Coherent spectral amplitude coded label detection for DQPSK payload signals in packet-switched metropolitan area networks

We report on an experimental demonstration of a frequency swept local oscillator-based spectral amplitude coding (SAC) label detection for DQPSK signals after 40 km of fiber transmission. Label detection was performed for a 10.7 Gbaud DQPSK signal labeled with a SAC label composed of four-frequency tones with 500 MHz spectral separation. Successful label detection and recognition is achieved with the aid of digital signal processing that allows for substantial reduction of the complexity of the detection optical front-end.