Space-Time Codes for Optical Fiber Communication with Polarization Multiplexing

Improving PDL Tolerance of Long-Haul PDM-OFDM Systems Using Polarization-Time Coding

“…A 2.2dB coding gain is observed at BER=10 -3 . This value match the obtained gain in [2] and [5]. Furthermore, at an input power of -5dBm, corresponding to a total OSNR of 14 dB, an optimal BER of 5.10 -6 is achieved with the Silver code.…”

“…Space-Time coding or more appropriately PT coding in our context, was proven to be theoretically [2] and experimentally [5] effective in mitigating PDL. The performance of the Golden code and the Silver code, the two best codes for 2x2 MIMO Rayleigh fading channel, was investigated.…”

“…By sending and receiving data on two orthogonal polarizations, we can represent PDM-OFDM systems as 2x2 Multi-Input-Multi-Output (MIMO) channels. Hence, Space-Time (ST) coding can be easily applied to mitigate Polarization Dependent Loss (PDL) [2]. Unlike CD and PMD, PDL is a non-unitary distortion and cannot be efficiently mitigated by the same digital equalization techniques.…”

Polarization-time coding for PDL mitigation in long-haul PolMux OFDM systems

“…In long-haul optical links, PDL is introduced by imperfect optical elements that unequally attenuate the polarization states of the incident signal and induce energy loss and optical signal-to-noise ratio (OSNR) fluctuations. Recently [8][9][10][11], space-time (ST) codes were suggested to mitigate PDL. In wireless MIMO channels, ST coding improves the reliability of the transmission by sending multiple copies of a data symbol to the receiver on different antennas and at different time slots expecting that the symbol will survive the impairments of the channel in a good enough state to allow reliable decoding [12].…”

“…In wireless MIMO channels, ST coding improves the reliability of the transmission by sending multiple copies of a data symbol to the receiver on different antennas and at different time slots expecting that the symbol will survive the impairments of the channel in a good enough state to allow reliable decoding [12]. The performance of ST codes, or more appropriately Polarization-Time (PT) codes in this context, such as the Golden code [13], the Silver code and the Alamouti code were numerically evaluated on an optical channel with PDL [8]. A preliminary experimental demonstration validated the numerical results [9].…”