Per WP:MOS, articles are to avoid containing information in list or bulleted format (or keep such lists to a minimum). This article is almost exclusively in list format. Regards, --Mattisse 12:14, 29 August 2007 (UTC)
this intro paragraph is ambiguous:
"Frequency modulation (FM) and amplitude modulation (AM) are commonly used methods to modulate the carrier. In the case of single-sideband modulation (SSB) the carrier is suppressed (and in some forms of SSB eliminated). The carrier must be reintroduced at the receiver by a beat frequency oscillator (BFO)."
Does the need to use BFO only apply to SSB or to all FM and AM? I'm gonna go look for that info elsewhere now, but it'd be nice if it was clear here. I'd come back and correct this P myself, but I'm so new to this topic, I wouldn't trust myself.
BTW, I'm also curious about the entropy-information properties of the these waves and what they carry. Would it make sense to add anything about that?
Article needs work
The whole article needs to be reworked.
Why is the carrier wave usually sinusoidal? There should be some discussion of alternative waveforms, and why they were chosen. Is there some history to this? At the very least, a discussion of why sinusoidal waveforms came to be the industrial norm. Dexter Nextnumber (talk) 03:03, 17 December 2009 (UTC)
- A sinusoid packs the maximum possible amount of RF energy in the smallest possible amount of spectrum. If the carrier is not sinusoidal, the modulated signal will take up more bandwidth than generally desired, leading to inefficient use of available spectrum under normal working rules for spectrum use, where different RF emissions are not allowed to share the same band. However, your question is not unreasonable: see direct sequence spread spectrum for how this can be made to work. -- The Anome (talk) 09:58, 7 December 2015 (UTC)
- Firstly, the difficulty of transmitting electromagnetic radiation at baseband, and secondly, the fact that even if you could do so usefully, everyone's signals would overlap. -- The Anome (talk) 09:58, 7 December 2015 (UTC)
Rename to Carrier wave
This meets both WP:COMMONNAME and is also a technically more accurate name.
The carrier wave, of itself, is not a signal and contains no information. Only when it is modulated can it then be said to become a "signal". The purpose of this article is to distinguish this unmodulated carrier from the later forms, and so this distinction is significant and worth emphasising through the article name. Andy Dingley (talk) 11:15, 6 December 2015 (UTC)
- User:The Anome moved this from Carrier wave in 2013. I can't find any discussion about this move but I agree with it. Do you have any evidence for your WP:COMMONNAME assertion? ~Kvng (talk) 14:55, 6 December 2015 (UTC)
- @Andy Dingley: I'm convinced by the argument above, and have moved it back. In the context of RF transmission, "carrier signal" is also to some extent justifiable on those grounds (the "signal" in this case is "this channel is taken") but I take Andy Dingley's point. -- The Anome (talk) 15:00, 6 December 2015 (UTC)