The invention discloses an optical transmission device based on direct-sequence-spread-spectrum time-division-multiple-access, which includes a signal transmitting module and a signal receiving module. The transmitting module is connected with the receiving module by optical fibers. The transmitting module is used for receiving an external data sequence signal, encoding the external data sequence signal into a direct-sequence-spread-spectrum time-division-multiple-access electric signal and modulating the resulting electric signal into corresponding spread-spectrum optical signal for transmission by optical fibre. The receiving module is used for receiving the direct-sequence-spread-spectrum time-division-multiple-access optical signal, and sequentially performing photoelectric conversion, analog despreading, analog-digital conversion and clock recovery to obtain the external data sequence signal. The invention realizes direct-sequence-spread-spectrum modulation supporting direct detection; at a receiving end, the despreading in analog domain removes impairments and improves sensitivity. The interleaved configuration of the up-link and down-link chip sequences and dynamic ranging through the time-division-multiple-access protocol realize the interleaved transmission of bytes.

Disclosed are a data transmission device for modulating the amplitude of a PAM-4 signal using a toggle serializer and a method of operating the same. In accordance with an embodiment of the present disclosure, the data transmission device includes a toggle serializer configured to generate at least one toggle signal by detecting logic level change of first and second signals from a Pulse Amplitude Modulation (PAM) signal including the first and second signals; and a driver configured to modulate an amplitude of the PAM signal by combining the first signal, the second signal, and the at least one toggle signal.

This invention relates to a transmitter and transmission system for optical communication that comprises multiplexing of light sources with serial emission of data and protocol negotiation signals to enable binary pulse modulation with miniaturized components. Mounting two different light sources (e.g., VCSELs) antiparallel enables multiplexing functionality while requiring only a two-electrodes package without further inclusion of Zener diodes, resulting in miniaturization and cost reduction.

Duo-binary encoding is used for encoding I and Q data prior to performing orthogonal frequency division multiplexing based transmission using discrete Fourier transform spreading (DFT-S). Advantageously, duo-binary encoding improves robustness of the encoded signal to inter symbol interference, making the degradation caused by the subsequent DFT-S stage less susceptible to reduction in bit error rate performance.

A receiver circuit is disclosed and is configured to receive an optical signal. The receiver circuit includes a receiving circuit configured to receive the optical signal and convert the optical signal from a duobinary signal format into a binary signal based on a plurality of decision thresholds. The receiver circuit also includes a clock data recovery circuit configured to sample the binary signal per data period at a first time instant based on a predetermined clock data recovery technique, and sample the binary signal per data period at a second time instant offset from the first instant, as well as determine an intermediate sample based on an offset for decoding a transmitted bit sequence according to soft information based on the samples.

A receiver circuit is disclosed and is configured to receive an optical signal. The receiver circuit includes a receiving circuit configured to receive the optical signal and convert the optical signal from a duobinary signal format into a binary signal based on a plurality of decision thresholds. The receiver circuit also includes a clock data recovery circuit configured to sample the binary signal per data period at a first time instant based on a predetermined clock data recovery technique, and sample the binary signal per data period at a second time instant offset from the first instant, as well as determine an intermediate sample based on an offset for decoding a transmitted bit sequence according to soft information based on the samples.