周波数帯域
周波数のはば
aka. 帯域幅とも言う。
帯≒域≒幅
トリプル冗語ぢゃんwint.icon
Δだろうと、単位は周波数なので Hz である。
定義式
次元: 周波数 Hz
帯域 (ΔHz = Hz) = 上限 (Hz) − 下限 (Hz) = ub - lb
範囲
baseband
passband
性質
高周波数帯ほど帯域幅を稼げるのは、単位時間あたりの波数が多いから。
cf. zero crossing
通過帯域 = passband
通信経路の容量は、この相対的な幅にしか比例せず、絶対的な周波数の値からは独立してる。
つまり、どこを切り取って使っても良い。
変調できる要素
振幅 A
amp
周波数 f
freq
位相 θ
en: phase
利用
アナログ通信
電話
電話網の幹線となる中継回線はデジタル。具体的には光ファイバー。 subnet 相当。
デジタル通信
有線・無線様々
ref.
https://wa3.i-3-i.info/diff895communication.html
Zero crossing - Wikipedia
Zero-crossing rate - Wikipedia
Bing AI
me
Why is it that the higher the frequency band, the more bandwidth you can gain?
Higher-frequency transmissions have more bandwidth than lower-frequency transmissions, which means higher-frequency transmissions can send substantially more data between devices in less time¹. If a signal has more bandwidth—in this case meaning that it includes or is compatible with higher frequencies—it can change more rapidly. Thus, more bandwidth corresponds to a higher maximum rate of data transfer⁵. Higher-frequency signals make more crossings, and therefore can represent more symbols. And that is why millimeter wave signals have such high bandwidth: there are simply so many more zero crossings in any unit of time, compared to lower-frequency signals⁶.
I hope that helps!
Source: Conversation with Bing, 2023/3/31
(1) The Advantages of Higher Bandwidth Frequencies | Techwalla. https://www.techwalla.com/articles/the-advantages-of-higher-bandwidth-frequencies Accessed 2023/3/31.
(2) Why does bandwidth increase with frequency? - Alnaql-Alkahrabayiyu. https://alnaql-alkahrabayiyu.com/qa/why-does-bandwidth-increase-with-frequency.html Accessed 2023/3/31.
(3) Does higher-frequency mean more bandwidth? – Wise-Answer. https://wise-answer.com/does-higher-frequency-mean-more-bandwidth/ Accessed 2023/3/31.
(4) Why does more bandwidth guarantee high bit rate?. https://electronics.stackexchange.com/questions/272658/why-does-more-bandwidth-guarantee-high-bit-rate Accessed 2023/3/31.
(5) Why doesn't higher frequency mean higher data rate?. https://electronics.stackexchange.com/questions/504401/why-doesnt-higher-frequency-mean-higher-data-rate Accessed 2023/3/31.
(6) Why do higher frequencies allow for larger bandwidths? - Quora. https://www.quora.com/Why-do-higher-frequencies-allow-for-larger-bandwidths Accessed 2023/3/31.
(7) Why do higher frequencies mean higher data rates, and why do we even .... https://electronics.stackexchange.com/questions/84245/why-do-higher-frequencies-mean-higher-data-rates-and-why-do-we-even-need-freque Accessed 2023/3/31.
(8) Does higher frequency mean more bandwidth? - Quora. https://www.quora.com/Does-higher-frequency-mean-more-bandwidth Accessed 2023/3/31.
disambiguation
vs. 帯域
こっちは通信速度のこと
#違いシリーズ
#通信 #telecommunication