摘要:
A method includes producing interference between a received optical OFDM signal and an optical carrier extracted from the received optical OFDM signal to provide optical coherent detection of the received optical OFDM signal. Preferably, producing the interference includes optically splitting the received optical OFDM signal into a first part that is filtered to extract the carrier from the received optical OFDM signal and a second part similar to the received optical OFDM signal.
摘要:
A method includes generating at least two lightwave carriers from a lightwave source, the carriers having a wavelength spacing, creating an up-subchannel and a down-subchannel orthogonal to one another and spaced apart based on the fixed wavelength spacing from modulations of the lightwave carriers according to respective up-converted OFDM signals that are carrier suppressed, and combining one lightwave from the up-subchannel and one lightwave from the down-subchannel into an optical channel for transmission over an optical fiber.
摘要:
A method includes producing interference between a received optical OFDM signal and an optical carrier extracted from the received optical OFDM signal to provide optical coherent detection of the received optical OFDM signal. Preferably, producing the interference includes optically splitting the received optical OFDM signal into a first part that is filtered to extract the carrier from the received optical OFDM signal and a second part similar to the received optical OFDM signal.
摘要:
A method includes generating an optical millimeter wave signal for modulation of a first data signal, and deriving from the generated optical millimeter wave signal a subsequent light source for modulation of a second data signal. More specifically the generating includes modulating a light wave to a multiple of a frequency of an oscillating signal. Alternatively, the generating includes modulating a data signal mixed with an oscillating signal to a multiple of a frequency of the oscillating signal. The deriving includes modulating a frequency component filtered from a data modulation of the generated optical millimeter wave signal.
摘要:
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.
摘要:
A method includes generating at least two lightwave carriers from a lightwave source, the carriers having a wavelength spacing, creating an up-subchannel and a down-subchannel orthogonal to one another and spaced apart based on the fixed wavelength spacing from modulations of the lightwave carriers according to respective up-converted OFDM signals that are carrier suppressed, and combining one lightwave from the up-subchannel and one lightwave from the down-subchannel into an optical channel for transmission over an optical fiber.
摘要:
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.
摘要:
Methods and systems for secure communication include assigning data streams to respective orthogonal sub-carriers according to random number information at a transmitter. The data streams are modulated onto the respective orthogonal sub-carriers before the orthogonal sub-carriers are transmitted. The random number information is transmitted on a second medium, separate from the transmission medium. The orthogonal sub-carriers are received from the transmission medium at a receiver, while the random number information is received from the second medium at the receiver. The orthogonal sub-carriers are associated with data streams using the random number information and demodulated to produce data for the associated data stream.
摘要:
An optical apparatus includes a quadrature phase shift keying modulator for generating a non-return-to-zero quadrature phase shift keyed NRZ-QPSK signal from a received lightwave, the modulator being driven by a radio frequency RF signal, an intensity modulator for carving the NRZ-QPSK signal to return-to-zero RZ pulses with a different duty cycle than that of the NRZ-QPSK, the intensity modulator being driven by a radio frequency RF clock signal to change the NRZ-QPSK to an RZ-QPSK signal, and an optical filter with a narrow band for filtering the signal from the intensity modulator to increase optical power that is useable by an optical digital coherent detection system.
摘要:
A passive optical network (PON) device, system and method include an optical line terminal (OLT) receiver configured to receive multiple signals at different wavelengths simultaneously and enable multiple transmitters to operate at the same time during one upstream time slot. The optical line terminal employs Orthogonal Frequency Division Multiple Access (OFDMA) to transparently support a plurality of applications and enable dynamic bandwidth allocation among these applications where the bandwidth is allocated in two dimensional frequency and time space.