Abstract:
A receiver and method are provided for mitigation of finer non-linearities in multilevel coded-modulation schemes. The receiver includes a multilevel Bahl-Cocke-Jelinek-Raviv (BCJR) equalizer configured to receive channel samples of an input signal, partially mitigate fiber non-linearities, and provide symbol reliabilities. The receiver further includes a bit probabilities module coupled to the BCJR equalizer configured to calculate soft bit reliabilities from the symbol reliabilities. The receiver also includes one or more low-density parity-check (LDPC) decoders coupled to the bit probabilities module and the BCJR equalizer, configured to receive the soft bit reliabilities and output code words. The one or more LDPC decoders iteratively provide extrinsic soft information feedback to the BCJR equalizer to compensate for the fiber non-linearities.
Abstract:
A receiver and method are provided. The receiver includes a detector configured to receive polarization multiplexed coded orthogonal frequency division multiplexing input sequences and generate estimates of unknown transmitted symbols in the input sequences for x- and y-polarization channels with respect to laser phase noise and PMD. A demapper coupled to the detector is configured to partially cancel polarization mode dispersion (PMD) in the input sequences by computing symbol probabilities for the estimates with respect to the laser phase noise, and averaging the symbol probabilities with respect to the laser phase noise. One or more low-density parity-check (LDPC) decoders coupled to the demapper are configured to receive bit probabilities derived from the averaged symbol probabilities and output code words based at least on the bit probabilities. The one or more LDPC decoders iteratively provide extrinsic soft information feedback to the demapper to compensate for the PMD.
Abstract:
There is provided a method for detecting optical signals comprising employing a photo diode to both directly detect a received optical signal and convert it into an electrical signal for recovery of data bit stream information in the received optical signal, the received optical signal being derived from a separation of two polarization multiplexed optical signals that were combined before being received.
Abstract:
Systems and methods are disclosed for dynamic channel estimation in a digital receiver by performing a dynamic equalization on an incoming signal to compensate for channel distortion; independently estimating one or more channel parameters for the dynamic equalization, wherein the one or more channel parameters track channel change; determining a convolution of the channel parameters and updating the parameters for the dynamic equalization for subsequent processing of incoming signal; and providing an equalized output from the digital receiver.
Abstract:
Systems and methods are disclosed for providing media access control (MAC) in an optical network by providing a separate control channel and data channel; dedicating each optical network unit (ONU) with one control channel, wherein the control message is transmitted at any time without constraints; sending a grant message to an ONU just before an allocated time is about to start; and sending data traffic from the ONU immediately after receiving the grant message without synchronizing with an optical line terminal (OLT) clock.
Abstract:
Methods and systems for controlling power fluctuations in a network including a plurality of nodes are disclosed. A node in the network may be configured to modify power levels in accordance with either an active state or an inactive state. The node may transition to an inactive state in response to a power change that exceeds a power change threshold. The role of the node in controlling the power fluctuation in the network is reduced in the inactive state.
Abstract:
A source synchronous signal synchronization system includes a differential signal receiver; a tunable input delay element coupled to the receiver; an input serializer/deserializer (ISerDes) coupled to the tunable input delay; an alignment unit coupled to the ISerDes; and a delay control unit coupled to the tunable input delay, the ISerDes, and the alignment unit.
Abstract:
A bale of elastomer composite is formed of elastomer and filler, the bale having a void volume of at least 3%. In another aspect, a container is provided, at least a portion of the container being occupied by elastomer composite pieces of elastomer and filler, wherein the occupied portion of the container has a void volume of at least 3%.
Abstract:
Implementations of the present principles include methods, systems and apparatuses for transmitting data through a sub-carrier multiplexing and orthogonal frequency-division multiple access passive optical network. In accordance with aspects of the present principles, a plurality of optical network units are assigned electrical carrier frequency bandwidths that are narrower than a system capacity bandwidth. Modulation of optical waves transmitted between an optical line terminal and each optical network unit is conducted on different orthogonal sub-carrier frequencies within the assigned bandwidths such that sampling of said orthogonal sub-carrier frequencies is limited to the assigned electrical carrier frequency bandwidths. The waves are thereafter received and demodulated for the extraction of data.
Abstract:
A tunable asymmetric interleaver constructed from two symmetric interleavers in series, wherein either or both of the individual symmetric interleavers exhibit a wavelength shifting ability. Advantageously, tunable asymmetric interleavers so constructed provide continuous tunable interleaving ratios from 0:100 to 50:50 to 100:0 and provide attractive upgrade paths for existing and future DWDM networks and applications.