100Gb/s SMF PMD Alternatives Analysis

Transcription

1 100Gb/s SF D Alternatives Analysis 40Gb/s and 100Gb/s IEEE 80.3 lenary Session San Antonio TX November 01 Chris Bergey Luxtera Sudeep Bhoja Inhi Chris Cole Finisar Ali Ghiasi Broadcom Jonathan King Finisar Ilya Lyubomirsky Finisar Hari Shankar Inhi Brian Welch Luxtera

2 Outline Objectives CAUI-4 Alternatives CAUI- Alternatives Thermal Noise Limited SNR FEC General Case SNR I RIN Future Work November 01

3 Objectives Continue alternatives analysis from ghiasi_01a_091 Develop analysis tools for higher order modulation Compare performance of 80.3bm SF D alternatives November 01 3

4 CAUI-4 5GBaud D Alternatives November 01 4

5 CAUI-4 50GBaud D Alternatives November 01 5

6 CAUI- 50GBaud D Alternatives November 01 6

7 SNR Channel odel hysical Channel Laser Data FEC Encoder Encoded Data Driver Optical odulator Fiber IN TIA CDR FEC Decoder Equivalent AWGN Channel odel Data FEC Encoder Encoded Data Driver & Optical odulator h(t) Fiber IN R E-field N(t) y(t) + _ y(t) TIA + + h(-t) - CDR FEC Decoder E field Optical power = E-field = {0 1-1}D Current levels = {0 1-1}RD TIA output levels = {-(-/ -(-3)/ -1/ 1/ (-/} RD November 01 7

8 Thermal Noise Limited SNR odel Laser RIN not included I not included Noise variance independent of signal amplitude BER specified by a simple formula SNR specified by a single number November 01 8

9 13-15 November 01 9 SNR Definitions D D D D D ( 3 ) log ( ( ( 4( 3 ) log ( ( ( ) log ( ( ( 3 ( ( 3 1 where / ) log ( ( 1 ) ( ( 6 ) ( ( ( ( 3 @ SNR erfc SNR erfc SNR erfc SNR SNR R SNR R R R erfc R R b TIAoutput electrical TIAinput electrical optical TIAoutput electrical TIAinput electrical optical b TIAoutput electrical TIAinput electrical optical

10 SNR enalties: A-N vs. NRZ (A-) 9.1 db 7 db 6.dB 8 db 6.6 db 6.1 db db 5.8 db 5.7 db enalty depends on SNR definition November 01 10

11 SNR Gain with FEC SNR1 (db) SNR (db) SNR3 (db) BER=1.e BER=1.e- 1 FEC Gain (db) = 9.6 =4 10 FEC Gain for SNR1 (db) FEC gain for A-4 assuming FEC threshold at BER=1.e- = November 01 11

12 Amplitude General Case SNR odel Noise is white Gaussian random process with both signal independent thermal noise and signal dependent components due to laser RIN and shot noise. For optimum receiver thresholds the resulting bit error probability is: Q(k) RD/ ( 1 k0 k1 R optical 1 6 electrical@ RD ( ( 1 electrical@ ( ( N k Th qrkd RIN Q( k) ( k) erfc 1 b ( k) ) k k TIAinput TIAoutput RkD ) W (W Rx bandwidth) with BT4 5G BW Time (UI) RD RD RD A single noise variance is not valid Each individual level has its own noise variance SNR has to be defined for each eye Q(k) November 01 1

13 SNR Discussion The ideal case of thermal noise limited systems provides simple BER formulas for comparing modulation formats. The penalty for modulation order depends on the SNR definition; the two should always be stated together. Required FEC gain depends on modulation order; NRZ results are not simply extendable In systems limited by signal dependent noise variance SNR is also level dependent. Segment SNR has to be defined for each eye An overall equivalent SNR is calculated by inverse mapping of BER to SNR November 01 13

14 enalty(dbo) Required RL vs. I enalty ax I penalty: ~1.1 dbo ean I penalty: ~0.8 dbo A-4: -30 db RL A-6: -3 db RL ul path Inteference enalty ER=6.5 db A Con A 4Con A 6Con A-4 Con A-4 4Con A4 6Con A6 Con A6 4Con A6 6Con A8 Con A8 4Con A8 6Con A-8: -34 db RL Single Reflectance RL (db) November 01 14

15 RIN enalty (dbo) Required RIN vs. enalty For ~0.4 dbo average optical penalty min RIN is: db/hz for NRZ db/hz for A-4 Q=4.1 (BER e-5) A-6 Q=3.1 (BER 1e-3) A-8 Q=.0 (BER e-) Level Level 3 Level 4 Level 5 Level 6 Level 7 Level 8 RIN on Each Level A- A-4 A-6 A November 01 15

16 Future Work Jitter Budgets Link Budgets Extension to higher Data Rates November 01 16

17 100Gb/s SF D Alternatives Analysis Thank you November 01 17