Class / Patent application number | Description | Number of patent applications / Date published |
398203000 | Homodyne | 11 |
20080267637 | Method & Apparatus for Demodulating an Optical Differential Phase-Shift Keying Signal - Demodulating an optical Differential Phase-Shift Keying (DPSK) signal is accomplished using a self-homodyne receiver for receiving the optical signal. A converter converts the optical signal received by the self-homodyne receiver into a representative electrical signal. A processor that processes the representative electrical signal using decision feedback multi-symbol detection in order to obtain a decision variable that indicates a differential phase-shift in the optical signal. | 10-30-2008 |
20090047029 | Waveform Shaping Apparatus, Receiver, Reception Module, and Remote Control Receiver - A waveform shaping apparatus has a first integrating circuit | 02-19-2009 |
20100098438 | HOMODYNE RECEIVER FOR OPTICAL COMMUNICATIONS WITH POST PROCESSING - The receiver comprises a first optical fibre input element ( | 04-22-2010 |
20100296821 | RECEIVING APPARATUS AND METHOD FOR ELECTRONIC NOISE COMPENSATION IN PHASE MODULATED OPTICAL TRANSMISSION - A receiving apparatus and method for processing a differential phase shift keying signal carrying a plurality of symbols are disclosed to provide for improved compensation of linear and non-linear noise in phase modulated optical transmission. The receiving apparatus comprises an input unit for receiving electrical signals derived from an optical signal and a calculation unit for calculating a current value of a decision variable. The current value is indicative of a differential phase shift in the optical signal between a currently received symbol and a previously received symbol as a function of the optical signal power of the optical signal for the currently received symbol and at least one previous value of the decision variable. The receiving apparatus also comprises a decision unit for determining the differential phase shift from the current value of the decision variable obtained from the calculation unit to obtain the currently received symbol. | 11-25-2010 |
20110008061 | Synchronous circuit for use in optical homodyne receiver for generating local oscillation light with accurate demodulation - In a synchronous circuit, a synchronizing signal generator combines either an optical BPSK signal or local oscillation light with a phase-shifted signal to produce different optical signals, one of which for use in producing a signal demodulated from the BPSK signal is square-law detected, and calculates the optical signal detected to convert the signal into an electric signal. The generator produces an electric phase-locking signal which will be a demodulated signal from the BPSK signal on the basis of the electric signal. The phase-locking signal is used as a modulating signal by an intensity-modulating circuit to modulate an incident continuous light into an optical intensity-modulated signal, which is optoelectrically converted and square-law detected by an optoelectric converter. The converted signal is used by an optical VCO circuit as a phase error signal to adjust the phase or frequency of the local oscillation light, which is supplied to the signal generator. | 01-13-2011 |
20110150504 | COHERENT OPTICAL RECEIVER SYSTEM AND METHOD FOR DETECTING PHASE MODULATED SIGNALS - One aspect of the invention is a homodyne coherent receiver, suitable for high speed phase shift keying (PSK), the receiver comprising a receiver for receiving an incoming signal having a carrier-less modulation format, a signal conditioning sub-system that generates a carrier component from the incoming signal, and an optical injection phase locked loop (OIPLL) that phase locks the generated carrier component of the incoming signal. Embodiments of the invention may enable DSP free detection of optical PSK signals, which may be required in next generation fiber transmission systems and in optical constellation analyzer systems. In addition, embodiments of the invention may provide improved receiver sensitivity performance comparing to prior art systems using direct detection schemes. Also, embodiments of the invention may be advantageous in terms of cost and energy efficiency. | 06-23-2011 |
20110222867 | Optical Receiver Using Single Ended Voltage Offset Measurement - An optical receiver includes an optical detector that generates a photocurrent at an output. A transimpedance amplifier generates an amplified voltage signal corresponding to the photocurrent generated by the optical detector. An offset voltage generator generates an offset voltage that biases the voltage signal generated by the transimpedance amplifier. A switch having a first input electrically connected to the output of the transimpedance amplifier and a second input electrically connected to the output of the offset voltage generator switches between the offset voltage and the voltage signal generated by the transimpedance amplifier. | 09-15-2011 |
20110262150 | HIGH-SPEED PULSED HOMODYNE DETECTOR IN TELECOM BAND - [Object] It is to raise operational frequency and S/N ratio of the pulsed homodyne detector to measure the quadrature amplitude of the signal pulse light. | 10-27-2011 |
20140093254 | VISIBLE LIGHT RECEIVING DEVICE AND VISIBLE LIGHT RECEIVING METHOD - A receiving device includes a first conversion unit, an amplification unit, and a microcomputer. The microcomputer includes: a second conversion unit that performs, for each sampling time duration, AD conversion on a voltage signal into an AD-converted value; a first calculation unit that calculates a difference digital value by difference calculation; a second calculation unit that calculates a positive reference value and a negative reference value; a detection unit that detects a rising point starting difference digital values greater than the positive reference value, and a falling point starting difference digital values smaller than the negative reference value; a third calculation unit that calculates a first sample period and a second sample period; and a fourth calculation unit that calculates a modulated signal for each symbol time period based on the first sample period and the second sample period. | 04-03-2014 |
20140341594 | Optical Homodyne Coherent Receiver and Method For Receiving a Multichannel Optical Signal - This disclosure relates to an optical receiver arrangement ( | 11-20-2014 |
20150050032 | DIGITALLY LOCKING COHERENT RECEIVER AND METHOD OF USE THEREOF - A digitally locking coherent receiver and a method of coherently receiving a data signal. One embodiment of the receiver includes: (1) a detector configured to recover a composite signal with respect to a local oscillator signal, the composite signal being a combination of a data signal and a reference signal, and (2) a digital signal processor (DSP) communicably coupled to the detector and configured to recognize and compensate for drift in the local oscillator signal with respect to the reference signal. | 02-19-2015 |