Abstract: An optical line terminal transmitter front-end, an optical network terminal receiver front-end and a bit-interleaved passive optical network (BIPON). In one embodiment, the transmitter front-end includes: (1) a bit interleaver configured to group and interleave a plurality of user bit-streams to yield a combined single bit-stream, (2) an encoder coupled to the bit interleaver and configured to encode multiple bits of the single bit-stream into a multi-level code corresponding to a 2m-level multi-level signal and (3) a multi-level modulator coupled to the encoder and configured to modulate the multi-level code into the 2m-level multi-level signal.

Abstract: An optical line terminal transmitter front-end, an optical network terminal receiver front-end and a bit-interleaved passive optical network (BIPON). In one embodiment, the transmitter front-end includes: (1) a bit interleaver configured to group and interleave a plurality of user bit-streams to yield a combined single bit-stream, (2) an encoder coupled to the bit interleaver and configured to encode multiple bits of the single bit-stream into a multi-level code corresponding to a 2m-level multi-level signal and (3) a multi-level modulator coupled to the encoder and configured to modulate the multi-level code into the 2m-level multi-level signal.

Abstract: A method and apparatus for processing a communication signal in an optical network. A network node typically includes a transmit train for generating transmissions and a receive train for receiving transmissions from another network node. The network node may be, for example, an OLT or an ONU. In a receiver implementing the described solution, a photodiode is employed to convert received optical signals into electrical signals that are then provided to a TIA or other device for producing a differential output having an inverted output and a non-inverted output. One of the outputs is delayed one bit and attenuated, then combined with the other output to produce an equalized signal for further processing by the receive train. The solution may be analogously applied on the transmit side for introducing pre-distortion, either in addition to or in lieu of in the receiver.

Abstract: Introduced herein is an optical network device employing three-level duobinary modulation and a method of use thereof. One embodiment of an optical network receiver module includes: (1) an optical input configured to receive an optical non-return-to-zero (NRZ) signal having a data rate, and (2) an encoder having a maximum bandwidth, coupled to the optical input and configured to receive and encode the optical NRZ signal into an electrical three-level duobinary signal, the maximum bandwidth being related to, but substantially less than, the data rate.

Abstract: An optical receiver that uses a coherent optical quadrature-detection scheme to demodulate an amplitude-modulated optical input signal in a manner that enables the use of a free-running optical local-oscillator source. The optical receiver employs a signal combiner that combines, into an electrical output signal, the in-phase and quadrature-phase electrical signals generated as a result of the quadrature detection of the optical input signal. Depending on the frequency offset between the local-oscillator signal and the input signal, the electrical output signal produced by the signal combiner can be a desired baseband signal or an intermediate-frequency signal. The latter signal can be demodulated to recover the baseband signal in a relatively straightforward manner, e.g., using a conventional intermediate-frequency electrical demodulator coupled to the signal combiner.