Abstract: A wireless optical transceiver, comprising: a light splitter for splitting light emitted from a light source into two lights; a data converter for dividing input data into a plurality of divided data in a symbol unit of a predetermined number of bits, and for converting values of a phase bit and a duty bit at a predetermined position in each of the divided data into a phase control signal and a blocking control signal; a modulator for polarization phase modulating two lights split according to the phase control signal, and for conveying or blocking two modulated polarized lights in response to the blocking control signal to modulate a pulse position; a polarized light combiner for generating a transmission optical signal by combining two polarized lights with a modulated polarization phase and a modulated pulse position; and a light amplifier for amplifying the transmission optical signal and transmitting it through a standby channel.

Abstract: A wireless optical transceiver, comprising: a light splitter for splitting light emitted from a light source into two lights; a data converter for dividing input data into a plurality of divided data in a symbol unit of a predetermined number of bits, and for converting values of a phase bit and a duty bit at a predetermined position in each of the divided data into a phase control signal and a blocking control signal; a modulator for polarization phase modulating two lights split according to the phase control signal, and for conveying or blocking two modulated polarized lights in response to the blocking control signal to modulate a pulse position; a polarized light combiner for generating a transmission optical signal by combining two polarized lights with a modulated polarization phase and a modulated pulse position; and a light amplifier for amplifying the transmission optical signal and transmitting it through a standby channel.

Abstract: Disclosed are a communication method of dynamically allocating subbands in a time-variant channel and a device therefor. In particular, the communication device using dynamically allocated subbands in a time-variant channel includes a subband allocation mode selection unit that selects any one of subband allocation modes based on a communication requirement; a channel estimation unit that performs channel estimation on a plurality of subbands based on the currently selected subband allocation mode; and a control unit that transmits channel estimation information on the subbands to a subband allocation device and is allocated at least one subband satisfying the communication requirement from the subband allocation device.

Abstract: Provided is an apparatus and method for in-phase (I)/quadrature (Q) separated dual multicarrier transmission in a coherent optical transmission system. A multicarrier transmission apparatus includes a carrier generator configured to generate a plurality of multicarrier signals; and a modulator configured to independently modulate input data with respect to an I component and a Q component of an optical carrier using the generated plurality of multicarrier signals.

Abstract: A receiver device and receiving method for a coherent optical communication system are disclosed. The disclosed device includes: an optical splitter configured to split a received optical signal into at least two paths; a first amplifier configured to amplify a second optical signal from among a first optical signal and the second optical signal split into two paths; a second amplifier configured to amplify the output signal of the first amplifier; and a coherent receiver module configured to mix and detect the output signal of the second amplifier and the first optical signal. The disclosed device provides the advantages of suppressing the occurrence of frequency offsets and minimizing phase noise, as well as allowing manufacture with a low cost without requiring either an additional optical source or additional optical fibers.

Abstract: The present invention discloses an apparatus and method for cancelling interference noise in an optical communication system. According to an embodiment of the present invention, an apparatus for cancelling interference noise in an optical communication system in accordance with an embodiment of the present invention comprising: a communication unit for receiving first signals including baseband signals and radio frequency tone signals from at least two subscriber terminals and for detecting a second signal in which the first signals are combined; and a control unit for extracting a first interference noise generated around the radio frequency tone signals from the second signal and for cancelling a second interference noise generated around baseband signals using the first interference noise from the second signal.

Abstract: The present invention discloses an apparatus and method for cancelling interference noise in an optical communication system. According to an embodiment of the present invention, an apparatus for cancelling interference noise in an optical communication system in accordance with an embodiment of the present invention comprising: a communication unit for receiving first signals including baseband signals and radio frequency tone signals from at least two subscriber terminals and for detecting a second signal in which the first signals are combined; and a control unit for extracting a first interference noise generated around the radio frequency tone signals from the second signal and for cancelling a second interference noise generated around baseband signals using the first interference noise from the second signal.

Abstract: Disclosed are an optical network unit included in an OFDMA-PON system that is capable of reducing OBI (optical beat interference), and a method of controlling the optical network unit. The disclosed optical network unit includes: a signal generator part configured to generate an electrical signal carrying transmission data; an RF tone generator part configured to generate an RF tone; a combiner part configured to combine the electrical signal and the RF tone; and a photoelectric converter part configured to convert the combined signal of the electrical signal and RF tone into an optical signal.

Abstract: Provided is an apparatus and method for in-phase (I)/quadrature (Q) separated dual multicarrier transmission in a coherent optical transmission system. A multicarrier transmission apparatus includes a carrier generator configured to generate a plurality of multicarrier signals; and a modulator configured to independently modulate input data with respect to an I component and a Q component of an optical carrier using the generated plurality of multicarrier signals.

Abstract: Disclosed are a communication method of dynamically allocating subbands in a time-variant channel and a device therefor. In particular, the communication device using dynamically allocated subbands in a time-variant channel includes a subband allocation mode selection unit that selects any one of subband allocation modes based on a communication requirement; a channel estimation unit that performs channel estimation on a plurality of subbands based on the currently selected subband allocation mode; and a control unit that transmits channel estimation information on the subbands to a subband allocation device and is allocated at least one subband satisfying the communication requirement from the subband allocation device.

Abstract: A receiver device and receiving method for a coherent optical communication system are disclosed. The disclosed device includes: an optical splitter configured to split a received optical signal into at least two paths; a first amplifier configured to amplify a second optical signal from among a first optical signal and the second optical signal split into two paths; a second amplifier configured to amplify the output signal of the first amplifier; and a coherent receiver module configured to mix and detect the output signal of the second amplifier and the first optical signal. The disclosed device provides the advantages of suppressing the occurrence of frequency offsets and minimizing phase noise, as well as allowing manufacture with a low cost without requiring either an additional optical source or additional optical fibers.

Abstract: Disclosed are an optical network unit included in an OFDMA-PON system that is capable of reducing OBI (optical beat interference), and a method of controlling the optical network unit. The disclosed optical network unit includes: a signal generator part configured to generate an electrical signal carrying transmission data; an RF tone generator part configured to generate an RF tone; a combiner part configured to combine the electrical signal and the RF tone; and a photoelectric converter part configured to convert the combined signal of the electrical signal and RF tone into an optical signal.

Abstract: Disclosed is an apparatus in a diversity system of a mobile terminal having a main receiving unit and a sub-receiving unit, which includes a sub-antenna for receiving an input signal and a part of a transmitted signal of a transmitting unit, a band-pass filter (BPF) designed to greatly attenuate a low-band frequency of the part of the transmitted signal received through the sub-antenna, a high-pass filter (HPF) for additionally attenuating the part of the transmitted signal attenuated through the BPF, a low-noise amplifier for minimizing a noise of an output value of the HPF, an HPF for passing therethrough only a high-frequency component of an output value of the low-noise amplifier, and a mixer for mixing output values of the HPF and outputting a baseband signal. One of two BPFs in the sub-receiving unit is replaced by one HPF, and thus the HPF can be fabricated on chip with the terminal receiving unit.

Abstract: A phase optimization apparatus and method to obtain a maximum extinction ratio by feeding back a portion of an optical signal output from a Mach-Zehnder interferometer wavelength converter using XPM of a semiconductor optical amplifier to maintain an optimum phase difference between two arms. The phase optimization apparatus includes a first arm having a first semiconductor optical amplifier that amplifies a pump signal and a probe signal, a second arm having a second semiconductor optical amplifier that amplifies the probe signal, and a ? phase shifter that controls the phase of the amplified signal, an optical band-pass filter that filters optical signals to output only the modulated probe signal; and a phase control unit that receives feedback to output to the ? phase shifter of the second arm a phase control signal, which controls a phase difference between the first and second arms.

Abstract: An optical logic element includes a first interferometer modulating a continuous optical signal in response to first and second optical signals to output a first modulation signal, and a second interferometer modulating the continuous optical signal in response to a sum signal equal to the sum of the first and second optical signals to output a second modulation signal. The first and second modulation signals and the sum signal are respectively the results of predetermined logic operations performed on the first and second optical signals.

Abstract: A method and apparatus for controlling an optical gain difference and an optical phase difference in a semiconductor optical amplifier—Mach-Zehnder interferometer (SOA-MZI) wavelength converter having two arms and that outputs probe output signals POH and POL, corresponding to pump input signals of logic high and logic low, respectively. The controlling includes detecting an optical power level of the output probe signals and controlling at least one of an optical gain difference between the two arms and an optical phase difference between the two arms in accordance with a detected optical power level of the probe output signal.

Abstract: A method and apparatus for controlling an optical gain difference and an optical phase difference in a semiconductor optical amplifier-Mach-Zehnder interferometer (SOA-MZI) wavelength converter having two arms and that outputs probe output signals POH and POL, corresponding to pump input signals of logic high and logic low, respectively. The controlling includes detecting an optical power level of the output probe signals and controlling at least one of an optical gain difference between the two arms and an optical phase difference between the two arms in accordance with a detected optical power level of the probe output signal.

Abstract: Disclosed is an apparatus in a diversity system of a mobile terminal having a main receiving unit and a sub-receiving unit, which includes a sub-antenna for receiving an input signal and a part of a transmitted signal of a transmitting unit, a band-pass filter (BPF) designed to greatly attenuate a low-band frequency of the part of the transmitted signal received through the sub-antenna, a high-pass filter (HPF) for additionally attenuating the part of the transmitted signal attenuated through the BPF, a low-noise amplifier for minimizing a noise of an output value of the HPF, an HPF for passing therethrough only a high-frequency component of an output value of the low-noise amplifier, and a mixer for mixing output values of the HPF and outputting a baseband signal. One of two BPFs in the sub-receiving unit is replaced by one HPF, and thus the HPF can be fabricated on chip with the terminal receiving unit.