Talk:Water-filling algorithm

This is quite poorly written and hard to understand, anyone with a good understanding of the topic willing to improve?

This article seems at odds with mainstream communications engineering. For example transmit power adjustment in order to compensate for channel losses in a single-input single-output channel would not typically be regarded as an example of water-filling.

Unlike this article, another article water-pouring algorithm on exactly the same topic does seem in line with mainstream communications engineering and has more pertinent references, so it could be a better basis for improvements. One needed improvement is that you should get there when looking for "water-filling", which is perhaps a more common term than "water-pouring". — Preceding unsigned comment added by Contributor7545 (talk • contribs) 12:25, 14 October 2015 (UTC)

I agree with all of your comments. When I get time I make make some changes. Sanpitch (talk) 18:26, 19 June 2024 (UTC)

Merge proposal: Water-pouring algorithm

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.

The result of this discussion was Merge to Water-filling algorithm. Elestrophe (talk) 04:43, 23 July 2025 (UTC)

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Related to the above topic: I propose merging water-pouring algorithm into water filling algorithm. Both articles are stubs about the exact same topic, but "water-filling algorithm" seems to be a significantly more common term. Currently water-pouring algorithm has the worse name but somewhat better content, so it would be good to merge that content here as a starting point for further improvements.

I also intend to move this page to "Water-filling algorithm" (with the hyphen) if there are no objections.

@Photonique, Blanchardb, Srleffler, Mogism, Contributor7545, Tom.Reding, Michael Hardy, McId, Yobot, Hkettani, Rivertorch, Monkbot, Cnwilliams, and Skullcinema

Elestrophe (talk) 04:05, 30 June 2025 (UTC)

Yes, but merge to Water-filling algorithm instead (grammar).--Srleffler (talk) 06:18, 30 June 2025 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Disagreement between SNR sentence and power allocation sentence

These sentences don’t make sense to me:

Each of the available channels is then a section of the container having its own depth, given by the reciprocal of the frequency-dependent SNR for the channel.

SNR is signal-to-noise. A larger SNR value means a better channel (more signal and/or less noise). Taking the reciprocal inverts that: the reciprocal is larger if the SNR is smaller. So, if the depth of the section is given by the reciprocal of the SNR, then the better (higher-SNR) channels have shallower (lower-depth) sections and the worse (lower-SNR) channels have deeper (higher-depth) sections.

To allocate power, imagine pouring water into this container (the amount depends on the desired maximum average transmit power). After the water level settles, the largest amount of water is in the deepest sections of the container.

These sentences claim that more water (power) is in the deeper (worse-quality, lower-SNR) sections and less water (power) is in the shallower (better-quality, higher-SNR) sections.

This implies allocating more power to the channels with the most favourable SNR.

This sentence directly contradicts the previous, stating that better (higher-SNR) channels get more, not less, power.

Can anyone resolve this? Thanks. Hawk777 (talk) 01:49, 16 July 2026 (UTC)