Multiphy Ltd.

Gilad Katz

Dan Sadot

Albert Gorshtein

Nir Sheffi

Omri Levy

Alik Gorshtein

Ehud Barzilai

Omri Levi

A method for performing blind channel estimation for an MLSE receiver in a communication channel, according to which Initial Metrics Determination Procedure (IMDP) is performed using joint channel and data estimation in a decision directed mode. This is done by generating a bank of initial metrics that assures convergence, based on initial coarse histograms estimation, representing the channel and selecting a first metrics set M from the predefined bank. Then an iterative decoding procedure is activated during which, a plurality of decision-directed adaptation learning loops are carried out to perform an iterative histograms estimation procedure for finely tuning the channel estimation. Data is decoded during each iteration, based on a previous estimation of the channel during the previous iteration. If convergence is achieved, ISI optimization that maximizes the amount of ISI that is compensated by the MLSE is performed.

Blind channel estimation method for an MLSE receiver in high speed optical communication channels

A method for estimating the phase of a modulated complex optical signal, according to which, the phase of the signal is isolated and the complex amplitude of the signal is digitized by a block of P samples. An adaptive filter minimizes phase-error between the phase of the received symbol and the phase of a sample, rotated by a phase correction factor, by iteratively performing a Block-Wise Phase LMS estimation on the samples using a step size parameter. During each iteration, the resulting correction factor consists of the sum of the estimated errors multiplied by this parameter, and the correction factor of previous iteration, which is updated, until obtaining the final correction factor from the last iteration. The samples constituting the received signal are recovered by adding the most updated correction factor to the phase of each sample and performing a decision regarding the phase of each sample.

Hardware efficient implementation of decision feedback phase estimation for an ultra high speed coherent receiver

Method and system for optimally equalizing distortion of an optical data channel carrying coherent optical signals with a given analog bandwidth B. A receiving end with IQ paths receives signals and a balanced detector detects signals in each path. The bandwidth of the detected signals is reduced by a factor of N by filtering the output of each path using an AAF with a cutoff frequency optimized to the analog bandwidth 2B/N of each path, where the AAF has deterministic attributes and introducing Known ISI. The signal is sampled at the AAF output by an ADC, at a sampling rate of 2B/N. The samples of each path are post-processed by a digital processor operating at a data rate of 2B/N, where post-processing represents the compensation of the distortion and the input data stream is reconstructed by optimally decoding the output of the processor using a decoder, which compensates the ISI.

Method and system for coherent equalization of chromatic dispersion of optical signals in a fiber

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Sdema, Israel

Gilad Katz