: Introductionmentioning

confidence: 99%

“…The simulated BER (lines with circles) and the approximate upper bound (lines without circles) for(7,4) Hamming codes versus average SNR. The log-amplitude variance σ X = 0.2 and the ratio of the adjacent codeword bit interval T to the coherence time of turbulence-induced fading (T /τ 0 ) is chosen to be 0.001, 0.4, and 1, respectively.…”

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confidence: 99%

Communication techniques and coding for atmospheric turbulence channels

Zhu

Kahn

2007

J Optic Comm Rep

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In free-space optical communication links, atmospheric turbulence causes fluctuations in both the intensity and the phase of the received light signal, impairing link performance. In this paper, we describe several communication techniques to mitigate turbulence-induced intensity fluctuations, i.e., signal fading. These techniques are applicable in the regime in which the receiver aperture is smaller than the correlation length of the fading, and the observation interval is shorter than the correlation time of the fading. We assume that the receiver has no knowledge of the instantaneous fading state. The techniques we consider are based on the statistical properties of fading, as functions of both temporal and spatial coordinates. Our approaches can be divided into two categories: temporal domain techniques and spatial domain techniques.In the spatial domain techniques, one must employ at least two receivers to collect the signal light at different positions or from different spatial angles. Spatial diversity reception with multiple receivers can be used to overcome turbulence-induced fading. When it is not possible to place the receivers sufficiently far apart, the fading at different receivers is correlated, reducing the diversity gain. We describe a ML detection technique to reduce the diversity gain penalty caused by such fading correlation.In the temporal domain techniques, one employs a single receiver. When the receiver knows only the marginal statistics of the fading, a symbol-by-symbol ML detector can be used to optimize performance. When the receiver also knows the temporal correlation of the fading, maximum-likelihood sequence detection (MLSD) can be employed, yielding a further performance improvement, but at the cost of very high complexity. We describe two reduced-complexity implementations of the MLSD, which 364 Xiaoming Zhu and Joseph M. Kahn make use of a single-step Markov chain model for the fading correlation in conjunction with per-survivor processing. Next, we also investigate the performance of using error-control coding and pilot symbol-assisted detection schemes through atmospheric turbulence channels.

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“…the command and control with information for fast decisions. Retrocommunication is a technique that has attracted interest recently [1,2,3,4]. Retrocommunication is based on the principle that an interrogating laser is used to extract information from a retromodulating receiver where the laser light is modulated and reflected (in the same direction) back to the transmitting unit ( Figure 1).…”

Section: Introductionmentioning

confidence: 99%

A novel free-space retrocommunication link

et al. 2004

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Retrocommunication is a new technique for asymmetric free-space optical communication that has attracted interest during recent years. Novel technologies such as multiple quantum well (MQW) optical modulators and non-mechanical laser beam steering and tracking have been studied for implementation in a retrocommunication link. Large and small aperture reflective AlGaAs/GaAs MQW modulators were optimised and fabricated. The modulators exhibit high contrast ratios (from 5 to 100) and high modulation rates (up to 16 Mbit/s). A retroreceiver consisting of four large aperture MQW modulators, associated optics and drive electronics was fabricated. Nematic liquid crystal spatial light modulators have been evaluated, characterised for beam steering and tracking and implemented in a transceiver. Small area MQW modulators, used in focal plane configurations, were studied for static communication links. Results from a novel retrocommunication link utilising a retroreceiver and non-mechanical laser beam steering and tracking will be presented. Bit rates of 8 Mbit/s were observed during non-mechanical tracking of a moving retroreceiver over 100 m range. The demonstrator system was capable of transferring audio-, real-time images or bit streams. The demonstrated principles show promising features for future low weight free-space communication links. Performance calculations including requirements for a retrocommunication link using MQW modulators and non-mechanical beam steering are discussed.

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Optical communication using micro corner cube reflectors

Cited by 49 publications

References 5 publications

Smart optical receiver for beamforming and enhancement of field of view in LADAR systems

Smart optical receiver for beamforming and enhancement of field of view in LADAR systems

Communication techniques and coding for atmospheric turbulence channels

A novel free-space retrocommunication link

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