[Discuss-gnuradio] Question about OpenBTS BM 2009 RF chains
From:
hanwen
Subject:
[Discuss-gnuradio] Question about OpenBTS BM 2009 RF chains
Date:
Tue, 8 Sep 2009 15:22:53 +0200
Hi,
I read the following article describing the RF chain of OpenBTS will be used in BM'09. http://sourceforge.net/apps/trac/openbts/wiki/OpenBTS/BM2009RF
In the "RX/TX isolation" part, it says that "The USRP outputs noise in the receive band about 80 dB below the transmit signal level, or around -60 dBm.". Does the USRP outputs noise in the receive band mean the out-band leakage of transmitted signal? And why it is around 20dBm - 80dB = -60dBm, but not 36dBm - 80dB = -44dBm. In my opinion, the leakage signal is also amplified by PA.