Applied Micro Circuits Corporation

L-3 Communications Titan Corporation

Omer Acikel

Keith Michael Conroy

Warm Shaw Yuan

Francesco Caggioni

Alan Michael Sorgi

Daniel M Castagnozzi

John Wiss

A system and method are provided for creating codewords using common partial parity products. The method initially accepts an algorithm for creating p indexed parity bit positions, where the parity bit for each position is calculated from mathematical operations performed on bits from n indexed user word positions. A first group of parity bit positions is found, where the parity bit for each position in the first group is calculated using at least a first number of common mathematical operations. A second group of parity bit positions is found, where the parity bit for each position in the second group is calculated using at least a second number of common mathematical operations. The common mathematical operations are subtracted from the first and second group of parity bit position calculations, so that unique mathematical operations can be found, associated with each parity bit position calculation in the first and second group.

System and method for encoding using common partial parity products

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

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

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 non-causal channel equalization in a communications system. The method comprises: establishing three thresholds; receiving a binary serial 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; data stream inputs below the first threshold and above the third threshold are a '0' if both the second and third bits are '1' values, and as a &#x201c;1&#x201d; if either of the second and third values is a &#x201c;1&#x201d;; data stream inputs above the second threshold and below the third threshold are a &#x201c;1&#x201d; if both the second and third bits are a &#x201c;0&#x201d; value, and as a &#x201c;0&#x201d; if either of the second and third values is a &#x201c;0&#x201d;.

Multi-threshold channel equalization

Non-causal channel equalization system

The tracking of the phase of a received signal having a known preamble is accomplished by the steps of: initializing a phase-locked loop in accordance with estimated phase parameters, which are generated during an estimation interval by processing samples of the known preamble; delaying the preamble; generating phase error parameters by processing samples of the delayed preamble; and training the phase locked loop by tracking the phase-tracked signal in accordance with the tracking error parameters during a training interval after the estimation interval. The timing of the sampling is likewise trained in a closed timing loop in accordance with timing error parameters generated during the training interval after the timing loop has been initialized by estimated timing parameters generated during the estimation interval. The duration of the delay of the preamble is one-half the duration of the estimation interval.

Tracking the phase of a received signal

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 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

Non-causal channel equalization

A state machine method and system are provided for determining non-causal channel equalization thresholds. The method comprises: receiving a non-return to zero (NRZ) data stream encoded with forward error correction (FEC); setting x=0; in State, adjusting a third threshold (Vopt) in response to corrected bit errors; if x=0, setting a first and second threshold equal to the third threshold; in State, if x=0, simultaneously adjusting the first threshold and the second threshold, to minimize the total number of corrected bit errors; in State, following State, adjusting the first threshold, independent of the second threshold, to minimize the total number of errors; in State, following State, adjusting the second threshold, independent of the first threshold, to minimize the total number of errors; and, adding 1 to x and returning to State

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San Diego, CA, United States of America

Omer Acikel