Patent application number | Description | Published |
20080225380 | Delay line interferometer having a movable mirror - An optical receiver apparatus and methods for mitigating intersymbol interference (ISI) in a differentially-encoded modulation transmission system by controlling constructive and destructive transfer functions. The receiver includes a bandwidth control element for controlling transfer function bandwidth, a transfer phase controller for controlling transfer function phase and/or an imbalancer for imbalancing the transfer functions for compensating for intersymbol interference and optimizing the quality of the received optical signal. | 09-18-2008 |
20080225381 | Delay line interferometer having a stepped delay element - An optical receiver apparatus and methods for mitigating intersymbol interference (ISI) in a differentially-encoded modulation transmission system by controlling constructive and destructive transfer functions. The receiver includes a bandwidth control element for controlling transfer function bandwidth, a transfer phase controller for controlling transfer function phase and/or an imbalancer for imbalancing the transfer functions for compensating for intersymbol interference and optimizing the quality of the received optical signal. | 09-18-2008 |
20080226306 | GT decoder having bandwidth control for ISI compensation - An optical receiver apparatus and methods for mitigating intersymbol interference (ISI) in a differentially-encoded modulation transmission system by controlling constructive and destructive transfer functions. The receiver includes a bandwidth control element for controlling transfer function bandwidth, a transfer phase controller for controlling transfer function phase and/or an imbalancer for imbalancing the transfer functions for compensating for intersymbol interference and optimizing the quality of the received optical signal. | 09-18-2008 |
20080232821 | Optical receiver having transfer function bandwidth selection - An optical receiver apparatus and methods for mitigating intersymbol interference (ISI) in a differentially-encoded modulation transmission system by controlling constructive and destructive transfer functions. The receiver includes a bandwidth control element for controlling transfer function bandwidth, a transfer phase controller for controlling transfer function phase and/or an imbalancer for imbalancing the transfer functions for compensating for intersymbol interference and optimizing the quality of the received optical signal. | 09-25-2008 |
20090116851 | Optical Receiver Having Bandwidth Control For Intersymbol Interference Compensation - Apparatus and techniques for receiving and processing an optical signal. In one implementation, an optical receiver is provided to include a delay line interferometer, an etalon, and a data estimator for estimating the data carried on a differentially modulated optical input signal. The delay line interferometer receives the input signal and issues differentially decoded constructive and destructive signals. The etalon filters the constructive signal with a transmission stopband imposed over the passband of the constructive signal. The bandwidth of the etalon stopband is selected based on the bandwidth of the modulation of the input signal in order to maximize received signal quality. The data estimator uses a difference between signals derived from the filtered constructive signal and the destructive signal for estimating data. | 05-07-2009 |
20090136240 | Balanced Phase-Shaped Binary Transmission In Optical Communications - Optical communication apparatus, methods, systems are provided based on balanced-detection phase-shaped binary transmission (BD-PSBT). | 05-28-2009 |
20090196602 | Adjustable Bit Rate Optical Transmission Using Programmable Signal Modulation - Techniques, apparatus and systems to provide adjustable bit rate optical transmission using programmable signal modulation in optical communication systems. | 08-06-2009 |
20100284702 | Optical Receivers with Controllable Transfer Function Bandwidth and Gain Imbalance - Techniques, devices and systems based on optical receivers with controllable transfer function bandwidth and gain imbalance. | 11-11-2010 |
20110097092 | Optical Receiver Having Fractional Sampling - Apparatus and methods for receiving and processing optical signals carrying symbols that represent data, including an optical receiver having fractional sampling analog-to-digital conversion and interpolation timing recovery synchronization for processing an optical signal. | 04-28-2011 |
20110236025 | SUB-RATE SAMPLING IN COHERENT OPTICAL RECEIVERS - Apparatus and methods for optimizing the interplay between the sampling rate of an ADC of a receiver system and a bandwidth of analog anti-aliasing filters are described. The described technology can be used to mitigate aliasing for receiver systems that operate at fractional sampling rates by optimizing a bandwidth of optical and electrical filters included in the receiver systems. | 09-29-2011 |
20120106982 | Coherent optical receiver with adaptive equalizer initialization system - An adaptive-equalizer initialization system performs three functions: frequency offset estimation, taps estimation for chromatic dispersion filters, and taps initialization for an adaptive equalizer. The system contains hardware FFT and peak detector units that sense a pure tone that marks the beginning of a known, short data sequence. | 05-03-2012 |
20130259490 | PROCESSING DATA IN A COHERENT OPTICAL COMMUNICATION SYSTEM - This disclosure describes techniques to sample electrical data streams in coherent receivers. For instance, an analog-to-digital converter (ADC) samples the received electrical data stream at a sampling rate that is nominally twice or greater than twice the symbol rate of the electrical data stream that the ADC receives. A digital filter receives the digital data stream from the ADC, and digitally filters the digital data streams to output a filtered digital electrical data stream at an effective sampling rate that is less than the sampling rate and less than twice the symbol rate, and greater than or equal to the symbol rate. | 10-03-2013 |
20140212138 | OPTICAL ACCESS NETWORK HAVING EMITTER-FREE CUSTOMER PREMISE EQUIPMENT AND ADAPTIVE COMMUNICATION SCHEDULING - An access network includes an access device having an optical interface module that outputs a plurality of pairs of optical communication signals, each of the pairs of optical communication signals comprising a modulated optical transmit signal and an unmodulated optical receive signal, each of the pairs of optical communication signals having a different wavelength. A customer premise equipment (CPE) comprises an optical interface module to receive the modulated optical transmit signal and the unmodulated optical receive signal for any of the plurality of pairs of optical communication signals. The optical interface module includes a receive module to demodulate the modulated optical transmit signal into inbound symbols and a transmit module having an optical modulator and reflective optics to modulate the unmodulated optical receive signal in accordance with a data signal and reflect a modulated optical receive signal to communicate outbound data symbols to the access device. | 07-31-2014 |