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Updated: May 15, 2026

Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping
Published on: March 20, 2017
Digital coherent superposition for performance improvement of spatially multiplexed coherent optical OFDM
Xiang Liu1, S Chandrasekhar, A H Gnauck
1Bell Labs, Alcatel-Lucent, 791 Holmdel-Keyport Road, Holmdel, New Jersey 07733, USA. xiang.liu@alcatel-lucent.com
Abstract:
We demonstrate the use of digital coherent superposition to improve the performance of space-division-multiplexed (SDM) 676-Gb/s OFDM-16QAM superchannels, achieving ~4 dB improvement in OSNR by using two SDM copies and 1075-km (14 x 76.8 km) transmission over a seven-core-fiber with an effective aggregate spectral efficiency of 23.7 b/s/Hz. We further show that the performance improvement from the coherent superposition is retained in the nonlinear transmission regime through coordinated scrambling of signal constellations at the transmitter and appropriate unscrambling at the receiver, by using a series of simple scrambling functions.
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