Applied Micro Circuits Corporation

Keith Michael Conroy

Omer Acikel

Warm Shaw Yuan

Daniel M Castagnozzi

Francesco Caggioni

Alan Michael Sorgi

Subhash Chandra Roy

Igor Zhovnirovsky

Wei Fu

Hongming An

Allen Carl Merrill

A system and method are provided for calibrating orthogonal polarity in a multichannel optical transport network (OTN) receiver. The method accepts a composite signal and separates the polarization of the signal into a pair of 2-phase shift keying (2-PSK) modulated input signals via Ix and Qx optical signal paths, where n&#x2267;1. Likewise, a pair of 2-PSK modulated input signals are accepted via Iy and Qy optical signal paths where p&#x2267;1. Polarization-adjusted I'x, Q&#x2032;x, I&#x2032;y, and Q&#x2032;y signals are generated. An average magnitude is compared to either 2&#xd7; the absolute magnitude of (I&#x2032;x and Q&#x2032;x), or 2&#xd7; the absolute magnitude of (I&#x2032;y and Q&#x2032;y). The average magnitude value can be used that is either 2&#xd7; (a predetermined peak signal amplitude), or the sum of the absolute magnitudes of (I&#x2032;x and Q&#x2032;x) and (I&#x2032;y and Q&#x2032;y). The polarization-adjusted I&#x2032;x, Q&#x2032;x, I&#x2032;y, and Q&#x2032;y signals are modified until the magnitude comparison is about zero.

Multichannel polarization control for polarization multiplexed optical transport networks

Systems and methods are provided for multi-channel ITU G.709 optical transport network (OTN) communications. The transmission method accepts an ITU G.709 OTN frame including an OTU overhead (OH) section and an ODU section. A forward error correction (FEC) parity section with a training signal is appended to the ITU G.709 OTN frame, to create a training-enhanced (TE) OTN frame. All, or a portion of the TE OTN may be buffered in a tangible memory medium in preparation for striping. The training-enhanced OTN frame is then striped into n parallel streams, and n TE_OTN-PFs (Parallel Frames) are supplied.

Multi-channel optical transport network training signal

A Free Space Optics (FSO) connector is provided with a method for interfacing to an electronic circuit card electrical connector via the FSO connector. The method transceives electrical signals via an electronic circuit card electrical connector. Using an FSO connector, the method converts between electrical signals and optical signals, and transceives optical signals via free space. In one aspect, the optical signals are initially received via free space along a first axis, and reflected along a second axis. Further, the optical signals may be initially transmitted along the second axis and reflected into free space along the first axis. In another aspect, the optical signals are transceived in a plurality of directions in free space. For example, optical signals may be transmitted and received in four mutually-orthogonal axes.

Free space optical connector

Systems and methods are provided for multi-channel ITU G.709 optical transport network (OTN) transmission and receiving. The transmission method accepts a canonical ITU G.709 OTN frame including an OTU overhead (OH) section, an ODU section, and a forward error correction (FEC) parity section. A training signal wrapper is added to the ITU G.709 OTN frame, and at least a portion of a training-enhanced (TE) OTN frame is buffered in a tangible memory medium in preparation for striping. The method stripes the training-enhanced OTN frame into n parallel streams to supply n TE_OTN-PFs (Parallel Frames) at an output.

Multi-channel optical transport network training signal wrapper

Fiber optic cable jacks and plugs are provided. In one aspect, a cable is made from at least one length of fiber optic line having a first end and a second end. A first plug includes a one-piece mechanical body with a cable interface to engage the fiber optic line first end, and a microlens to transceive light with the cable interface. The first plug is shaped to engage a first jack housing. A second plug includes a one-piece mechanical body with a cable interface to engage the fiber optic line second end, and a microlens to transceive light with the cable interface. The second plug is shaped to engage a second jack housing. The mechanical bodies have inner walls that form an air gap cavity interposed between the microlens convex surface and an engaging jack optical interface.

Fiber optic cable connector

A system and method are provided for calibrating temporal skew in a multichannel optical transport network (OTN) transmission device. The method accepts a pair of 2-phase shift keying (2-PSK) modulated signals, as well as a pair of 2-PSK modulated signals. The 2-PSK and 2-PSK signals are converted to 2-PSK and 2-PSK optical signals, respectively. The 2-PSK and 2-PSK optical signals are orthogonally polarized and transmitted. A timing voltage is generated that is responsive to the intensity of the orthogonally polarized signals. The timing voltage is correlated to a reference frame calibration pattern associated with a preamble/header portion of an OTN frame. Then, the timing voltages associated with the Ix, Qx, Iy, and Qy signal paths are compared, and the misalignment between the timing voltages and the reference frame calibration pattern is minimized in response to adjusting time delay modules in the Ix, Qx, Iy, and Qy signal paths.

Multichannel optical transport network optical detection skew calibration

A system and method are provided for calibrating skew in a multichannel optical transport network (OTN) transmission device. The method accepts a pair of 2-phase shift keying (2PSK) modulated signals via Ix and Qx electrical signal paths, where n&#x3e;1. Likewise, a pair of 2-PSK modulated signals are accepted via Iy and Qy electrical signal paths where p&#x3e;1. The Ix, Qx, Iy, and Qy signals are correlated to a preamble/header portion of an OTN frame. A voltage on the Ix signal path is compared with Qx, and VOvoltage is generated. A voltage on the Iy signal path is compared with Qy, and VOis generated. One of the Ix or Qx voltages is compared with one of Iy or Qy voltages to generate VOxy. Then, the VO voltages are minimized in response to adjusting time delay modules in the Ix, Qx, Iy, and Qy signals paths.

Multichannel optical transport network skew calibration

A system and method are provided for controlling time delay in a multichannel optical transport network (OTN) transmission device using time domain reflectometry (TDR) measurements. The method accepts a pair of 2-phase shift keying (2-PSK) modulated signals via Ix and Qx electrical signal paths, where n&#x3e;1. Likewise, a pair of 2-PSK modulated signals are accepted via Iy and Qy electrical signal paths where p&#x3e;1. Using TDR modules, signal reflections are measured from an output port for each signal path. The method minimizes time delay differences in the signal reflections for the Ix, Qx, Iy, and Qy signals paths by using the signal reflection measurements to adjust time delay modules in each signal path.

Multichannel optical transport network time domain reflectometry calibration

A system and method are provided for controlling time delay in a multichannel optical transport network transmission device. The method accepts a pair of 2-phase shift keying (2PSK) modulated signals via Ix and Qx electrical signal paths, where n&#x3e;1, and a pair of 2-PSK modulated signals via Iy and Qy electrical signal paths where p&#x3e;1. A voltage Von the Ix signal path is compared with a voltage Von the Qx signal path, and a VOx voltage in generated, which is minimized by adjusting time delay modules in the Ix and Qx signals paths. Likewise, a voltage V(Iy) is compared with a voltage V(Qy), and a VOy voltage is generated and minimized. Subsequent to minimizing VOx and VOy, the sum of Vand V(V) is compared with the sum of Vand V(V), and a VOxy voltage is generated and minimized.

Multichannel optical transport network skew control

A system and method are provided for feed-forward equalization (FFE) in a transmission system. The method accepts a serial stream of input digital data signals. For each input data signal, a temporal sequence of signals is generated. Each of the signals in the temporal sequence is selectively shaped. Shaping map include varying the degree of amplification, modifying the slew rate, or varying the time delay. The contributions of the selectively shaped signals in the temporal sequence are then selectively weighted, and a summed output signal is transmitted.

Current mode logic multi-tap feed-forward equalizer

A system and method are provided for calibrating orthogonal polarity in a multichannel optical transport network (OTN) receiver. The method accepts a composite signal and separates the polarization of the signal into a pair of 2-phase shift keying (2-PSK) modulated input signals via Ix and Qx optical signal paths, where n&#x2267;1. Likewise, a pair of 2-PSK modulated input signals are accepted via Iy and Qy optical signal paths where p&#x2267;1. Polarization-adjusted I'x, Q&#x2032;x, I&#x2032;y, and Q&#x2032;y signals are generated. An average magnitude is compared to either 2&#xd7;the absolute magnitude of (I&#x2032;x and Q&#x2032;x), or 2&#xd7;the absolute magnitude of (I&#x2032;y and Q&#x2032;y). The average magnitude value can be used that is either 2&#xd7;(a predetermined peak signal amplitude), or the sum of the absolute magnitudes of (I&#x2032;x and Q&#x2032;x) and (I&#x2032;y and Q&#x2032;y). The polarization-adjusted I&#x2032;x, Q&#x2032;x, I&#x2032;y, and Q&#x2032;y signals are modified until the magnitude comparison is about zero.

Polarization control for multichannel and polarization multiplexed optical transport networks

A system and method are provided for five-level non-causal channel equalization in a communications system. The method comprises: receiving a non-return to zero (NRZ) data stream input; establishing a five-level threshold; comparing the first bit estimate to a second bit value received prior to the first bit; comparing the first bit estimate to a third bit value received subsequent to the first bit; and, in response to the comparisons, determining the value of the first bit. Establishing a five-level threshold includes: establishing thresholds to distinguish a first bit value when the second and third bit values are a '1' value, when the second bit value is a '1' and the third bit value is a &#x201c;0&#x201d;, when the second bit value is a &#x201c;0&#x201d; and the third bit value is a &#x201c;1&#x201d;, when the second and third bit values are a &#x201c;0&#x201d; value, and an approximate midway threshold.

System for five-level non-causal channel equalization

A modified gain system and method are provided for non-causal channel equalization using feed-forward and feedback compensation. The method comprises: receiving a serial data stream first bit (present) input; comparing a second bit (past) value, received prior to the first bit input, to a third bit (future) value received subsequent to the first bit input; modifying the amplitude of the first bit input to compensate for the effect of the second and third bit values being equal; and, determining the value of the first bit input by comparing the amplitude modified first bit input to a Vopt threshold. When only one of the second and third bit values is a '1' value, a unity amplitude modifier is supplied. When the second and third bit values are a '1', a low amplitude modifier is supplied. When the second and third bit values are a &#x201c;0&#x201d;, a high amplitude modifier is supplied.

Modified gain non-causal channel equalization using feed-forward and feedback compensation

A system and method are provided for five-level non-casual channel equalization in a communications system. The method comprises: receiving a non-return to zero (NRZ) data stream input; establishing a five-level threshold; comparing the first bit estimate to a second bit value received prior to the first bit; comparing the first bit estimate to a third bit value received subsequent to the first bit; and, in response to the comparisons, determining the value of the first bit. Establishing a five-level threshold includes: establishing thresholds to distinguish a first bit value when the second and third bit values are a '1' value, when the second bit value is a '1' and the third bit value is a &#x201c;0&#x201d;, when the second bit value is a &#x201c;0&#x201d; and the third bit value is a &#x201c;1&#x201d;, when the second and third bit values are a &#x201c;0&#x201d; value, and an approximate midway threshold.

System and method for five-level non-causal channel equalization

A system and method are provided for non-causal channel equalization in a communications system. The method comprises: establishing a first threshold (V) to distinguish a high probability '1' first bit estimate; establishing a second threshold (V) to distinguish a high probability '0' first bit estimate; establishing a third threshold (Vopt) to distinguish first bit estimates between the first and second thresholds; receiving a non-return to zero (NRZ) data stream; comparing the first bit estimate in the data stream to a second bit value received prior to the first bit; comparing the first bit estimate to a third bit value received subsequent to the first bit; in response to the comparisons, determining the value of the first bit.

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Salem, NH, United States of America

Keith Michael Conroy