Abstract
The proposed work depicts a Nyquist-wavelength division multiplexing (Nyquist-WDM) superchannel, which consists of five subcarriers based on advanced modulation format, i.e., polarization multiplexed-8 quadrature amplitude modulation (PM-8QAM) format. The proposed model delivers excellent transmission capacity of 832.5 Gb/s (i.e., 5 × 166.5 Gb/s) at baud rate 27.75 Gb/s with 11% forward error correction (FEC) overhead. Bandwidth of each Nyquist filter at transmitter end is kept 33.33 GHz (i.e., 1.2 × baud rate). At this 33.33 GHz bandwidth, all five subcarriers are aggregated for the sake of giving birth to a bandwidth-efficient superchannel with 5b/s/Hz spectral efficiency. Few key optical performance parameters are optical signal to noise ratio (OSNR), laser input power level, bit error rate (BER) and optical spectrum of the superchannel. At reference BER of value 4 × 10−3, a performance comparison is also presented among different higher-order polarization multiplexed formats, which reflects that to achieve same BER, more OSNR is required by higher-order modulation formats. The proposed concept is applicable in terrestrial communication and flexible optical networks.
