aDfbrtVt

9 ms·

1.
by aDfbrtVt 1y ago
Depending on phase matching criteria of lambda's on a given core, I would mostly agree that various wavelengths are not significantly coupled. I also agree there are a different power budget for LH modems vs. DCI, but power on LH modem
2.
by aDfbrtVt 1y ago
To get a ballpark power usage, we can look at comparable (for some definition thereof) commercial offerings. Take a public datasheet from Arista[1], they quote 16W typical for a 400Gbps module for 120km of reach. You would need 2500 modems
3.
by aDfbrtVt 1y ago
As others have mentioned, this is mostly a proof of concept for a high core count weakly-coupled fibre from Sumitomo. I also want to highlight the use of a 19 channels MIMO receiver structure which is completely impractical. The linked arti
4.
by aDfbrtVt 3y ago
I can think of a number of cases where using a hard decision decoder can be a better choice. Power would be one factor and I would strongly disagree that the power delta between soft and hard codes at these data rates is small. Unfortunatel
5.
by aDfbrtVt 3y ago
Something not totally clear from the title, but it seems the claimed rate was actually achieve with a transmitter structure similar to what you would find in coherent optics (see figure 4). Instead of coupling to fiber, they couple to a hig
6.
by aDfbrtVt 3y ago
FYI, they recently removed the annual RRSP admin fee. https://www.interactivebrokers.ca/en/index.php?f=rsp_tfsa_in...
7.
by aDfbrtVt 3y ago
Quick correction - not repeaters but amplifiers. The term repeater is commonly used to refer to a device that demodulates and remodulates a signal.
8.
by aDfbrtVt 3y ago
Why so many taps? That's north of 2 seconds.
9.
by aDfbrtVt 3y ago
What is "reliable" though? All digital systems will undergo some rate of correctable/uncorrectable errors, it just depends on what you consider to be an acceptable rate of failure for your device.
10.
by aDfbrtVt 3y ago
That may hold for a trivial device or a perfectly spec compliant device. However, the former is not interesting and the later does not exist. I agree that more test coverage would be beneficial, but I think your heavily downplaying the diff
11.
by aDfbrtVt 3y ago
I fail to see how you could "disrupt" something like cooling solutions in the way I believe your post implies. First, the ability to remove large volumes of heat from a DC (or analogous plant) is largely dependent on the local geo
12.
by aDfbrtVt 3y ago
I would argue the FFT algorithm is much more important in communication systems than the Viterbi algorithm. There are plenty of powerful Forward Error Correction schemes that do not use Convolutional codes (and thus cannot use Viterbi algor
13.
by aDfbrtVt 3y ago
Fun fact, Golay codes are the only perfect code outside of Hamming codes. Perfect codes are interesting in that the Hamming bound becomes an equality, effectively saying that the distance between all valid codewords is exactly the minimum d
14.
by aDfbrtVt 3y ago
Looks like Intel 4nm will only start shipping 2023H2. I'm not sure I see Intel 2nm shipping less than 6 months later, especially given Intel's recent history of stumbling on execution. How firm do you believe the 2024H2 delivery d
15.
by aDfbrtVt 4y ago
I mean yes and no? Kalman filters fuses information about known system behaviour along with observations in an optimal predictor (for certain types of noise). It uses a matrix in the same way that almost every operation on a computer uses a
16.
by aDfbrtVt 4y ago
I have had this page bookmarked for years, hopefully you find it as useful as I do. It is a formal yet digestible treatment of floating point numbers. https://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg
17.
by aDfbrtVt 4y ago
I see, the reduction of antenna gain with terminal miniaturization makes sense. I didn't know if the noise figure of a GaN amplifier was worse. Why would a change in the antenna radiation pattern limit the power spectral density, is it
18.
by aDfbrtVt 4y ago
What aspect of migrating to GaN PA's degrades the link budget for this application?
19.
by aDfbrtVt 4y ago
To further reinforce the above argument, many environments dominated by Matlab have their instrument control software written in Python. Mathworks have made it pretty easy to call out to Python (although no Conda/Venv support...), they
20.
by aDfbrtVt 4y ago
Picard has worked really well for me. https://picard.musicbrainz.org/
21.
by aDfbrtVt 4y ago
Very likely there will be a 1.6T DR4 module in QSPFP-DD/OSFP form factor before 2030 that targets data center interconnects (< 120km). The technology (mostly) exists at this point, though the thermal density and die area pose some c
22.
by aDfbrtVt 4y ago
I don't see much partisanship in this comment section, mostly people discussing the O&G amortization schedules. I agree that, in general, it would be better if HN had less political posts. That said, just upvote the type of posts y
23.
by aDfbrtVt 4y ago
Add the following lines to your sway config. It works for me when using Waybar. exec_always --no-startup-id blueman-applet exec_always --no-startup-id nm-applet --indicator
24.
by aDfbrtVt 4y ago
I would not wish Matlab GUI programming on my worst enemy. I disagree with your assertion that documentation for Python is typically much better. Take a randomly chosen function I regularly use: "pwelch" https://docs.s
25.
by aDfbrtVt 4y ago
I agree with you for the most part, I write this while running Matlab simulations in the background. Having tried to reach similar levels of productivity with Julia or Python, I find the FOSS environments always fall short in the tooling en
26.
by aDfbrtVt 4y ago
I would recommend any of the well reviewed units from the "Tiny Mini Micro" series from Serve the Home. https://www.servethehome.com/introducing-project-tinyminimic... I personally use a Lenovo Tiny M920q purchase
27.
by aDfbrtVt 4y ago
Why would Qualcomm design their silicon for an 8nm Samsung process? They have a working relationship with TSMC and definitely have enough volume to access risk production nodes.
28.
by aDfbrtVt 4y ago
Interesting, the checksum looks like a standard LFSR but uses addition instead of XOR. 1) Seed checkum with initial_value 2) Add a data uint sized to the checksum 3) Shift up by 1 bit while feeding back the MSB to the LSB. 4) GOTO 2 until y
29.
by aDfbrtVt 4y ago
I only see references to a BCH2 ECC in ec.c source file. I would have thought a non-binary code like RS would be better suited to filesystem coding since a fault is likely to corrupt more than a single contiguous bit. I don't have any
30.
by aDfbrtVt 4y ago
Not harder, just different (modulo your definition of old school circuit design).

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