Multiple Channel Interference Cancellation of Digital Filter Multiple Access PONs

Experimental demonstrations of 30Gb/s/λ digital orthogonal filtering-multiplexed multiple channel transmissions over IMDD PON systems utilizing 10G-class optical devices

“…The channel roll-off effect introduces amplitude variations between the corresponding frequency components in the upper and lower sidebands, this prevents full cancellation between the sidebands of the unwanted signal when these sidebands are mapped back in the receiver. As such, the crosschannel interference (CCI) effect occurs [14,15]. In particular, a larger system frequency response roll-off causes a greater amplitude variation between the two sidebands, thus lower frequency subcarriers suffer more CCI, leading to the utilization of low signal modulation formats on these subcarriers to obtain the acceptable bit error rate (BER) performances, as observed in Figs.…”

“…On the other hand, to improve the software-controllable network reconfigurability and network bandwidth utilization efficiency, by making use of digital orthogonal filtering (DOF) implemented with hardware-based digital signal processing (DSP), we have recently proposed and theoretically investigated a novel channel multiplexing/demultiplexing technique [12], in which centralized SDN controller-managed, software-reconfigurable digital orthogonal filters are embedded in transceivers to adaptively and dynamically combine and separate different digital signal channels according to channel spectral characteristics and network traffic status. It has been shown [12][13][14][15] that the proposed DOF-based multiplexing/demultiplexing technique not only provides the PON systems with the aforementioned online network operation functionalities, but also has the excellent potential of achieving the integrated cloud access networks, because of its salient advantages listed below:…”

Performance Tolerance of IMDD DFMA PONs to Channel Frequency Response Roll-Off

“…To effectively mitigate the channel frequency response-induced CCI, a DSP-based CCI cancellation (CCIC) technique has been proposed and experimentally demonstrated in a point-to-point IMDD DFMA PON system [6]. Also a more comprehensive DSP-based DFMA channel interference cancellation (DCIC) technique has been numerically investigated in multipoint-to-point IMDD DFMA PONs [7].…”

“…Here we focus on upstream PON performance as this is subject to more variations in its operating conditions, resulting from the independently operating ONUs. Furthermore, a two ONU PON is considered sufficient for the analysis as roll-off induced CCI is only dependent on roll-off within orthogonal sub-bands [7].…”

“…The optical signal extinction ratio (ER) [9] in each ONU is finely adjusted to ensure good agreement between numerical simulations and experimental measurements for all different scenarios. The introduction of the LPF profiles and suitable signal ERs allows the utilization of an ideal intensity modulator in each ONU [7]. As a direct result, the intensity modulation-induced frequency chirp is also negligible.…”