Equalization and near-end crosstalk (NEXT) noise cancellation for 20-Gbit/sec 4-PAM backplane serial I/O interconnections |
Posted on:2006-10-04 | Degree:Ph.D | Type:Dissertation |
University:Georgia Institute of Technology | Candidate:Hur, Young Sik | Full Text:PDF |
GTID:1458390005992928 | Subject:Engineering |
Abstract/Summary: | |
A combined solution of the Feed-Forward Equalizer (FFE) and Near-End Crosstalk (NEXT) noise cancellation technique was suggested. The techniques increase data throughput and improve link quality in the 20-in FR4 legacy backplane application. Backplane channel loss and coupling noise were measured and characterized to develop the corresponding behavioral channel model.; The receiver-side FFE with 4-tap Finite Impulse Response (FIR) filter structure was adopted as the optimum equalizer topology. The 4-tap FIR filter consists of tap delay line with tap-spacing 33 ps and linear tap-gain amplifiers. The tap coefficients were calculated with the Minimum-Mean-Squared-Error (MMSE) algorithm. A 0.18-um CMOS 4-tap FIR filter IC was designed and fabricated. The experiment results showed the 20-Gbit/sec 4-PAM and 10-Gbit/sec NRZ signal were successfully equalized for the 20-in FR4 legacy backplane channel.; Moreover, the suggested NEXT noise cancellation technique consists of coarse- and fine-cancellation stages. The 0.18-um CMOS building block ICs such as 7-tap FIR filter, tunable active Pole-Zero (PZ) filter, and a temporal alignment delay line were fabricated. The experiment results showed that 6-dB Signal-to-Noise Ratio (SNR) improvement was achieved by the developed NEXT noise cancellation technique. |
Keywords/Search Tags: | Noise cancellation, NEXT, FIR filter, Backplane |
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