Telecom network equipment vendor ZTE today said it has demonstrated real-time transport and coherent detection of 100G orthogonal frequency division multiplexing (OFDM) signal.
The Chinese telecom vendor claimed that it transmitted the signal over a long distance in standard single mode fiber without optical dispersion compensation.
ZTE said the world’s first coherent detection of an OFDM optical signal will lay the foundation for the long-distance transmission and coherent detection of OFDM signals.
Compared to an offline coherent optical OFDM transmission system, a real-time coherent detection of OFDM transmission system resolves the problems of limited hardware resources and improves signal precision, said ZTE.
During the demonstration, ZTE used time-domain synchronization and a frequency offset estimation algorithm. This algorithm optimizes complex floating-point multiplication into a simple sign shift operation by only comparing the signature of the signal.
ZTE said the high power peak-to-average ratio in the OFDM signal transmission was reduced using distortion reduction technology, and the moving average of frequencies was used to estimate channel demand to eliminate the noise in the fiber channel and thus reduce errors in the system’s performance.
In March 2014, the Shenzhen-based ZTE became the first telecom network vendor to realize dual-carrier real-time 100Gbps transmission direct detection for a 16QAM-OFDM signal and to implement the transmission of the signal.
