TY - GEN
T1 - Modulation format recognition scheme using orthogonal codewords for wavelength division multiplexing system
AU - Mao, Rui
AU - Zhang, Qi
AU - Xin, Xiangjun
AU - Liu, Naijin
AU - Zhang, Wei
AU - Tian, Qinghua
AU - Tian, Feng
AU - Tao, Ying
N1 - Publisher Copyright:
© 2019 SPIE.
PY - 2019
Y1 - 2019
N2 - A modulation format identification (MFI) scheme based on orthogonal coding scheme is proposed to solve the modulation format identification problem in wavelength division multiplexing (WDM) systems. The scheme uses sidebands to carry orthogonally encoded modulation format information. The basic orthogonal codeword is generated by the Hadamard matrix, and the codewords that are not equal to other codewords after the cyclic shift are selected. The receiving end decodes the modulation format information by using mutual information. We calculate the difference between the maximum and minimum values of the mutual information between the received symbols after cyclic shifting and the standard codewords to make the proposed scheme more robust. We numerically simulated the proposed scheme in a wavelength division multiplexing system, where its channels carry 12.5 Gbaud 4/16/64 QAM and 8/16 PSK. The simulation results show that the modulation format information in the sideband has little effect on the main band information. In the absence of symbol calibration, the receiver can still recover modulation format information from the sideband information with a high accuracy rate. Compared with the MFI algorithm based on Stokes space and the MFI based on signal amplitude performance, the proposed MFI still performs well at low OSNR, although it occupies some bandwidth resources. Moreover, this solution only requires a small number of symbols for decision, so it can achieve fast response requiring little extra storage space.
AB - A modulation format identification (MFI) scheme based on orthogonal coding scheme is proposed to solve the modulation format identification problem in wavelength division multiplexing (WDM) systems. The scheme uses sidebands to carry orthogonally encoded modulation format information. The basic orthogonal codeword is generated by the Hadamard matrix, and the codewords that are not equal to other codewords after the cyclic shift are selected. The receiving end decodes the modulation format information by using mutual information. We calculate the difference between the maximum and minimum values of the mutual information between the received symbols after cyclic shifting and the standard codewords to make the proposed scheme more robust. We numerically simulated the proposed scheme in a wavelength division multiplexing system, where its channels carry 12.5 Gbaud 4/16/64 QAM and 8/16 PSK. The simulation results show that the modulation format information in the sideband has little effect on the main band information. In the absence of symbol calibration, the receiver can still recover modulation format information from the sideband information with a high accuracy rate. Compared with the MFI algorithm based on Stokes space and the MFI based on signal amplitude performance, the proposed MFI still performs well at low OSNR, although it occupies some bandwidth resources. Moreover, this solution only requires a small number of symbols for decision, so it can achieve fast response requiring little extra storage space.
KW - modulation format recognition
KW - optical communication
KW - orthogonal code
KW - wavelength division multiplexing
UR - http://www.scopus.com/inward/record.url?scp=85078325649&partnerID=8YFLogxK
U2 - 10.1117/12.2548185
DO - 10.1117/12.2548185
M3 - Conference contribution
AN - SCOPUS:85078325649
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Eleventh International Conference on Information Optics and Photonics, CIOP 2019
A2 - Wang, Hannan
PB - SPIE
T2 - 11th International Conference on Information Optics and Photonics, CIOP 2019
Y2 - 6 August 2019 through 9 August 2019
ER -