Adaptive Compensation of Bandwidth Narrowing Effect for Coherent In-Phase Quadrature Transponder through Finite Impulse Response Filter

Coherent in-phase quadrature (IQ) transponders are ubiquitous in the long-haul and the metro optical networks. During the transmission, the coherent signal experiences a bandwidth narrowing effect after passing through multiple reconfigurable optical add-drop multiplexers (ROADMs). The coherent signal also experiences a bandwidth narrowing effect when electrical or optical components of the coherent IQ transponder experience aging. A dynamic method to compensate the bandwidth narrowing effect is thus required. In the coherent optical receiver, signal bandwidth is estimated from the raw analog-to-digital converter (ADC) outputs. By adaptively adjusting the tap coefficients of the finite impulse response (FIR) filter, simple post-ADC FIR filters can increase the resiliency of the coherent signal to the bandwidth narrowing effect. The influence of chromatic dispersion, polarization mode dispersion, and polarization dependent loss are studied comprehensively. Furthermore, the bandwidth information of the transmitted analog signal is fed back to the coherent optical transmitter for signal optimization, and the transmitter-side FIR filter thus changes accordingly.

Download Full-text

Discrete biorthogonal wavelets and PR finite impulse response (FIR) filter banks via block circulant matrices

10.1117/12.188811 ◽

1994 ◽

Author(s):

Jaroslav Kautsky ◽

Radka Turcajova

Keyword(s):

Impulse Response ◽

Filter Banks ◽

Finite Impulse Response ◽

Fir Filter ◽

Circulant Matrices ◽

Biorthogonal Wavelets

Download Full-text

Chromatic dispersion and polarization mode dispersion insensitive optical signal to noise ratio monitoring based on electronic variable optical attenuators and optical bandpass filter

10.1117/12.2245939 ◽

2016 ◽

Author(s):

Junde Chang ◽

Bo Liu ◽

Lijia Zhang ◽

Xiangjun Xin ◽

Qi Zhang ◽

...

Keyword(s):

Bandpass Filter ◽

Signal To Noise Ratio ◽

Chromatic Dispersion ◽

Polarization Mode Dispersion ◽

Optical Signal ◽

Polarization Mode ◽

Signal To Noise ◽

Mode Dispersion ◽

Optical Attenuators ◽

Variable Optical Attenuators

Download Full-text

PMD Study & Measurement – Fixed Analyzer Method

Journal of Communications Software and Systems ◽

10.24138/jcomss.v11i4.98 ◽

2015 ◽

Vol 11 (4) ◽

pp. 199 ◽

Cited By ~ 1

Author(s):

Rastislav Motuz ◽

Petr Munster ◽

Miloslav Filka

Keyword(s):

Optical Networks ◽

High Speed ◽

Polarization Mode Dispersion ◽

Main Attention ◽

Laboratory Equipment ◽

Limit Values ◽

Mode Dispersion ◽

Compensation Methods ◽

Accuracy Of Measurements ◽

Modular Platform

The paper theoretically describes Polarization Mode Dispersion (PMD) which is important parameter in high-speed optical networks. Furthermore, compensation methods and measurement principles are presented. Main attention is given to Fixed Analyzer (FA) method that uses common research laboratory equipment in setup. We performed practical measurement of the PMD by using Optical Spectrum Analyzer (OSA) Anritsu MS9740A, in-line polarizers and a polarization controller. To verify the accuracy of measurements Reference Measurement (RM) using a modular platform EXFO FTB-200 in combination with CD/PMD module EXFO FTB-5700 was performed. Moreover, PMD etalons with defined values of delay was used for measurement. All results were evaluated in comparison with defined limit values.

Download Full-text

Low Power Transposed Form 4-Tap Finite Impulse Response Filter using Power Efficient Multiply Accumulate Unit

Journal of Circuits System and Computers ◽

10.1142/s0218126622500165 ◽

2021 ◽

pp. 2250016

Author(s):

S. Rakesh ◽

K. S. Vijula Grace

Keyword(s):

Low Power ◽

Impulse Response ◽

Speech Processing ◽

Video Processing ◽

Filter Design ◽

Finite Impulse Response ◽

Low Power Design ◽

Fir Filter ◽

Efficient Design ◽

Power Efficient

Finite impulse response (FIR) filters find wide application in signal processing applications on account of the stability and linear phase response of the filter. These digital filters are used in applications, like biomedical engineering, wireless communication, image processing, speech processing, digital audio and video processing. Low power design of FIR filter is one of the major constraints that researchers are trying hard to achieve. This paper presents the implementation of a novel power efficient design of a 4-tap 16-bit FIR filter using a modified Vedic multiplier (MVM) and a modified Han Carlson adder (MHCA). The units are coded using Verilog hardware description language and simulated using Xilinx Vivado Design Suite 2015.2. The filter is synthesized for the 7-series Artix field programmable gate array with xc7a100tcsg324-1 as the target device. The proposed filter design showed an improvement of a maximum of 57.44% and a minimum of 2.44% in the power consumption compared to the existing models.

Download Full-text