Converting to dBm from pwelch function

2013 7 31
1 个回答
7 次查看（30 天）

0 个投票

How do I convert Pxx that I get from using the pwelch to dBm. I know we can convert to dB by 10*log10(Pxx) but I was unsure how we would do it to get dBm.

请先登录，再回答此问题。

回答（1 个）

Wayne King
Wayne King 2013-7-31
编辑：Wayne King 2013-7-31

0 个投票

Since 1 milliwatt is 0 dBm, you can do the following:
10*log10(1e3*Pxx)
from the above, you see that a power of 1 milliwatt will equal 0 dBm.
or equivalently,
10*log10(Pxx)+30

3 个评论
显示 1更早的评论 隐藏 1更早的评论

Divya Venkatesha
Divya Venkatesha 2013-8-1
Hi Wayne,
Thanks for your reply. I tried that and it doesnt seem to stack up. I have an input power level of -80 and if I add 30 to the 10log10(Pxx) I get 71dB which gives me a gain of 151dB. But I have tried using voltages and the gain should be 75dB which is also verified by simulations. So I am really not sure what units Pxx has. Any feed back will be appreciated.
Many Thanks Divya
Wayne King
Wayne King 2013-8-1
What units is your input time series in?

请先登录，再进行评论。

类别

在 帮助中心 和 File Exchange 中查找有关 Spectral Estimation 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by